Gentlemen,
I'm in the process of trying to track down a fault in my main HP spectrum >analyzer. I've narrowed the issue down to the area of this "sampler" which
is part of a phase locked loop. I'm not sure I fully understand its
function, however. In particular, I'm extremely confused as to why they're >calling it a "sampler" because when that term arises, I typically think of >something doing akin to what a sampling oscilloscope does: noting voltage >levels at predetermined intervals. AFAICS, this "sampler" is doing no such >thing. It's just a harmonic mixer, surely? If not, I must be nuts. YOU get
to decide!
Block diagram here: https://disk.yandex.com/i/YXcGssgDXwVEbg
Short functional description here:
https://disk.yandex.com/i/k7YTYTGjHltsGw
On Sun, 28 Jul 2024 17:31:52 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
Gentlemen,
I'm in the process of trying to track down a fault in my main HP
spectrum analyzer. I've narrowed the issue down to the area of this >>"sampler" which is part of a phase locked loop. I'm not sure I fully >>understand its function, however. In particular, I'm extremely confused
as to why they're calling it a "sampler" because when that term arises,
I typically think of something doing akin to what a sampling
oscilloscope does: noting voltage levels at predetermined intervals. >>AFAICS, this "sampler" is doing no such thing. It's just a harmonic
mixer, surely? If not, I must be nuts. YOU get to decide!
Short functional description here:
https://disk.yandex.com/i/k7YTYTGjHltsGw
From the description, it sounds just like the circuit of a sampling oscilloscope. An SRD impulse generator and some diodes, probably.
Post the schematic of the sampler circuit.
A sampler IS a harmonic mixer.
Gentlemen,
I'm in the process of trying to track down a fault in my main HP spectrum analyzer. I've narrowed the issue down to the area of this "sampler" which
is part of a phase locked loop. I'm not sure I fully understand its
function, however. In particular, I'm extremely confused as to why they're calling it a "sampler" because when that term arises, I typically think of something doing akin to what a sampling oscilloscope does: noting voltage levels at predetermined intervals. AFAICS, this "sampler" is doing no such thing. It's just a harmonic mixer, surely? If not, I must be nuts. YOU get
to decide!
Block diagram here: https://disk.yandex.com/i/YXcGssgDXwVEbg
Short functional description here:
https://disk.yandex.com/i/k7YTYTGjHltsGw
On 7/28/2024 1:31 PM, Cursitor Doom wrote:
Gentlemen,
I'm in the process of trying to track down a fault in my main HP spectrum
analyzer. I've narrowed the issue down to the area of this "sampler" which >> is part of a phase locked loop. I'm not sure I fully understand its
function, however. In particular, I'm extremely confused as to why they're >> calling it a "sampler" because when that term arises, I typically think of >> something doing akin to what a sampling oscilloscope does: noting voltage
levels at predetermined intervals. AFAICS, this "sampler" is doing no such >> thing. It's just a harmonic mixer, surely? If not, I must be nuts. YOU get >> to decide!
Block diagram here: https://disk.yandex.com/i/YXcGssgDXwVEbg
Short functional description here:
https://disk.yandex.com/i/k7YTYTGjHltsGw
Too bad they don't call it a "frequency sampler".
In essence (perhaps over simplified) that's
what it does. It produces the frequencies above
and below the center frequency (the spectrum) to
be portrayed on the screen. As you noted, it does
that by harmonic mixing. You might want to think
about it with a change in your statement about an
oscilloscope:
From "noting voltage levels at predetermined intervals."
to "noting voltage levels at predetermined frequencies."
Maybe that helps.
Ed
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The signal from the LHS is passed through a very fast diode which generates harmonics from that fundamental. The signal from the RHS is unmodified and mixed with the desired harmonic to give the necessary output signal which
is then filtered to get rid of the unwanted mixing products. If that's all correct, as I believe it is, where does any *sampling* come into it?
On Sun, 28 Jul 2024 10:41:26 -0700, john larkin wrote:
On Sun, 28 Jul 2024 17:31:52 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
Gentlemen,
I'm in the process of trying to track down a fault in my main HP
spectrum analyzer. I've narrowed the issue down to the area of this >>>"sampler" which is part of a phase locked loop. I'm not sure I fully >>>understand its function, however. In particular, I'm extremely confused >>>as to why they're calling it a "sampler" because when that term arises,
I typically think of something doing akin to what a sampling
oscilloscope does: noting voltage levels at predetermined intervals. >>>AFAICS, this "sampler" is doing no such thing. It's just a harmonic >>>mixer, surely? If not, I must be nuts. YOU get to decide!
Short functional description here: >>>https://disk.yandex.com/i/k7YTYTGjHltsGw
From the description, it sounds just like the circuit of a sampling
oscilloscope. An SRD impulse generator and some diodes, probably.
Post the schematic of the sampler circuit.
A sampler IS a harmonic mixer.
This - see link - is about as much detail as they provide. Seems the >"sampler" is perhaps proprietory and they don't want it copied I would
guess.
https://disk.yandex.com/i/0p1smcx2qgV1Qg
I don't know how you equate a sampler to a harmonic mixer; I don't see any >similarity at all.
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:and you
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a
mixer. Come to think of it, I don't really know anything about them other than you input two different frequency signals which intermodulate
get the sum and the difference of them at the output; then filter for the one you need. Is this intermodulation some form of sampling?
On 2024-07-28 19:04, Cursitor Doom wrote:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's nothing analagous to that going on with this device AFAICS.other
Perhaps I don't have a good enough understanding of what happens in a mixer. Come to think of it, I don't really know anything about them
than you input two different frequency signals which intermodulateand you
get the sum and the difference of them at the output; then filter forthe
one you need. Is this intermodulation some form of sampling?
More or less, sometimes a lot more. Here goes.
**FREQUENCY MIXING**
In signal processing theory, we often model a mixer as multiplying the
RF input signal by a sinusoidal local oscillator (LO) to produce the intermediate frequency (IF) output. ['IF' isn't a great name, because
it sounds like there's only one frequency there. In fact there are
nearly always lots of components at different frequencies, which we have
to separate with filters.]
That’s mathematically pretty simple, requiring only the formulas for products of sines and cosines. Those are simple to derive from the definitions if you forget which way the signs go. For reference,
cos(a+b) = cos a cos b - sin a sin b (1)
cos(a-b) = cos a cos b + sin a sin b (2)
so
sin a sin b = 0.5 * [ cos(a-b) - cos(a+b) ]Â (3) and
cos a cos b = 0.5 * [ cos(a-b) + cos(a+b) ]Â (4)
the sin * cos versions come from the formula for sin(a+b), and are left
as an exercise for the reader. ;)Â (In real life, you can put the phase shifts into the arguments rather than using different formulas.)
Mixers like this are said to be *bilinear*, because they're linear in
both inputs--if you multiply 2x * y, or x * 2y, you get 2xy.
The net is that you get two copies of your signal, one upshifted by the
LO frequency and the other downshifted. (There’s an absolute value in
the downshifted frequency, because it’s convenient to deal with positive frequencies.)(*)
**SWITCHING MIXERS**
Most real mixers are a bit different, because linear mixing is hard to
do well. A radio has to deal with whatever comes in from the antenna,
which may well include other signals that are much stronger than the one
you want, and a bad mixer will cause all sorts of problems when that happens. (Search for 'cross modulation' for one example. Ignore the AI results.)
Thus most mixers are switching types, which are effectively multipliers
where the LO is a fixed-amplitude square wave rather than a variable-amplitude sine. You can verify with your favorite math program that a square wave
SQ(t) = 1Â Â 0< t < pi
     = -1 pi < t < 2*pi (and so on) (5)
is given by
SQ(t) = sin(t) + sin(3 t)/3 + sin(5 t)/ 5 +.... , (6)
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >signal from the LHS is passed through a very fast diode which generates >harmonics from that fundamental. The signal from the RHS is unmodified and >mixed with the desired harmonic to give the necessary output signal which
is then filtered to get rid of the unwanted mixing products. If that's all >correct, as I believe it is, where does any *sampling* come into it?
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >signal from the LHS is passed through a very fast diode which generates >harmonics from that fundamental. The signal from the RHS is unmodified and >mixed with the desired harmonic to give the necessary output signal which
is then filtered to get rid of the unwanted mixing products. If that's all >correct, as I believe it is, where does any *sampling* come into it?
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a
mixer. Come to think of it, I don't really know anything about them other >than you input two different frequency signals which intermodulate and you >get the sum and the difference of them at the output; then filter for the
one you need. Is this intermodulation some form of sampling?
On Sun, 28 Jul 2024 21:40:41 -0000 (UTC), Cursitor Doom ><cd999666@notformail.com> wrote:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >>signal from the LHS is passed through a very fast diode which generates >>harmonics from that fundamental. The signal from the RHS is unmodified and >>mixed with the desired harmonic to give the necessary output signal which >>is then filtered to get rid of the unwanted mixing products. If that's all >>correct, as I believe it is, where does any *sampling* come into it?
Mixing = sampling = multiplication.
On 2024-07-28 21:16, Phil Hobbs wrote:
On 2024-07-28 19:04, Cursitor Doom wrote:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:other
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's
nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a
mixer. Come to think of it, I don't really know anything about them
than you input two different frequency signals which intermodulateand you
get the sum and the difference of them at the output; then filter forthe
one you need. Is this intermodulation some form of sampling?
More or less, sometimes a lot more. Here goes.
**FREQUENCY MIXING**
In signal processing theory, we often model a mixer as multiplying the
RF input signal by a sinusoidal local oscillator (LO) to produce the
intermediate frequency (IF) output. ['IF' isn't a great name, because
it sounds like there's only one frequency there. In fact there are
nearly always lots of components at different frequencies, which we have
to separate with filters.]
That’s mathematically pretty simple, requiring only the formulas for
products of sines and cosines. Those are simple to derive from the
definitions if you forget which way the signs go. For reference,
cos(a+b) = cos a cos b - sin a sin b (1)
cos(a-b) = cos a cos b + sin a sin b (2)
so
sin a sin b = 0.5 * [ cos(a-b) - cos(a+b) ] (3) and
cos a cos b = 0.5 * [ cos(a-b) + cos(a+b) ] (4)
the sin * cos versions come from the formula for sin(a+b), and are left
as an exercise for the reader. ;) (In real life, you can put the phase
shifts into the arguments rather than using different formulas.)
Mixers like this are said to be *bilinear*, because they're linear in
both inputs--if you multiply 2x * y, or x * 2y, you get 2xy.
The net is that you get two copies of your signal, one upshifted by the
LO frequency and the other downshifted. (There’s an absolute value in
the downshifted frequency, because it’s convenient to deal with positive
frequencies.)(*)
**SWITCHING MIXERS**
Most real mixers are a bit different, because linear mixing is hard to
do well. A radio has to deal with whatever comes in from the antenna,
which may well include other signals that are much stronger than the one
you want, and a bad mixer will cause all sorts of problems when that
happens. (Search for 'cross modulation' for one example. Ignore the AI
results.)
