• RF Metrology

    From Cursitor Doom@21:1/5 to All on Sun Sep 29 18:14:53 2024
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton.
    Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Cursitor Doom on Sun Sep 29 17:39:38 2024
    Cursitor Doom <cd@notformail.com> wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.


    Hard to tell. How big are the whoopdedoos, and roughly where?

    Posting a screenshot would help.

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Sun Sep 29 10:56:36 2024
    On Sun, 29 Sep 2024 18:14:53 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    What specific tiny SA did you buy? How's the image rejection?

    Connectors can cause passive harmonic and IM distortion. That's a big
    deal in cell phone towers.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to Cursitor Doom on Sun Sep 29 20:02:04 2024
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to jrwalliker@gmail.com on Sun Sep 29 20:47:39 2024
    On Sun, 29 Sep 2024 19:57:34 +0100, John R Walliker
    <jrwalliker@gmail.com> wrote:

    On 29/09/2024 19:02, Jeroen Belleman wrote:
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton.
    Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    I have seen transmission (S21) losses of around 1dB at about 1.2GHz
    just from failing to tighten an N connector sufficiently.
    We do need to know the magnitude and frequency of the problem in
    order to give helpful comments!
    John

    Not really. If you just think of it as a slight impedance mismatch in
    the cable between the SA and the signal generator. However, this model
    has the facility to be able to save files of the screen display
    (although I very much doubt it'll save a real-time video of the
    sweep).
    And John - it's the 'Ultra' version. I already had the base model and
    this is a worthwhile upgrade.
    Jeroen - it's more a problem of available time!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to John R Walliker on Sun Sep 29 22:08:25 2024
    On 9/29/24 20:57, John R Walliker wrote:
    On 29/09/2024 19:02, Jeroen Belleman wrote:
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    [...] Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    I have seen transmission (S21) losses of around 1dB at about 1.2GHz
    just from failing to tighten an N connector sufficiently.
    We do need to know the magnitude and frequency of the problem in
    order to give helpful comments!
    John


    I collected some TDR traces of various connectors, adapters and
    terminators a few years ago: <https://cern.ch/jeroen/connectorTDR>.

    There were a few surprises. I was taken aback by the poor results
    for H+S BNC and LEMO-00. For BNCs, Radiall is better than H+S, but
    for N-connectors, it's the reverse.

    After having seen what LEMO-00 hardware did to my signals, I was
    pleasantly surprised by the performance of SMC.

    SMA was the best I had around, hands down, no surprises there.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Sun Sep 29 14:06:23 2024
    On Sun, 29 Sep 2024 20:47:39 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 29 Sep 2024 19:57:34 +0100, John R Walliker
    <jrwalliker@gmail.com> wrote:

    On 29/09/2024 19:02, Jeroen Belleman wrote:
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the >>>> price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>>> Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to >>>> SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor >>>> with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    I have seen transmission (S21) losses of around 1dB at about 1.2GHz
    just from failing to tighten an N connector sufficiently.
    We do need to know the magnitude and frequency of the problem in
    order to give helpful comments!
    John

    Not really. If you just think of it as a slight impedance mismatch in
    the cable between the SA and the signal generator. However, this model
    has the facility to be able to save files of the screen display
    (although I very much doubt it'll save a real-time video of the
    sweep).
    And John - it's the 'Ultra' version. I already had the base model and
    this is a worthwhile upgrade.

    Ultra what? Got a link?



    Jeroen - it's more a problem of available time!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to jeroen@nospam.please on Sun Sep 29 14:21:51 2024
    On Sun, 29 Sep 2024 22:08:25 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 9/29/24 20:57, John R Walliker wrote:
    On 29/09/2024 19:02, Jeroen Belleman wrote:
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    [...] Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor >>>> with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    I have seen transmission (S21) losses of around 1dB at about 1.2GHz
    just from failing to tighten an N connector sufficiently.
    We do need to know the magnitude and frequency of the problem in
    order to give helpful comments!
    John


    I collected some TDR traces of various connectors, adapters and
    terminators a few years ago: <https://cern.ch/jeroen/connectorTDR>.

    There were a few surprises. I was taken aback by the poor results
    for H+S BNC and LEMO-00. For BNCs, Radiall is better than H+S, but
    for N-connectors, it's the reverse.

    After having seen what LEMO-00 hardware did to my signals, I was
    pleasantly surprised by the performance of SMC.

    SMA was the best I had around, hands down, no surprises there.

    Jeroen Belleman

    SMBs are surprisingly good, and easier to use.