Thus most mixers are switching types, which are effectively multipliers
where the LO is a fixed-amplitude square wave rather than a
variable-amplitude sine. You can verify with your favorite math program
that a square wave
SQ(t) = 1 0< t < pi
= -1 pi < t < 2*pi (and so on) (5)
is given by
SQ(t) = sin(t) + sin(3 t)/3 + sin(5 t)/ 5 +.... , (6)
(There's actually a factor of 4/pi in front of all that, which I forgot >about. Otherwise OK.)
Cheers
Phil Hobbs
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor >Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>mixer. Come to think of it, I don't really know anything about them other >>than you input two different frequency signals which intermodulate and you >>get the sum and the difference of them at the output; then filter for the >>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator.
When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >etc...
On Mon, 29 Jul 2024 05:24:31 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor >>Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >>>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>>mixer. Come to think of it, I don't really know anything about them other >>>than you input two different frequency signals which intermodulate and you >>>get the sum and the difference of them at the output; then filter for the >>>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator.
When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >>etc...
I don't see the relevance here. If by 'sampling gate' you mean 'sample
& hold' - which I assume you do - that's a different part of the loop >altogether from the part labled 'sampler' in the block diagram.
On a sunny day (Mon, 29 Jul 2024 12:06:31 +0100) it happened Cursitor Doom ><cd@notformail.com> wrote in <7qteaj94r7l8n9ct4h16kviugq6shkp384@4ax.com>:
On Mon, 29 Jul 2024 05:24:31 GMT, Jan Panteltje <alien@comet.invalid> >>wrote:
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor >>>Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked >>>>> wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >>>>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>>>mixer. Come to think of it, I don't really know anything about them other >>>>than you input two different frequency signals which intermodulate and you >>>>get the sum and the difference of them at the output; then filter for the >>>>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator.
When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >>>etc...
I don't see the relevance here. If by 'sampling gate' you mean 'sample
& hold' - which I assume you do - that's a different part of the loop >>altogether from the part labled 'sampler' in the block diagram.
Idujno,Ifind that diagram very much crap, more a block diagram
I wonder, did you EVER design any electronics?
Try building a sampling circuit, or that instrument you are carrying on about >to get a feel for what counts, so you CAN do fast fault finding.
Else endless blur makes you see nothing.
Should take 10 minutes to fix the thing if you did not damage it before hand.
On Sun, 28 Jul 2024 19:16:10 -0700, john larkin
<jlarkin_highland_tech> wrote:
On Sun, 28 Jul 2024 21:40:41 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The
signal from the LHS is passed through a very fast diode which generates
harmonics from that fundamental. The signal from the RHS is unmodified and >>> mixed with the desired harmonic to give the necessary output signal which >>> is then filtered to get rid of the unwanted mixing products. If that's all >>> correct, as I believe it is, where does any *sampling* come into it?
Mixing = sampling = multiplication.
Apples = oranges = pears is an equally valid statement!
On Mon, 29 Jul 2024 05:24:31 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor >>Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked
wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >>>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>>mixer. Come to think of it, I don't really know anything about them other >>>than you input two different frequency signals which intermodulate and you >>>get the sum and the difference of them at the output; then filter for the >>>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator.
When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >>etc...
I don't see the relevance here. If by 'sampling gate' you mean 'sample
& hold' - which I assume you do - that's a different part of the loop >altogether from the part labled 'sampler' in the block diagram.
On Mon, 29 Jul 2024 11:30:08 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Mon, 29 Jul 2024 12:06:31 +0100) it happened Cursitor Doom >><cd@notformail.com> wrote in <7qteaj94r7l8n9ct4h16kviugq6shkp384@4ax.com>:
On Mon, 29 Jul 2024 05:24:31 GMT, Jan Panteltje <alien@comet.invalid> >>>wrote:
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor >>>>Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked >>>>>> wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >>>>>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>>>>mixer. Come to think of it, I don't really know anything about them other >>>>>than you input two different frequency signals which intermodulate and you >>>>>get the sum and the difference of them at the output; then filter for the >>>>>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator.
When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >>>>etc...
I don't see the relevance here. If by 'sampling gate' you mean 'sample
& hold' - which I assume you do - that's a different part of the loop >>>altogether from the part labled 'sampler' in the block diagram.
Idujno,Ifind that diagram very much crap, more a block diagram
Yes, it's a block diagram which shows the device labeled as a
"sampler" comes before the phase detector, after which comes the
sample and hold part.
I wonder, did you EVER design any electronics?
No. And I've never made any secret of that here.
Try building a sampling circuit, or that instrument you are carrying on about >>to get a feel for what counts, so you CAN do fast fault finding.
Else endless blur makes you see nothing.
Should take 10 minutes to fix the thing if you did not damage it before hand.
I can't fix it if I don't fully understand what it does, hence the
original question.
Anyway, it's clear that regardless of what HP call the thing, it's
just a harmonic mixer and if I proceed on that basis, I should be able
to trace the issue.
On a sunny day (Mon, 29 Jul 2024 12:50:33 +0100) it happened Cursitor Doom ><cd@notformail.com> wrote in <p80fajltc50rajhib7dqjn6mbni6d8ko6q@4ax.com>:
On Mon, 29 Jul 2024 11:30:08 GMT, Jan Panteltje <alien@comet.invalid> >>wrote:
On a sunny day (Mon, 29 Jul 2024 12:06:31 +0100) it happened Cursitor Doom >>><cd@notformail.com> wrote in <7qteaj94r7l8n9ct4h16kviugq6shkp384@4ax.com>: >>>
On Mon, 29 Jul 2024 05:24:31 GMT, Jan Panteltje <alien@comet.invalid> >>>>wrote:
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor
Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>: >>>>>
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked >>>>>>> wheels of wagons seemed to turn backwards in certain speed ranges. >>>>>>I can get my head around that kind of sampling no problem. But there's >>>>>>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>>>>>mixer. Come to think of it, I don't really know anything about them other >>>>>>than you input two different frequency signals which intermodulate and you
get the sum and the difference of them at the output; then filter for the >>>>>>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator. >>>>>When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >>>>>etc...
I don't see the relevance here. If by 'sampling gate' you mean 'sample >>>>& hold' - which I assume you do - that's a different part of the loop >>>>altogether from the part labled 'sampler' in the block diagram.
Idujno,Ifind that diagram very much crap, more a block diagram
Yes, it's a block diagram which shows the device labeled as a
"sampler" comes before the phase detector, after which comes the
sample and hold part.
I wonder, did you EVER design any electronics?
No. And I've never made any secret of that here.
Try building a sampling circuit, or that instrument you are carrying on about
to get a feel for what counts, so you CAN do fast fault finding.
Else endless blur makes you see nothing.
Should take 10 minutes to fix the thing if you did not damage it before hand.
I can't fix it if I don't fully understand what it does, hence the
original question.
Anyway, it's clear that regardless of what HP call the thing, it's
just a harmonic mixer and if I proceed on that basis, I should be able
to trace the issue.
So, as to that block diagram
They come in with 177 to 187 MHz to one side of 'sampler'
and with 2.3 GHz to 6.1 GHz on the other side of 'sampler'.
Sampler is followed by a 70 MHz lowpass
And then out the 'sampler' comes 20 MHz to 30 MHz
input is 10 MHz wide, output is 10 MHz wide, so far so good, if it is some mixer
But mixing GHz with a few MHz does not give MHz signals
It gets worse, the output of 20 to 30 MHz is then devided by 2 to 10 to 15 MHz >and compared to 15 to 30 MHz divided by 2 from 'syntesizer' and used to drive 'FM coil driver'.
and looks like used to FM (FM coil driver) modulate that 2.3 to 6.1 GHz oscillator.
Now in case of FM modulation sidebands will be all over the place (all just a few MHz apart in this case)...
Now here comes a clue, those sidebands WILL interact with the 177 to 187 MHz >Not much but some...
OTOH not all documentation is written by the designers, so maybe the numbers are different...
;-)
Setup seem bizarre, better get a cheap Chinese meter from ebay.
If you do not design anything why bother with old rusty boat anchors...
I do not have any and all stuff works here.
Start building something simple, and take it from there.
Crystal radio?
/
Do not get hung up in math.
maaaz is used everywhere and people think it is reality, like 'space is curved' crap.
Get a decent analog scope and start with some radios or transmitters, or maybe a light bulb, or whatever have you.
As a kid I started with checking if the 4.5 battery was full with my tongue, build my own scope many years later...
I did not even have a multimeter, just a uA meter and some resistors...
And yes I had a home build TV running in my room.
Later after school working for a power company I designed and build my own vidicon portabe camera, changed jobs gave me a job at
the national TV network..
Fault finding:? the show must go on - NOW - regardless of stressed producers... artists waiting.. whole country watching,
global networks, remote locations, no black screen allowed...
Video, audio, tape recording, 35 mm film, projectors, film scanners, studios were something else those days.
Boat anchors? you have not seen it yet :-) Rooms full of tubes... monitors, scopes on each video recorder, synchronisation
stuff..
Now a youtube channel is all you need and a few dollies ($$) will buy you all you need.
Some equipment we used back then did cost a few million...
Oh well, OK start with a crystal radio perhaps... That is what I did, oh and tubes and record players ... oh and ..
that was in primary school days, then in highschool: amplifier for the school band and a FM radio transmitter for the music we
made..
electronics is fun,
programming can be too, but that came much later...
It is remarkable that when in those eighties US landed on the moon, I was in the TV head control room here to relay it to the
people in my country,
and now with all them sup[p]er computahs astronuts are stuck due to some helium leaks in some thrusters endlessly driving
around the block.
Now with US IQ dropping to single digit values and as China already got stuff back from the backside of the moon..
where will it go...
Will that US union fall apart? Will it get so hot they will all flee to Canada?
On Mon, 29 Jul 2024 11:30:08 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Mon, 29 Jul 2024 12:06:31 +0100) it happened Cursitor Doom >><cd@notformail.com> wrote in <7qteaj94r7l8n9ct4h16kviugq6shkp384@4ax.com>:
On Mon, 29 Jul 2024 05:24:31 GMT, Jan Panteltje <alien@comet.invalid> >>>wrote:
On a sunny day (Sun, 28 Jul 2024 23:04:45 -0000 (UTC)) it happened Cursitor >>>>Doom <cd999666@notformail.com> wrote in <v86iqd$3n74$2@dont-email.me>:
On Sun, 28 Jul 2024 20:28:25 -0000 (UTC), Phil Hobbs wrote:
Stroboscopic sampling is familiar from old Westerns, where the spoked >>>>>> wheels of wagons seemed to turn backwards in certain speed ranges.
I can get my head around that kind of sampling no problem. But there's >>>>>nothing analagous to that going on with this device AFAICS.
Perhaps I don't have a good enough understanding of what happens in a >>>>>mixer. Come to think of it, I don't really know anything about them other >>>>>than you input two different frequency signals which intermodulate and you >>>>>get the sum and the difference of them at the output; then filter for the >>>>>one you need. Is this intermodulation some form of sampling?
Consider a simple PLL with a sampling gate as phase discriminator.
When the frequencies are equal the output is some DC value, its amplitude depending on the phase difference.
When one frequency goes a bit up, the output is the difference frequency. >>>>etc...
I don't see the relevance here. If by 'sampling gate' you mean 'sample
& hold' - which I assume you do - that's a different part of the loop >>>altogether from the part labled 'sampler' in the block diagram.
Idujno,Ifind that diagram very much crap, more a block diagram
Yes, it's a block diagram which shows the device labeled as a
"sampler" comes before the phase detector, after which comes the
sample and hold part.
I wonder, did you EVER design any electronics?
No. And I've never made any secret of that here.
Try building a sampling circuit, or that instrument you are carrying on about >>to get a feel for what counts, so you CAN do fast fault finding.
Else endless blur makes you see nothing.
Should take 10 minutes to fix the thing if you did not damage it before hand.
I can't fix it if I don't fully understand what it does, hence the
original question.
Anyway, it's clear that regardless of what HP call the thing, it's
just a harmonic mixer and if I proceed on that basis, I should be able
to trace the issue.
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened Cursitor >Doom <cd999666@notformail.com> wrote in <v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >>signal from the LHS is passed through a very fast diode which generates >>harmonics from that fundamental. The signal from the RHS is unmodified and >>mixed with the desired harmonic to give the necessary output signal which >>is then filtered to get rid of the unwanted mixing products. If that's all >>correct, as I believe it is, where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
On Sun, 28 Jul 2024 19:16:10 -0700, john larkin
<jlarkin_highland_tech> wrote:
On Sun, 28 Jul 2024 21:40:41 -0000 (UTC), Cursitor Doom >><cd999666@notformail.com> wrote:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >>>signal from the LHS is passed through a very fast diode which generates >>>harmonics from that fundamental. The signal from the RHS is unmodified and >>>mixed with the desired harmonic to give the necessary output signal which >>>is then filtered to get rid of the unwanted mixing products. If that's all >>>correct, as I believe it is, where does any *sampling* come into it?
Mixing = sampling = multiplication.
Apples = oranges = pears is an equally valid statement!
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in >><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >>>signal from the LHS is passed through a very fast diode which generates >>>harmonics from that fundamental. The signal from the RHS is unmodified >>>and mixed with the desired harmonic to give the necessary output signal >>>which is then filtered to get rid of the unwanted mixing products. If >>>that's all correct, as I believe it is, where does any *sampling* come >>>into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode
thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a
pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which
resembles other multiplier-type things once you lowpass filter the
output. That's a "synchronous detector", which we usually do in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened Cursitor >>Doom <cd999666@notformail.com> wrote in <v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. The >>>signal from the LHS is passed through a very fast diode which generates >>>harmonics from that fundamental. The signal from the RHS is unmodified and >>>mixed with the desired harmonic to give the necessary output signal which >>>is then filtered to get rid of the unwanted mixing products. If that's all >>>correct, as I believe it is, where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode
thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a
pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which
resembles other multiplier-type things once you lowpass filter the
output. That's a "synchronous detector", which we usually do in an
FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john larkin <jlarkin_highland_tech> wrote in <72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>Cursitor Doom <cd999666@notformail.com> wrote in >>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out.
The signal from the LHS is passed through a very fast diode which >>>>generates harmonics from that fundamental. The signal from the RHS is >>>>unmodified and mixed with the desired harmonic to give the necessary >>>>output signal which is then filtered to get rid of the unwanted mixing >>>>products. If that's all correct, as I believe it is, where does any >>>>*sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode
thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a
pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which
resembles other multiplier-type things once you lowpass filter the
output. That's a "synchronous detector", which we usually do in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz distorted sine wave and then a second stage tuned at 3 MHz,.. turned to
third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john larkin
<jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I think in this context, HP is using the term "sampler" to mean something which 'sniffs' a small amount of a signal for testing purposes. Like a few turns of wire around a transmission line will 'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the manner
a sampling oscilloscope works. That's what threw me. I tend to interpret things very literally. :(
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john larkin
<jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>The signal from the LHS is passed through a very fast diode which >>>>>generates harmonics from that fundamental. The signal from the RHS is >>>>>unmodified and mixed with the desired harmonic to give the necessary >>>>>output signal which is then filtered to get rid of the unwanted mixing >>>>>products. If that's all correct, as I believe it is, where does any >>>>>*sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>resembles other multiplier-type things once you lowpass filter the >>>output. That's a "synchronous detector", which we usually do in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned to
third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean something >which 'sniffs' a small amount of a signal for testing purposes. Like a few >turns of wire around a transmission line will 'sniff' a small sample of >what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the manner
a sampling oscilloscope works. That's what threw me. I tend to interpret >things very literally. :(
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>>The signal from the LHS is passed through a very fast diode which >>>>>>generates harmonics from that fundamental. The signal from the RHS >>>>>>is unmodified and mixed with the desired harmonic to give the >>>>>>necessary output signal which is then filtered to get rid of the >>>>>>unwanted mixing products. If that's all correct, as I believe it is, >>>>>>where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>resembles other multiplier-type things once you lowpass filter the >>>>output. That's a "synchronous detector", which we usually do in an >>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned
to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will
'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to >>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened Cursitor >Doom <cd999666@notformail.com> wrote in <v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>>>wrote:A the word 'mixer' in RF is not the same as a multiplier,,
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>AFAICT, there's are two signals into this thing and one signal out. >>>>>>>>The signal from the LHS is passed through a very fast diode which >>>>>>>>generates harmonics from that fundamental. The signal from the RHS >>>>>>>>is unmodified and mixed with the desired harmonic to give the >>>>>>>>necessary output signal which is then filtered to get rid of the >>>>>>>>unwanted mixing products. If that's all correct, as I believe it is, >>>>>>>>where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>>pentode. Or even a single diode. All do some flavor of multiplying. >>>>>>
Some mixers inherently multiply a signal by a square wave, which >>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals. >>>>>
Multipliers are like harmonic generating stages say you have a 1 MHz >>>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>>> to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>something which 'sniffs' a small amount of a signal for testing >>>>purposes. Like a few turns of wire around a transmission line will >>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day which >>many RF designers still use. There is a *ton* of service info on this
model online. However, I have not been able to see a *proper* schematic
for the "sampler" in the A11A5 board which is where the issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr-programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B,%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits
I will have a look at the hundreds of pages, will take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to 12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium reference)
Also build a small downmixer so it can see 2.4 GHz too
Plenty free spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif
uses this guys software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-domain.html
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>>wrote:A the word 'mixer' in RF is not the same as a multiplier,,
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>>>The signal from the LHS is passed through a very fast diode which >>>>>>>generates harmonics from that fundamental. The signal from the RHS >>>>>>>is unmodified and mixed with the desired harmonic to give the >>>>>>>necessary output signal which is then filtered to get rid of the >>>>>>>unwanted mixing products. If that's all correct, as I believe it is, >>>>>>>where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>resembles other multiplier-type things once you lowpass filter the >>>>>output. That's a "synchronous detector", which we usually do in an >>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals. >>>>
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned
to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will >>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to >>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day which
many RF designers still use. There is a *ton* of service info on this
model online. However, I have not been able to see a *proper* schematic
for the "sampler" in the A11A5 board which is where the issue is.
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happenedhp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- programming_1984_sm.pdf/download.html#dl
Cursitor Doom <cd999666@notformail.com> wrote in <v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>>pentode. Or even a single diode. All do some flavor of multiplying. >>>>>>
Some mixers inherently multiply a signal by a square wave, which >>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz >>>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>>> to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>something which 'sniffs' a small amount of a signal for testing >>>>purposes. Like a few turns of wire around a transmission line will >>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day which >>many RF designers still use. There is a *ton* of service info on this
model online. However, I have not been able to see a *proper* schematic
for the "sampler" in the A11A5 board which is where the issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/
Then trouble shooting manual part 1HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
https://xdevs.com/doc/HP_Agilent_Keysight/
Seems to have at least some circuits (just a quick look)%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B,
also has some circuits I will have a look at the hundreds of pages, will
take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,domain.html
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to
12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium
reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free
spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys
software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use
for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in >><v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1
MHz distorted sine wave and then a second stage tuned at 3 MHz,..
turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>something which 'sniffs' a small amount of a signal for testing >>>>>purposes. Like a few turns of wire around a transmission line will >>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day
which many RF designers still use. There is a *ton* of service info on >>>this model online. However, I have not been able to see a *proper* >>>schematic for the "sampler" in the A11A5 board which is where the issue >>>is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, %208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages, will >>take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to
12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium
reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free
spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you >>select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys
software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr- domain.html
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use
for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
Joe Gwinn
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened >>>Cursitor Doom <cd999666@notformail.com> wrote in >>><v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>which many RF designers still use. There is a *ton* of service info on >>>>this model online. However, I have not been able to see a *proper* >>>>schematic for the "sampler" in the A11A5 board which is where the issue >>>>is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages, will >>>take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to
12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium >>>reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free >>>spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you >>>select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys
software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr- >domain.html
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most >likely age-related and wouldn't have come to light for many years. >Fortunately there's a lot of info out there - *if* you can find it!
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john larkin
<jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>The signal from the LHS is passed through a very fast diode which >>>>>generates harmonics from that fundamental. The signal from the RHS is >>>>>unmodified and mixed with the desired harmonic to give the necessary >>>>>output signal which is then filtered to get rid of the unwanted mixing >>>>>products. If that's all correct, as I believe it is, where does any >>>>>*sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>resembles other multiplier-type things once you lowpass filter the >>>output. That's a "synchronous detector", which we usually do in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned to
third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean something >which 'sniffs' a small amount of a signal for testing purposes. Like a few >turns of wire around a transmission line will 'sniff' a small sample of >what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the manner
a sampling oscilloscope works. That's what threw me. I tend to interpret >things very literally. :(
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>> wrote:A the word 'mixer' in RF is not the same as a multiplier,,
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>>> The signal from the LHS is passed through a very fast diode which >>>>>>> generates harmonics from that fundamental. The signal from the RHS >>>>>>> is unmodified and mixed with the desired harmonic to give the
necessary output signal which is then filtered to get rid of the >>>>>>> unwanted mixing products. If that's all correct, as I believe it is, >>>>>>> where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>> thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a
pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which
resembles other multiplier-type things once you lowpass filter the
output. That's a "synchronous detector", which we usually do in an
FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals. >>>>
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned
to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will
'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to
interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day which
many RF designers still use. There is a *ton* of service info on this
model online. However, I have not been able to see a *proper* schematic
for the "sampler" in the A11A5 board which is where the issue is.
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened Cursitor >> Doom <cd999666@notformail.com> wrote in <v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>>>> wrote:A the word 'mixer' in RF is not the same as a multiplier,,
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>>>>> The signal from the LHS is passed through a very fast diode which >>>>>>>>> generates harmonics from that fundamental. The signal from the RHS >>>>>>>>> is unmodified and mixed with the desired harmonic to give the >>>>>>>>> necessary output signal which is then filtered to get rid of the >>>>>>>>> unwanted mixing products. If that's all correct, as I believe it is, >>>>>>>>> where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>>> thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>>> pentode. Or even a single diode. All do some flavor of multiplying. >>>>>>>
Some mixers inherently multiply a signal by a square wave, which >>>>>>> resembles other multiplier-type things once you lowpass filter the >>>>>>> output. That's a "synchronous detector", which we usually do in an >>>>>>> FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals. >>>>>>
Multipliers are like harmonic generating stages say you have a 1 MHz >>>>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>>>> to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will
'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to >>>>> interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day which >>> many RF designers still use. There is a *ton* of service info on this
model online. However, I have not been able to see a *proper* schematic
for the "sampler" in the A11A5 board which is where the issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr-programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B,%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits
I will have a look at the hundreds of pages, will take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to
12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium reference) >> Also build a small downmixer so it can see 2.4 GHz too
Plenty free spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you
select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif
uses this guys software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-domain.html
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
Joe Gwinn
Cursitor Doom <cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:The schematic of A11U1 might only show three diodes, the srd and two schottkys - the magic is in the physical construction. Flip chips,hi
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje
<alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal >>>>>>>> out. The signal from the LHS is passed through a very fast diode >>>>>>>> which generates harmonics from that fundamental. The signal from >>>>>>>> the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>> the necessary output signal which is then filtered to get rid of >>>>>>>> the unwanted mixing products. If that's all correct, as I believe >>>>>>>> it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant
diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing
like a pentode. Or even a single diode. All do some flavor of
multiplying.
Some mixers inherently multiply a signal by a square wave, which
resembles other multiplier-type things once you lowpass filter the >>>>>> output. That's a "synchronous detector", which we usually do in an >>>>>> FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two
signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz >>>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>>> to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will
'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to
interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day
which many RF designers still use. There is a *ton* of service info on
this model online. However, I have not been able to see a *proper*
schematic for the "sampler" in the A11A5 board which is where the issue
is.
ceramic substrate, artfully designed micro strips and what not. I doubt
that assembly is amenable to repair.
The HP8566 seems to be notorious for fiendish YTO unlock problems which
more often than not end up being trivial preset pot wiper lifts or aged capacitors in the YIG coil drivers.
On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>>The signal from the LHS is passed through a very fast diode which >>>>>>generates harmonics from that fundamental. The signal from the RHS >>>>>>is unmodified and mixed with the desired harmonic to give the >>>>>>necessary output signal which is then filtered to get rid of the >>>>>>unwanted mixing products. If that's all correct, as I believe it is, >>>>>>where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>resembles other multiplier-type things once you lowpass filter the >>>>output. That's a "synchronous detector", which we usually do in an >>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned
to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will
'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to >>interpret things very literally. :(
The sampler in the SA schematic is precisely the sort of sampler used in
a sampling scope. It contains a step-recovery diode impulse generator
and no doubt some sampling diodes.
It does have schematics, in a manner of speaking.
On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote:
On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid> >>>>>wrote:A the word 'mixer' in RF is not the same as a multiplier,,
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out. >>>>>>>The signal from the LHS is passed through a very fast diode which >>>>>>>generates harmonics from that fundamental. The signal from the RHS >>>>>>>is unmodified and mixed with the desired harmonic to give the >>>>>>>necessary output signal which is then filtered to get rid of the >>>>>>>unwanted mixing products. If that's all correct, as I believe it is, >>>>>>>where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>pentode. Or even a single diode. All do some flavor of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>resembles other multiplier-type things once you lowpass filter the >>>>>output. That's a "synchronous detector", which we usually do in an >>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two signals. >>>>
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned
to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will >>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to >>>interpret things very literally. :(
The sampler in the SA schematic is precisely the sort of sampler used in
a sampling scope. It contains a step-recovery diode impulse generator
and no doubt some sampling diodes.
How can you say that when you haven't seen the schematic? If you've been
able to find it online somewhere then kindly post a link to it here.
On Tue, 30 Jul 2024 19:21:28 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote:
On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>>pentode. Or even a single diode. All do some flavor of multiplying. >>>>>>
Some mixers inherently multiply a signal by a square wave, which >>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz >>>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>>> to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>something which 'sniffs' a small amount of a signal for testing >>>>purposes. Like a few turns of wire around a transmission line will >>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>interpret things very literally. :(
The sampler in the SA schematic is precisely the sort of sampler used
in a sampling scope. It contains a step-recovery diode impulse
generator and no doubt some sampling diodes.
How can you say that when you haven't seen the schematic? If you've been >>able to find it online somewhere then kindly post a link to it here.
You posted an excerpt from the HP manual where the sampler is described.
On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom ><cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened >>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>><v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>which many RF designers still use. There is a *ton* of service info on >>>>>this model online. However, I have not been able to see a *proper* >>>>>schematic for the "sampler" in the A11A5 board which is where the issue >>>>>is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages, will >>>>take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>>12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium >>>>reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free >>>>spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you >>>>select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys
software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr- >>domain.html
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>>for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most >>likely age-related and wouldn't have come to light for many years. >>Fortunately there's a lot of info out there - *if* you can find it!
On the lack of a schematic, I did dig into how it worked many years
ago, and as I recall it was based of some fancy abuse of a slotted >rectangular waveguide which supported various orthogonal modes - this
cannot be described by any lumped-parameter circuit.
Try this:
US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg. >Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987.
.<https://patents.google.com/patent/US4647795A>
It does have schematics, in a manner of speaking.
Joe Gwinn
On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr-
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje
<alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>> AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>> out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>> which generates harmonics from that fundamental. The signal from >>>>>>>>>>> the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>> the necessary output signal which is then filtered to get rid of >>>>>>>>>>> the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>> it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>> diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>> like a pentode. Or even a single diode. All do some flavor of >>>>>>>>> multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>> resembles other multiplier-type things once you lowpass filter the >>>>>>>>> output. That's a "synchronous detector", which we usually do in an >>>>>>>>> FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>> signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will >>>>>>> 'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>> manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>> interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day
which many RF designers still use. There is a *ton* of service info on >>>>> this model online. However, I have not been able to see a *proper*
schematic for the "sampler" in the A11A5 board which is where the issue >>>>> is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/
programming_1984_sm.pdf/download.html#dl
HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdfThen trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/
%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdfSeems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B,
domain.htmlalso has some circuits I will have a look at the hundreds of pages, will >>>> take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>> 12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium
reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free
spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you >>>> select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys
software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>> for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most
likely age-related and wouldn't have come to light for many years.
Fortunately there's a lot of info out there - *if* you can find it!
On the lack of a schematic, I did dig into how it worked many years
ago, and as I recall it was based of some fancy abuse of a slotted rectangular waveguide which supported various orthogonal modes - this
cannot be described by any lumped-parameter circuit.
Try this:
US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg. Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987.
.<https://patents.google.com/patent/US4647795A>
It does have schematics, in a manner of speaking.
Joe Gwinn
Jeroen Belleman <jeroen@nospam.please> wrote:
On 7/30/24 19:46, Joe Gwinn wrote:
On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid> >>>>> wrote:hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr-
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened >>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje
<alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>>> AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>>> out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>>> which generates harmonics from that fundamental. The signal from >>>>>>>>>>>>> the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>>> the necessary output signal which is then filtered to get rid of >>>>>>>>>>>>> the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>>>> it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>>> diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>>> like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>>> multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>>> resembles other multiplier-type things once you lowpass filter the >>>>>>>>>>> output. That's a "synchronous detector", which we usually do in an >>>>>>>>>>> FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>>> signals.
A the word 'mixer' in RF is not the same as a multiplier,, >>>>>>>>>> Multipliers are like harmonic generating stages say you have a 1 >>>>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>>> something which 'sniffs' a small amount of a signal for testing >>>>>>>>> purposes. Like a few turns of wire around a transmission line will >>>>>>>>> 'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>>> manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>>>> interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>>> which many RF designers still use. There is a *ton* of service info on >>>>>>> this model online. However, I have not been able to see a *proper* >>>>>>> schematic for the "sampler" in the A11A5 board which is where the issue >>>>>>> is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/
programming_1984_sm.pdf/download.html#dl
HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdfThen trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/
%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdfSeems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B,
also has some circuits I will have a look at the hundreds of pages, will >>>>>> take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>>>> 12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium
reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free >>>>>> spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you >>>>>> select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys >>>>>> software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr- >>>> domain.html
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>>>> for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most >>>> likely age-related and wouldn't have come to light for many years.
Fortunately there's a lot of info out there - *if* you can find it!
On the lack of a schematic, I did dig into how it worked many years
ago, and as I recall it was based of some fancy abuse of a slotted
rectangular waveguide which supported various orthogonal modes - this
cannot be described by any lumped-parameter circuit.
Try this:
US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg.
Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987.
.<https://patents.google.com/patent/US4647795A>
It does have schematics, in a manner of speaking.
Joe Gwinn
If it's Agoston's, it's a genuine time-domain short-pulse sampler,
not an attenuator pick-off.
Jeroen Belleman
Doesn’t this predate Agoston’s work?
On Tue, 30 Jul 2024 13:15:59 -0700, john larkin wrote:
On Tue, 30 Jul 2024 19:21:28 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote:
On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. AFAICT, >>>>>>>>>there's are two signals into this thing and one signal out. The >>>>>>>>>signal from the LHS is passed through a very fast diode which >>>>>>>>>generates harmonics from that fundamental. The signal from the >>>>>>>>>RHS is unmodified and mixed with the desired harmonic to give the >>>>>>>>>necessary output signal which is then filtered to get rid of the >>>>>>>>>unwanted mixing products. If that's all correct, as I believe it >>>>>>>>>is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1
MHz distorted sine wave and then a second stage tuned at 3 MHz,..
turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>something which 'sniffs' a small amount of a signal for testing >>>>>purposes. Like a few turns of wire around a transmission line will >>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>interpret things very literally. :(
The sampler in the SA schematic is precisely the sort of sampler used
in a sampling scope. It contains a step-recovery diode impulse
generator and no doubt some sampling diodes.
How can you say that when you haven't seen the schematic? If you've
been able to find it online somewhere then kindly post a link to it
here.
You posted an excerpt from the HP manual where the sampler is
described.
But you said:
"The sampler in the SA schematic is precisely the sort of sampler used
in a sampling scope."
So you must have had sight of the schematic. I'd really appreciate it if
you could post a link to it.
On 7/30/24 19:46, Joe Gwinn wrote:
On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr-
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje
<alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>> AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>> out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>> which generates harmonics from that fundamental. The signal from >>>>>>>>>>>> the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>> the necessary output signal which is then filtered to get rid of >>>>>>>>>>>> the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>>> it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>> diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>> like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>> multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>> resembles other multiplier-type things once you lowpass filter the >>>>>>>>>> output. That's a "synchronous detector", which we usually do in an >>>>>>>>>> FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>> signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>> something which 'sniffs' a small amount of a signal for testing >>>>>>>> purposes. Like a few turns of wire around a transmission line will >>>>>>>> 'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>> manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>>> interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>> which many RF designers still use. There is a *ton* of service info on >>>>>> this model online. However, I have not been able to see a *proper* >>>>>> schematic for the "sampler" in the A11A5 board which is where the issue >>>>>> is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/
programming_1984_sm.pdf/download.html#dl
HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdfThen trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/
%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdfSeems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B,
domain.htmlalso has some circuits I will have a look at the hundreds of pages, will >>>>> take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>>> 12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium
reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free
spectral display programs online for it,
I wrote my own:
https://panteltje.nl/panteltje/xpsa/index.html
it also has an 'harmonic' button to look for the next harmonic when you >>>>> select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys
software<;
http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>>> for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most >>> likely age-related and wouldn't have come to light for many years.
Fortunately there's a lot of info out there - *if* you can find it!
On the lack of a schematic, I did dig into how it worked many years
ago, and as I recall it was based of some fancy abuse of a slotted
rectangular waveguide which supported various orthogonal modes - this
cannot be described by any lumped-parameter circuit.
Try this:
US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg.
Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987.
.<https://patents.google.com/patent/US4647795A>
It does have schematics, in a manner of speaking.
Joe Gwinn
If it's Agoston's, it's a genuine time-domain short-pulse sampler,
not an attenuator pick-off.
Jeroen Belleman
On Tue, 30 Jul 2024 13:46:06 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:
On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom >><cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened >>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>><v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>>which many RF designers still use. There is a *ton* of service info on >>>>>>this model online. However, I have not been able to see a *proper* >>>>>>schematic for the "sampler" in the A11A5 board which is where the issue >>>>>>is.
OK, thank you, I will google a bit..
I got the user manual now:
< https://elektrotanya.com/> >>>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
< https://xdevs.com/doc/HP_Agilent_Keysight/> >>>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
< https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf>
also has some circuits I will have a look at the hundreds of pages, will >>>>>take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
< https://www.ebay.com/p/22032165355?iid=335019807057>
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>>>12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium >>>>>reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free >>>>>spectral display programs online for it,
I wrote my own:
<https://panteltje.nl/panteltje/xpsa/index.html>
it also has an 'harmonic' button to look for the next harmonic when you >>>>>select a carrier...
The latest version has some more stuff and runs on Raspberry Pi..
The RTL_SDR sticks can even receive GPS signals...
<https://panteltje.nl/pub/run_50_outside_2728000.gif > uses this guys >>>>> software<;
<http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-domain.html>
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>>>for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most >>>likely age-related and wouldn't have come to light for many years. >>>Fortunately there's a lot of info out there - *if* you can find it!
On the lack of a schematic, I did dig into how it worked many years
ago, and as I recall it was based of some fancy abuse of a slotted >>rectangular waveguide which supported various orthogonal modes - this >>cannot be described by any lumped-parameter circuit.
Try this:
US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg. >>Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987.
.<https://patents.google.com/patent/US4647795A>
It does have schematics, in a manner of speaking.
Joe Gwinn
I have an old HP sampling plugin that uses a machined block slotline >structure. 3 GHz bandwidth as I recall.
<https://www.dropbox.com/scl/fo/3h4fvsfdh2youfd4kuolk/AIapB4g1x0BYRNXRIrAsrO8?rlkey=q5v7llkkk6yagr2w7h4c4kq8k&dl=0>
Agoston has a patent for a similar metal-block slotline sampler, but
as far as I know Tek never manufactured it. The SD-series samplers
were hybrids.
<https://www.dropbox.com/scl/fo/dnejszdktyc70se6frcdo/AM4vWFFsXPPF4Tw2ZeEm6m8?rlkey=xm82mhqn5mnrlv3l9j0pebj29&dl=0>
On Tue, 30 Jul 2024 21:08:34 -0000 (UTC), Cursitor Doom wrote:
On Tue, 30 Jul 2024 13:15:59 -0700, john larkin wrote:
On Tue, 30 Jul 2024 19:21:28 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote:
On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. AFAICT, >>>>>>>>>>there's are two signals into this thing and one signal out. The >>>>>>>>>>signal from the LHS is passed through a very fast diode which >>>>>>>>>>generates harmonics from that fundamental. The signal from the >>>>>>>>>>RHS is unmodified and mixed with the desired harmonic to give the >>>>>>>>>>necessary output signal which is then filtered to get rid of the >>>>>>>>>>unwanted mixing products. If that's all correct, as I believe it >>>>>>>>>>is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>interpret things very literally. :(
The sampler in the SA schematic is precisely the sort of sampler used >>>>> in a sampling scope. It contains a step-recovery diode impulse
generator and no doubt some sampling diodes.
How can you say that when you haven't seen the schematic? If you've >>>>been able to find it online somewhere then kindly post a link to it >>>>here.
You posted an excerpt from the HP manual where the sampler is
described.
But you said:
"The sampler in the SA schematic is precisely the sort of sampler used
in a sampling scope."
So you must have had sight of the schematic. I'd really appreciate it if
you could post a link to it.
Also, you said the SRD was acting as an "impulse generator" when I assumed
it was simply generating harmonics to boost the M/N loop output up in
order to mix with the output of the YTO.
On Tue, 30 Jul 2024 13:31:20 -0700, john larkin
<jlarkin_highland_tech> wrote:
On Tue, 30 Jul 2024 13:46:06 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:
On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom >>><cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje <alien@comet.invalid> >>>>> wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened >>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>><v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,, >>>>>>>>>> Multipliers are like harmonic generating stages say you have a 1 >>>>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across >>>>>>>> with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>>>which many RF designers still use. There is a *ton* of service info on >>>>>>>this model online. However, I have not been able to see a *proper* >>>>>>>schematic for the "sampler" in the A11A5 board which is where the issue >>>>>>>is.
OK, thank you, I will google a bit..
I got the user manual now:
< https://elektrotanya.com/> >>>>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>>>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
< https://xdevs.com/doc/HP_Agilent_Keysight/> >>>>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
< https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>>>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf>
also has some circuits I will have a look at the hundreds of pages, will >>>>>>take some time.
I presume you have these?
Took 10 seconds to find with google
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
< https://www.ebay.com/p/22032165355?iid=335019807057>
I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>>>>12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium >>>>>>reference)
Also build a small downmixer so it can see 2.4 GHz too Plenty free >>>>>>spectral display programs online for it,
I wrote my own:
<https://panteltje.nl/panteltje/xpsa/index.html>
it also has an 'harmonic' button to look for the next harmonic when you >>>>>>select a carrier...
The latest version has some more stuff and runs on Raspberry Pi.. >>>>>>The RTL_SDR sticks can even receive GPS signals...
<https://panteltje.nl/pub/run_50_outside_2728000.gif > uses this guys >>>>>> software<;
<http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr-domain.html>
For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>>>>for my Raspberry)
and there are several audio programs with spectrum display
There are so many possibilities...
HP always put the theory notes in the HP Journal, so I'd suggest
searching there for the HP8566B, in the issues around when the
instrument was first introduced.
This analyser is well over 30 years old, so whatever's gone wrong is most >>>>likely age-related and wouldn't have come to light for many years. >>>>Fortunately there's a lot of info out there - *if* you can find it!
On the lack of a schematic, I did dig into how it worked many years
ago, and as I recall it was based of some fancy abuse of a slotted >>>rectangular waveguide which supported various orthogonal modes - this >>>cannot be described by any lumped-parameter circuit.
Try this:
US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg. >>>Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987.
.<https://patents.google.com/patent/US4647795A>
It does have schematics, in a manner of speaking.
Joe Gwinn
I have an old HP sampling plugin that uses a machined block slotline >>structure. 3 GHz bandwidth as I recall.
<https://www.dropbox.com/scl/fo/3h4fvsfdh2youfd4kuolk/AIapB4g1x0BYRNXRIrAsrO8?rlkey=q5v7llkkk6yagr2w7h4c4kq8k&dl=0>
Agoston has a patent for a similar metal-block slotline sampler, but
as far as I know Tek never manufactured it. The SD-series samplers
were hybrids.
<https://www.dropbox.com/scl/fo/dnejszdktyc70se6frcdo/AM4vWFFsXPPF4Tw2ZeEm6m8?rlkey=xm82mhqn5mnrlv3l9j0pebj29&dl=0>
I recall these pictures. I was wondering if HP copied the general
approach if not the patented design. Or licence it.
Jeroen correctly commented that "If it's Agoston's, it's a genuine >time-domain short-pulse sampler, not an attenuator pick-off."
Joe Gwinn
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode >>>>>>>thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a >>>>>>>pentode. Or even a single diode. All do some flavor of multiplying. >>>>>>>
Some mixers inherently multiply a signal by a square wave, which >>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz >>>>>> distorted sine wave and then a second stage tuned at 3 MHz,.. turned >>>>>> to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>something which 'sniffs' a small amount of a signal for testing >>>>>purposes. Like a few turns of wire around a transmission line will >>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came across
with google.
It's the HP8566B - a very well known lab-grade analyser of the day which >>>many RF designers still use. There is a *ton* of service info on this >>>model online. However, I have not been able to see a *proper* schematic >>>for the "sampler" in the A11A5 board which is where the issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages, will
take some time.
I presume you have these?
Took 10 seconds to find with google
Yes, I have all of those and more. I think altogether there are 7 very
large manuals for this analyser. However, I've not been able to find a
single actual schematic which gives component level detail of what they
call the "sampler" - and that's unusual, as they've given a great deal of >attention to providing very full service details in all other respects.
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
On Tue, 30 Jul 2024 21:58:44 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 21:08:34 -0000 (UTC), Cursitor Doom wrote:
On Tue, 30 Jul 2024 13:15:59 -0700, john larkin wrote:
On Tue, 30 Jul 2024 19:21:28 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote:
On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it >>>>>>>>>>happened Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>AFAICT,
there's are two signals into this thing and one signal out. The >>>>>>>>>>>signal from the LHS is passed through a very fast diode which >>>>>>>>>>>generates harmonics from that fundamental. The signal from the >>>>>>>>>>>RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>the necessary output signal which is then filtered to get rid >>>>>>>>>>>of the unwanted mixing products. If that's all correct, as I >>>>>>>>>>>believe it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>resembles other multiplier-type things once you lowpass filter >>>>>>>>>the output. That's a "synchronous detector", which we usually do >>>>>>>>>in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend >>>>>>>to interpret things very literally. :(
The sampler in the SA schematic is precisely the sort of sampler
used in a sampling scope. It contains a step-recovery diode impulse >>>>>> generator and no doubt some sampling diodes.
How can you say that when you haven't seen the schematic? If you've >>>>>been able to find it online somewhere then kindly post a link to it >>>>>here.
You posted an excerpt from the HP manual where the sampler is
described.
But you said:
"The sampler in the SA schematic is precisely the sort of sampler used
in a sampling scope."
So you must have had sight of the schematic. I'd really appreciate it
if you could post a link to it.
No, all I saw was the description.
Also, you said the SRD was acting as an "impulse generator" when I
assumed it was simply generating harmonics to boost the M/N loop output
up in order to mix with the output of the YTO.
They are really the same thing. An impulse train is a harmonic comb.
On a sunny day (Tue, 30 Jul 2024 15:11:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8avr7$13368$1@dont-email.me>:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it >>>>>>>>>happened Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to >>>>>>>>>>give the necessary output signal which is then filtered to get >>>>>>>>>>rid of the unwanted mixing products. If that's all correct, as I >>>>>>>>>>believe it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>manner a sampling oscilloscope works. That's what threw me. I tend >>>>>>to interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came
across with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>which many RF designers still use. There is a *ton* of service info on >>>>this model online. However, I have not been able to see a *proper* >>>>schematic for the "sampler" in the A11A5 board which is where the
issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages,
will take some time.
I presume you have these?
Took 10 seconds to find with google
Yes, I have all of those and more. I think altogether there are 7 very >>large manuals for this analyser. However, I've not been able to find a >>single actual schematic which gives component level detail of what they >>call the "sampler" - and that's unusual, as they've given a great deal
of attention to providing very full service details in all other
respects.
Will read some of it and let you know what I come up with ..
OK have flipped through all circuit diagrams in the thing.
It looks to me like a heterodyne down converter followed by a narrow
filter IF stage tuned over the whole frequency range.
No sampling on the input signal at all.
Just a RF mixer.
PLLs in the tuned oscillator that are used to scan the band.
Like an old AM shortwave radio where you turn the big tuning knob really
fast mechanically to see the amplitude of each station on the cats eye
as you tune over the whole receive spectrum.
spectrum width set by the 450 kHz or so IF filter stages in those radio days....
To get the IF narrow enough I did notice some crystal filter?, multi
stage RC filters?
Scanning the band takes time that way... horizontal deflection scope, amplitude on vertical deflection scope..
Does it have a long persistence screen?
That way you can point at any small section of the input like long wave
/ medium wave / shortwave in the old radios.
Also because I do not see any Fourier transform / computah /
computation..
That thing is from 1987? enough computah power back then for Fourier transform?
I could be wrong though, more than a 1000 pages read in... lemme see...
an hour.
Need to sleep on it and look again.
Rest is just scope trace drive and power supplies..
Its all so easy:
https://panteltje.nl/panteltje/scope_tv/index.html
HP should have added a teefee mode, but alas, analog teefee is dead in
most of the world these days.
This is more fun:
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
Use a Raspberry Pi or a PC ..
I remember when I build a frequency counter with nixy tubes and TTL and
100 kHz crystal took it to work (tube days) it blew the guys away..
Then demoed it at the local ham group connected to the local oscillator
of a shortwave receiver Explained 'subtract the IF frequency from the indicated frequency to get the real frequency'
Most radios have that now with nice LCD screens and PLL local
oscillators.... Or now even direct sampling like that SDR_RTL stuff.
I personally would dump the HP thing.. or maybe donate it to some
museum..
On Wed, 31 Jul 2024 10:54:58 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 15:11:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8avr7$13368$1@dont-email.me>:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it >>>>>>>>>>happened Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to >>>>>>>>>>>give the necessary output signal which is then filtered to get >>>>>>>>>>>rid of the unwanted mixing products. If that's all correct, as I >>>>>>>>>>>believe it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend >>>>>>>to interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came
across with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>which many RF designers still use. There is a *ton* of service info on >>>>>this model online. However, I have not been able to see a *proper* >>>>>schematic for the "sampler" in the A11A5 board which is where the >>>>>issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >>>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >>>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages,
will take some time.
I presume you have these?
Took 10 seconds to find with google
Yes, I have all of those and more. I think altogether there are 7 very >>>large manuals for this analyser. However, I've not been able to find a >>>single actual schematic which gives component level detail of what they >>>call the "sampler" - and that's unusual, as they've given a great deal
of attention to providing very full service details in all other >>>respects.
Will read some of it and let you know what I come up with ..
OK have flipped through all circuit diagrams in the thing.
It looks to me like a heterodyne down converter followed by a narrow
filter IF stage tuned over the whole frequency range.
No sampling on the input signal at all.
Just a RF mixer.
PLLs in the tuned oscillator that are used to scan the band.
Like an old AM shortwave radio where you turn the big tuning knob really
fast mechanically to see the amplitude of each station on the cats eye
as you tune over the whole receive spectrum.
spectrum width set by the 450 kHz or so IF filter stages in those radio
days....
To get the IF narrow enough I did notice some crystal filter?, multi
stage RC filters?
Scanning the band takes time that way... horizontal deflection scope,
amplitude on vertical deflection scope..
Does it have a long persistence screen?
That way you can point at any small section of the input like long wave
/ medium wave / shortwave in the old radios.
Also because I do not see any Fourier transform / computah /
computation..
That thing is from 1987? enough computah power back then for Fourier
transform?
I could be wrong though, more than a 1000 pages read in... lemme see...
an hour.
Need to sleep on it and look again.
Rest is just scope trace drive and power supplies..
Its all so easy:
https://panteltje.nl/panteltje/scope_tv/index.html
HP should have added a teefee mode, but alas, analog teefee is dead in
most of the world these days.
This is more fun:
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
Use a Raspberry Pi or a PC ..
I remember when I build a frequency counter with nixy tubes and TTL and
100 kHz crystal took it to work (tube days) it blew the guys away..
Then demoed it at the local ham group connected to the local oscillator
of a shortwave receiver Explained 'subtract the IF frequency from the
indicated frequency to get the real frequency'
Most radios have that now with nice LCD screens and PLL local
oscillators.... Or now even direct sampling like that SDR_RTL stuff.
I personally would dump the HP thing.. or maybe donate it to some
museum..
Haha! No, neither of those things are going to happen, Jan. I'm still >suffering from PTSD at having to toss a Tek 555 into a dumpster 20 years
ago.
Plus...... I've ordered *another* HP boat anchor to assist me to fix this >one! You can never have too many boat anchors (although of course, I
have). :)
On Wed, 31 Jul 2024 14:46:52 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Wed, 31 Jul 2024 10:54:58 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 15:11:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8avr7$13368$1@dont-email.me>:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened >>>>>>>>> john larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it >>>>>>>>>>>happened Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>>out. The signal from the LHS is passed through a very fast >>>>>>>>>>>>diode which generates harmonics from that fundamental. The >>>>>>>>>>>>signal from the RHS is unmodified and mixed with the desired >>>>>>>>>>>>harmonic to give the necessary output signal which is then >>>>>>>>>>>>filtered to get rid of the unwanted mixing products. If that's >>>>>>>>>>>>all correct, as I believe it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant >>>>>>>>>>thing like a pentode. Or even a single diode. All do some flavor >>>>>>>>>>of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>>resembles other multiplier-type things once you lowpass filter >>>>>>>>>>the output. That's a "synchronous detector", which we usually do >>>>>>>>>>in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>>> MHz distorted sine wave and then a second stage tuned at 3
MHz,..
turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend >>>>>>>>to interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came
across with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>>which many RF designers still use. There is a *ton* of service info >>>>>>on this model online. However, I have not been able to see a >>>>>>*proper* schematic for the "sampler" in the A11A5 board which is >>>>>>where the issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >>>>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>>>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >>>>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>>>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages,
will take some time.
I presume you have these?
Took 10 seconds to find with google
Yes, I have all of those and more. I think altogether there are 7 very >>>>large manuals for this analyser. However, I've not been able to find a >>>>single actual schematic which gives component level detail of what
they call the "sampler" - and that's unusual, as they've given a great >>>>deal of attention to providing very full service details in all other >>>>respects.
Will read some of it and let you know what I come up with ..
OK have flipped through all circuit diagrams in the thing.
It looks to me like a heterodyne down converter followed by a narrow
filter IF stage tuned over the whole frequency range.
No sampling on the input signal at all.
Just a RF mixer.
PLLs in the tuned oscillator that are used to scan the band.
Like an old AM shortwave radio where you turn the big tuning knob
really fast mechanically to see the amplitude of each station on the
cats eye as you tune over the whole receive spectrum.
spectrum width set by the 450 kHz or so IF filter stages in those
radio days....
To get the IF narrow enough I did notice some crystal filter?, multi
stage RC filters?
Scanning the band takes time that way... horizontal deflection scope,
amplitude on vertical deflection scope..
Does it have a long persistence screen?
That way you can point at any small section of the input like long
wave / medium wave / shortwave in the old radios.
Also because I do not see any Fourier transform / computah /
computation..
That thing is from 1987? enough computah power back then for Fourier
transform?
I could be wrong though, more than a 1000 pages read in... lemme
see... an hour.
Need to sleep on it and look again.
Rest is just scope trace drive and power supplies..
Its all so easy:
https://panteltje.nl/panteltje/scope_tv/index.html
HP should have added a teefee mode, but alas, analog teefee is dead in
most of the world these days.
This is more fun:
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
Use a Raspberry Pi or a PC ..
I remember when I build a frequency counter with nixy tubes and TTL
and 100 kHz crystal took it to work (tube days) it blew the guys
away.. Then demoed it at the local ham group connected to the local
oscillator of a shortwave receiver Explained 'subtract the IF
frequency from the indicated frequency to get the real frequency'
Most radios have that now with nice LCD screens and PLL local
oscillators.... Or now even direct sampling like that SDR_RTL stuff.
I personally would dump the HP thing.. or maybe donate it to some
museum..
Haha! No, neither of those things are going to happen, Jan. I'm still >>suffering from PTSD at having to toss a Tek 555 into a dumpster 20 years >>ago.
Plus...... I've ordered *another* HP boat anchor to assist me to fix
this one! You can never have too many boat anchors (although of course,
I have). :)
Those old monsters were big, heavy, and immensely complex. Not so
reliable.
Nowadays you can get a nice color digital SA with tracking generator for around $1300 from Amazon. The little handheld toys start around $60.
I think I'll order one for my new lab. Does anyone have suggestions?
There's a 1.5 GHz Rigol for $1300 and a 3.2g Siglent for $2600.
One key point will be front-end preselection/image rejection. I've found
that even the classic HPs had terrible spruious spikes, at harmonics of
the input frequency. Tek made one SA plugin that had *no*
image rejection. You had to figure it out yourself.
Those old monsters were big, heavy, and immensely complex. Not so
reliable.
Nowadays you can get a nice color digital SA with tracking generator
for around $1300 from Amazon. The little handheld toys start around
$60.
I think I'll order one for my new lab. Does anyone have suggestions?
There's a 1.5 GHz Rigol for $1300 and a 3.2g Siglent for $2600.
One key point will be front-end preselection/image rejection. I've
found that even the classic HPs had terrible spruious spikes, at
harmonics of the input frequency. Tek made one SA plugin that had *no*
image rejection. You had to figure it out yourself.
On Wed, 31 Jul 2024 10:54:58 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 15:11:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8avr7$13368$1@dont-email.me>:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>> larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it >>>>>>>>>>happened Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to >>>>>>>>>>>give the necessary output signal which is then filtered to get >>>>>>>>>>>rid of the unwanted mixing products. If that's all correct, as I >>>>>>>>>>>believe it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>>FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>> turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend >>>>>>>to interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came
across with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>which many RF designers still use. There is a *ton* of service info on >>>>>this model online. However, I have not been able to see a *proper* >>>>>schematic for the "sampler" in the A11A5 board which is where the >>>>>issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >>>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >>>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages,
will take some time.
I presume you have these?
Took 10 seconds to find with google
Yes, I have all of those and more. I think altogether there are 7 very >>>large manuals for this analyser. However, I've not been able to find a >>>single actual schematic which gives component level detail of what they >>>call the "sampler" - and that's unusual, as they've given a great deal
of attention to providing very full service details in all other >>>respects.
Will read some of it and let you know what I come up with ..
OK have flipped through all circuit diagrams in the thing.
It looks to me like a heterodyne down converter followed by a narrow
filter IF stage tuned over the whole frequency range.
No sampling on the input signal at all.
Just a RF mixer.
PLLs in the tuned oscillator that are used to scan the band.
Like an old AM shortwave radio where you turn the big tuning knob really
fast mechanically to see the amplitude of each station on the cats eye
as you tune over the whole receive spectrum.
spectrum width set by the 450 kHz or so IF filter stages in those radio
days....
To get the IF narrow enough I did notice some crystal filter?, multi
stage RC filters?
Scanning the band takes time that way... horizontal deflection scope,
amplitude on vertical deflection scope..
Does it have a long persistence screen?
That way you can point at any small section of the input like long wave
/ medium wave / shortwave in the old radios.
Also because I do not see any Fourier transform / computah /
computation..
That thing is from 1987? enough computah power back then for Fourier
transform?
I could be wrong though, more than a 1000 pages read in... lemme see...
an hour.
Need to sleep on it and look again.
Rest is just scope trace drive and power supplies..
Its all so easy:
https://panteltje.nl/panteltje/scope_tv/index.html
HP should have added a teefee mode, but alas, analog teefee is dead in
most of the world these days.
This is more fun:
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
Use a Raspberry Pi or a PC ..
I remember when I build a frequency counter with nixy tubes and TTL and
100 kHz crystal took it to work (tube days) it blew the guys away..
Then demoed it at the local ham group connected to the local oscillator
of a shortwave receiver Explained 'subtract the IF frequency from the
indicated frequency to get the real frequency'
Most radios have that now with nice LCD screens and PLL local
oscillators.... Or now even direct sampling like that SDR_RTL stuff.
I personally would dump the HP thing.. or maybe donate it to some
museum..
Haha! No, neither of those things are going to happen, Jan. I'm still >suffering from PTSD at having to toss a Tek 555 into a dumpster 20 years
ago.
Plus...... I've ordered *another* HP boat anchor to assist me to fix this >one! You can never have too many boat anchors (although of course, I
have). :)
On a sunny day (Wed, 31 Jul 2024 14:46:52 -0000 (UTC)) it happenedAPC_UPS_ES700_waveform_25W_edison_bulb_load_IMG_0270.JPG
Cursitor Doom <cd999666@notformail.com> wrote in <v8dios$1kovj$1@dont-email.me>:
On Wed, 31 Jul 2024 10:54:58 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 15:11:35 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8avr7$13368$1@dont-email.me>:
On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8aiaf$10lqo$1@dont-email.me>:
On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote:
On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
<v8a9vr$v9r2$1@dont-email.me>:
On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened >>>>>>>>> john larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>>><alien@comet.invalid> wrote:
On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it >>>>>>>>>>>happened Cursitor Doom <cd999666@notformail.com> wrote in >>>>>>>>>>><v86dsp$3n74$1@dont-email.me>:
I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>>out. The signal from the LHS is passed through a very fast >>>>>>>>>>>>diode which generates harmonics from that fundamental. The >>>>>>>>>>>>signal from the RHS is unmodified and mixed with the desired >>>>>>>>>>>>harmonic to give the necessary output signal which is then >>>>>>>>>>>>filtered to get rid of the unwanted mixing products. If that's >>>>>>>>>>>>all correct, as I believe it is,
where does any *sampling* come into it?
A 'sampler' is fact a non-linear mixer.
In the audio world, a "mixer" is a linear summer.
In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant >>>>>>>>>>thing like a pentode. Or even a single diode. All do some flavor >>>>>>>>>>of multiplying.
Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>>resembles other multiplier-type things once you lowpass filter >>>>>>>>>>the output. That's a "synchronous detector", which we usually do >>>>>>>>>>in an FPGA.
A sampler is a signal multiplier too.
These are all variations on the basic idea of multiplying two >>>>>>>>>>signals.
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 >>>>>>>>> MHz distorted sine wave and then a second stage tuned at 3
MHz,..
turned to third harmonic.
mamamatical speaking RF mixing is indeed multiplication.
Like Shakepierce once said:
"What's in a name..." CocaCola wihout coke
I think in this context, HP is using the term "sampler" to mean >>>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>>'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend >>>>>>>>to interpret things very literally. :(
Would be nice to see a real circuit diagram of that thing.
What is the model / type number?
I am curious.
So far I have been able to find circuits for most stuff I came
across with google.
It's the HP8566B - a very well known lab-grade analyser of the day >>>>>>which many RF designers still use. There is a *ton* of service info >>>>>>on this model online. However, I have not been able to see a >>>>>>*proper* schematic for the "sampler" in the A11A5 board which is >>>>>>where the issue is.
OK, thank you, I will google a bit..
I got the user manual now:
https://elektrotanya.com/ >>>>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>>>programming_1984_sm.pdf/download.html#dl
Then trouble shooting manual part 1
https://xdevs.com/doc/HP_Agilent_Keysight/ >>>>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf
Seems to have at least some circuits (just a quick look)
and part 2
https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>>>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf
also has some circuits I will have a look at the hundreds of pages,
will take some time.
I presume you have these?
Took 10 seconds to find with google
Yes, I have all of those and more. I think altogether there are 7 very >>>>large manuals for this analyser. However, I've not been able to find a >>>>single actual schematic which gives component level detail of what
they call the "sampler" - and that's unusual, as they've given a great >>>>deal of attention to providing very full service details in all other >>>>respects.
Will read some of it and let you know what I come up with ..
OK have flipped through all circuit diagrams in the thing.
It looks to me like a heterodyne down converter followed by a narrow
filter IF stage tuned over the whole frequency range.
No sampling on the input signal at all.
Just a RF mixer.
PLLs in the tuned oscillator that are used to scan the band.
Like an old AM shortwave radio where you turn the big tuning knob
really fast mechanically to see the amplitude of each station on the
cats eye as you tune over the whole receive spectrum.
spectrum width set by the 450 kHz or so IF filter stages in those
radio days....
To get the IF narrow enough I did notice some crystal filter?, multi
stage RC filters?
Scanning the band takes time that way... horizontal deflection scope,
amplitude on vertical deflection scope..
Does it have a long persistence screen?
That way you can point at any small section of the input like long
wave / medium wave / shortwave in the old radios.
Also because I do not see any Fourier transform / computah /
computation..
That thing is from 1987? enough computah power back then for Fourier
transform?
I could be wrong though, more than a 1000 pages read in... lemme
see... an hour.
Need to sleep on it and look again.
Rest is just scope trace drive and power supplies..
Its all so easy:
https://panteltje.nl/panteltje/scope_tv/index.html
HP should have added a teefee mode, but alas, analog teefee is dead in
most of the world these days.
This is more fun:
OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so,
https://www.ebay.com/p/22032165355?iid=335019807057
Use a Raspberry Pi or a PC ..
I remember when I build a frequency counter with nixy tubes and TTL
and 100 kHz crystal took it to work (tube days) it blew the guys
away.. Then demoed it at the local ham group connected to the local
oscillator of a shortwave receiver Explained 'subtract the IF
frequency from the indicated frequency to get the real frequency'
Most radios have that now with nice LCD screens and PLL local
oscillators.... Or now even direct sampling like that SDR_RTL stuff.
I personally would dump the HP thing.. or maybe donate it to some
museum..
Haha! No, neither of those things are going to happen, Jan. I'm still >>suffering from PTSD at having to toss a Tek 555 into a dumpster 20 years >>ago.
Plus...... I've ordered *another* HP boat anchor to assist me to fix
this one! You can never have too many boat anchors (although of course,
I have). :)
Yes, the Tek 555
https://w140.com/tekwiki/wiki/555
I likely used that one in those early sixties :-)
Keep it, good analog scopes are rare...
I still use my Trio-CS1562 analog scope:
https://panteltje.nl/pub/
it has thousands of hours, was on all day in my TV repair shop..
But space is always a problem, I have located many times, other
countries, donated everything, start new.
Same for old cars I have driven..
Citroen 2CV, Peugeot 404 station, Ford Mustang V8, some memories...
Why did you dump the Tek?
Those are easy to repair.
...
I moved overseas and couldn't hold on to everything, sadly. Didn't have
time to find a museum either.
On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8fgt4$231a4$1@dont-email.me>:
...
I moved overseas and couldn't hold on to everything, sadly. Didn't have >>time to find a museum either.
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a
scope,
supply voltages.
Likely source of damage is the input stage (may have been overloaded,
manual shows strict limits)
So, put some 100 MHz or so signal on the input, check with a scope if it reaches the first mixer stage check if something comes out of that mixer stage.
If not check if the local oscillator signal is present at the mixer
stage if all OK go for the next mixer,
If all OK check if the sweep generator works so the local oscillator is actually sweeped,
check if any signal in the (20 MHz or so?) first IF stages,
basically follow the signal path.
With all the boat anchors you have 'floating??' about those measurements should be easy.
All OK so far and display scope working at least you should see a trace
with something on it
Need more info on what the problem is, should not take more than a hour
that way.
If something with the other electronics.. have not looked at it much.
On Fri, 02 Aug 2024 05:11:43 GMT, Jan Panteltje wrote:
On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8fgt4$231a4$1@dont-email.me>:
...
I moved overseas and couldn't hold on to everything, sadly. Didn't have >>>time to find a museum either.
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a
scope,
supply voltages.
Yes, first thing I did. And replaced any suspect caps.
Likely source of damage is the input stage (may have been overloaded,
manual shows strict limits)
No, the input stage is fine. I can see all the local FM stations at their >expected strength levels - but they appear to be about 20Mhz lower than
they are!
So, put some 100 MHz or so signal on the input, check with a scope if it
reaches the first mixer stage check if something comes out of that mixer
stage.
If not check if the local oscillator signal is present at the mixer
stage if all OK go for the next mixer,
If all OK check if the sweep generator works so the local oscillator is
actually sweeped,
check if any signal in the (20 MHz or so?) first IF stages,
basically follow the signal path.
With all the boat anchors you have 'floating??' about those measurements
should be easy.
All OK so far and display scope working at least you should see a trace
with something on it
Need more info on what the problem is, should not take more than a hour
that way.
If something with the other electronics.. have not looked at it much.
Self-diagnostics have localised the fault to within the YTO loop and my >subsequent investigations have narrowed down this issue with the 'greater >"sampler" stage' putting out garbage. As I said further up the thread,
either there's an issue with the 'sampler' itself or it's just doing its
best with faulty input signals: garbage in/garbage out.
There are 3 inputs to the section: fM/N, f20/30 and fYTO. All those
signals are present and their power levels are fine. But I need to ensure >their frequencies correspond to the charts provided in the manual and the >relevant derivation formulas. If not, the loop has no chance to lock.
My biggest problem is finding the time to fit it in!
On a sunny day (Fri, 2 Aug 2024 10:09:24 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8ib8k$2p2d8$1@dont-email.me>:
On Fri, 02 Aug 2024 05:11:43 GMT, Jan Panteltje wrote:
On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8fgt4$231a4$1@dont-email.me>:
...
I moved overseas and couldn't hold on to everything, sadly. Didn't
have time to find a museum either.
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a
scope,
supply voltages.
Yes, first thing I did. And replaced any suspect caps.
Likely source of damage is the input stage (may have been overloaded,
manual shows strict limits)
No, the input stage is fine. I can see all the local FM stations at
their expected strength levels - but they appear to be about 20Mhz lower >>than they are!
The 'about' 20 MHz is susicous, as the IF is 21.4 MHz.
Looks almost like a problem with the calibration On page 12 of the
manual I see an internal reference output,
is that 10 MHz correct?
What happens when yu feed in 10 MHz from an other source?
quote from that page:
To lock the spectrum analyzer to an external frequency reference, set
the FREQ REFERENCE Analyzer performance will be degraded unless
frequency reference phase noise and spurious sign dBc single sideband
(1 Hz) referred to 10 MHz at a 100 Hz to 10 kHz offset. To lock
another spect the spectrum analyzer internal frequency reference, set
the FREQ REFERENCE switch to INT
So, put some 100 MHz or so signal on the input, check with a scope if
it reaches the first mixer stage check if something comes out of that
mixer stage.
If not check if the local oscillator signal is present at the mixer
stage if all OK go for the next mixer,
If all OK check if the sweep generator works so the local oscillator
is actually sweeped,
check if any signal in the (20 MHz or so?) first IF stages,
basically follow the signal path.
With all the boat anchors you have 'floating??' about those
measurements should be easy.
All OK so far and display scope working at least you should see a
trace with something on it
Need more info on what the problem is, should not take more than a
hour that way.
If something with the other electronics.. have not looked at it much.
Self-diagnostics have localised the fault to within the YTO loop and my >>subsequent investigations have narrowed down this issue with the
'greater "sampler" stage' putting out garbage. As I said further up the >>thread, either there's an issue with the 'sampler' itself or it's just >>doing its best with faulty input signals: garbage in/garbage out.
There are 3 inputs to the section: fM/N, f20/30 and fYTO. All those
signals are present and their power levels are fine. But I need to
ensure their frequencies correspond to the charts provided in the manual >>and the relevant derivation formulas. If not, the loop has no chance to >>lock.
My biggest problem is finding the time to fit it in!
OK, we will wait and see.
If all else fails, this was fun to create:
https://panteltje.nl/panteltje/pic/scope_pic/
https://panteltje.nl/panteltje/pic/scope_pic/screen_dump2.txt
On a sunny day (Fri, 2 Aug 2024 10:09:24 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8ib8k$2p2d8$1@dont-email.me>:
On Fri, 02 Aug 2024 05:11:43 GMT, Jan Panteltje wrote:
On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8fgt4$231a4$1@dont-email.me>:
...
I moved overseas and couldn't hold on to everything, sadly. Didn't
have time to find a museum either.
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a
scope,
supply voltages.
Yes, first thing I did. And replaced any suspect caps.
Likely source of damage is the input stage (may have been overloaded,
manual shows strict limits)
No, the input stage is fine. I can see all the local FM stations at
their expected strength levels - but they appear to be about 20Mhz lower >>than they are!
The 'about' 20 MHz is susicous, as the IF is 21.4 MHz.
Looks almost like a problem with the calibration On page 12 of the
manual I see an internal reference output,
is that 10 MHz correct?
What happens when yu feed in 10 MHz from an other source?
quote from that page:
To lock the spectrum analyzer to an external frequency reference, set
the FREQ REFERENCE Analyzer performance will be degraded unless
frequency reference phase noise and spurious sign dBc single sideband
(1 Hz) referred to 10 MHz at a 100 Hz to 10 kHz offset. To lock
another spect the spectrum analyzer internal frequency reference, set
the FREQ REFERENCE switch to INT
On Fri, 02 Aug 2024 12:02:43 GMT, Jan Panteltje wrote:
On a sunny day (Fri, 2 Aug 2024 10:09:24 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8ib8k$2p2d8$1@dont-email.me>:
On Fri, 02 Aug 2024 05:11:43 GMT, Jan Panteltje wrote:
On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8fgt4$231a4$1@dont-email.me>:
...
I moved overseas and couldn't hold on to everything, sadly. Didn't >>>>>have time to find a museum either.
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a
scope,
supply voltages.
Yes, first thing I did. And replaced any suspect caps.
Likely source of damage is the input stage (may have been overloaded,
manual shows strict limits)
No, the input stage is fine. I can see all the local FM stations at
their expected strength levels - but they appear to be about 20Mhz lower >>>than they are!
The 'about' 20 MHz is susicous, as the IF is 21.4 MHz.
There are several IFs, none of which none are 21.4Mhz according to the
notes in the text. They state the IF changes according to band, so it's >3621.4Mhz for band 0, -321.4Mhz for band 1 and +321.4Mhz for bands 2, 3
and 4.
Looks almost like a problem with the calibration On page 12 of the
manual I see an internal reference output,
is that 10 MHz correct?
Yes.
What happens when yu feed in 10 MHz from an other source?
What's your thinking in that suggestion? What difference could it make?
quote from that page:
To lock the spectrum analyzer to an external frequency reference, set
the FREQ REFERENCE Analyzer performance will be degraded unless
frequency reference phase noise and spurious sign dBc single sideband
(1 Hz) referred to 10 MHz at a 100 Hz to 10 kHz offset. To lock
another spect the spectrum analyzer internal frequency reference, set
the FREQ REFERENCE switch to INT
Well, I've just wasted several more futile hours trying to make sense of
the figures given in the manuals. This thing is a *bitch* it is *so* >complicated. I've never had to deal with something of this nature before
in all my decades in the hobby. Much of the problem is having to rely on
PDF manuals and HP having spread the relevant information over several >different manuals covering thousands of pages. Nice work, HP!
On a sunny day (Fri, 2 Aug 2024 16:08:38 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8j0a6$2t2o7$2@dont-email.me>:
On Fri, 02 Aug 2024 12:02:43 GMT, Jan Panteltje wrote:
On a sunny day (Fri, 2 Aug 2024 10:09:24 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8ib8k$2p2d8$1@dont-email.me>:
On Fri, 02 Aug 2024 05:11:43 GMT, Jan Panteltje wrote:
On a sunny day (Thu, 1 Aug 2024 08:27:16 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v8fgt4$231a4$1@dont-email.me>:
...
I moved overseas and couldn't hold on to everything, sadly. Didn't >>>>>>have time to find a museum either.
As to repair / fault finding of that thing we were talking about,
I dunno what the symptoms are?
But after letting the 100 pages or so sink in in my brain:
Like somebody mentioned, check power supply (caps) for ripple with a >>>>> scope,
supply voltages.
Yes, first thing I did. And replaced any suspect caps.
Likely source of damage is the input stage (may have been
overloaded,
manual shows strict limits)
No, the input stage is fine. I can see all the local FM stations at >>>>their expected strength levels - but they appear to be about 20Mhz >>>>lower than they are!
The 'about' 20 MHz is susicous, as the IF is 21.4 MHz.
There are several IFs, none of which none are 21.4Mhz according to the >>notes in the text. They state the IF changes according to band, so it's >>3621.4Mhz for band 0, -321.4Mhz for band 1 and +321.4Mhz for bands 2, 3
and 4.
Page 10 of the manual, quote:
rear panel IF outputs
21.4 MHz IF Output
Looks almost like a problem with the calibration On page 12 of the
manual I see an internal reference output,
is that 10 MHz correct?
Yes.
What happens when yu feed in 10 MHz from an other source?
What's your thinking in that suggestion? What difference could it make?
quote from that page:
To lock the spectrum analyzer to an external frequency reference,
set the FREQ REFERENCE Analyzer performance will be degraded unless
frequency reference phase noise and spurious sign dBc single
sideband (1 Hz) referred to 10 MHz at a 100 Hz to 10 kHz offset. To
lock another spect the spectrum analyzer internal frequency
reference, set the FREQ REFERENCE switch to INT
Well, I've just wasted several more futile hours trying to make sense of >>the figures given in the manuals. This thing is a *bitch* it is *so* >>complicated. I've never had to deal with something of this nature before
in all my decades in the hobby. Much of the problem is having to rely on >>PDF manuals and HP having spread the relevant information over several >>different manuals covering thousands of pages. Nice work, HP!
I agree, in broadcasting we demanded full circuit diagrams and support
from any manufacturer that we had equipment from.
And spare parts too..
Else no buy I remember going to an Ampex training for 3 weeks in Germany
for their latest video tape recorders coming back with several kg of schematics and papers.
That HP documentation is crap, the drawings suck, looks to me they are
very hard trying to hide how it really works,
or the one who 'painted' it had no clue, or both.
It would never have been accepted by us.
But that HP stuff is simple compared to what was around in a studio.
A simple block diagram would be a good idea.
But they do not even know how to draw a signal path, using arrows
for connectors, crap.
Anyways, just use you shortwave radio, or soundcard, or better even a
rtl_sdr stick.
Using the SSB mode in shortwave with a decent modern radio, like my
Tecsun portable allows you to tune to a few Hz (zero carrier beep).
Do you have a boat? Anchors are useful.
There are several IFs, none of which none are 21.4Mhz according to the >>>notes in the text. They state the IF changes according to band, so it's >>>3621.4Mhz for band 0, -321.4Mhz for band 1 and +321.4Mhz for bands 2, 3 >>>and 4.
Page 10 of the manual, quote:
rear panel IF outputs
21.4 MHz IF Output
Wow! What a lot of IFs!
On a sunny day (Sat, 3 Aug 2024 11:27:15 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in <v8l46j$3e34d$1@dont-email.me>:
There are several IFs, none of which none are 21.4Mhz according to the >>>>notes in the text. They state the IF changes according to band, so
it's 3621.4Mhz for band 0, -321.4Mhz for band 1 and +321.4Mhz for
bands 2, 3 and 4.
Page 10 of the manual, quote:
rear panel IF outputs
21.4 MHz IF Output
Wow! What a lot of IFs!
In
HP_8566B_troubleshooting_and_repair_1.pdf
On page 55 see the 24.1 MHz originating from block A4A8A1
then pasing through a gain control block A4A5,
On page 57 you see it being processed
selectable bandwidth control A4A4 log amplifer with filters A4A3 log
detector A2A2
and then to the recorder outputs (top left page 55)
The control part 'A4A9 IF control'
selects what you want to see.
So it seems to me the 24.1 MHz is the final filter?
It _is_ possible the graticule display is wrong not the display it
self...
wild guess though, would need to measure some stuff.
Or maybe one of the PLL loops is locked at the wrong frequency.
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