    Shining Star makes nice, crazy cheap, edge-launch SMAs and SMBs.

    https://www.dropbox.com/scl/fi/x8w5izvfvg87bit10vty4/SS_SMB_Edge.JPG?rlkey=8xsf1wlw73wopi9vlf0slh52g&raw=1

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to john larkin on Sun Sep 29 22:52:24 2024
    On Sun, 29 Sep 2024 14:06:23 -0700, john larkin <JL@gct.com> wrote:

    On Sun, 29 Sep 2024 20:47:39 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 29 Sep 2024 19:57:34 +0100, John R Walliker
    <jrwalliker@gmail.com> wrote:

    On 29/09/2024 19:02, Jeroen Belleman wrote:
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time >>>>> testing it today. I have to say it's amazing what they've done for the >>>>> price. I mean, truly amazing. I do have two other 'proper' lab-grade >>>>> RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>>>> Anyway, to get back to the point of this post, having checked out the >>>>> TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before >>>>> which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to >>>>> this question anyway. "So what is the fucking question, CD??" I hear >>>>> you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator >>>>> and I'm seeing the displayed amplitude vary as it sweeps through the >>>>> range. But this only happens when I'm using a cheap, Chinese N-type to >>>>> SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor >>>>> with but it's a bit of an effort to do. It would seem like the SA is >>>>> showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    I have seen transmission (S21) losses of around 1dB at about 1.2GHz
    just from failing to tighten an N connector sufficiently.
    We do need to know the magnitude and frequency of the problem in
    order to give helpful comments!
    John

    Not really. If you just think of it as a slight impedance mismatch in
    the cable between the SA and the signal generator. However, this model
    has the facility to be able to save files of the screen display
    (although I very much doubt it'll save a real-time video of the
    sweep).
    And John - it's the 'Ultra' version. I already had the base model and
    this is a worthwhile upgrade.

    Ultra what? Got a link?

    https://www.ebay.com/itm/175723143799?_skw=tinysa+ultra&itmmeta=01J8ZW7WN5M0M79EM3Q420PN8Y&hash=item28e9ea6277:g:L7YAAOSwFYRkKqmj&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKlhXFuXmQPE8sSyIsULHZulooxzc4gNz7U4TcBY3Sv61MR%
    2BDICcTba8iosmDQ3okfdfPjKba2gtEcdGz3%2BWFX0qi14UOtwHmp5WA74Xmg8eJ6jW0P87d1%2B7qeg7QfphkdVj9CwPDGgfbsLN7S9yjFrpNaYPEw6zAR2e2Q1EDec3MmOeWyKRwEGMVQhHzAA0fRJXHUzJFXntq%2BjZ1HaWUDhRgGAjemjF2ijMX40otlXqvyN3egM7qIKhZFdiwThOhJYErixq4dWjJIg9Yi8Xeo%
    2BHWJsTSb8onmWlwwHRqYdClQ%3D%3D%7Ctkp%3ABFBM1sqf_Mdk

    (sorry, no time to use tinyurl at the moment!)



    Jeroen - it's more a problem of available time!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jan Panteltje@21:1/5 to cd@notformail.com on Mon Sep 30 05:40:39 2024
    On a sunny day (Sun, 29 Sep 2024 18:14:53 +0100) it happened Cursitor Doom <cd@notformail.com> wrote in <mu1jfjtd6521pp9nb0kubcorkkkdh20gu3@4ax.com>:

    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    I duuno, do not have that thing,
    but reflections in cable + connector could create dips and mountains?
    That is quite a sweep width!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jan Panteltje@21:1/5 to cd@notformail.com on Mon Sep 30 06:00:14 2024
    On a sunny day (Sun, 29 Sep 2024 22:52:24 +0100) it happened Cursitor Doom <cd@notformail.com> wrote in <1vijfjd186gmgjn6dbf93v4ehv3v1ts7pt@4ax.com>:

    On Sun, 29 Sep 2024 14:06:23 -0700, john larkin <JL@gct.com> wrote:

    On Sun, 29 Sep 2024 20:47:39 +0100, Cursitor Doom <cd@notformail.com> >>wrote:

    On Sun, 29 Sep 2024 19:57:34 +0100, John R Walliker >>><jrwalliker@gmail.com> wrote:

    On 29/09/2024 19:02, Jeroen Belleman wrote:
    On 9/29/24 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time >>>>>> testing it today. I have to say it's amazing what they've done for the >>>>>> price. I mean, truly amazing. I do have two other 'proper' lab-grade >>>>>> RF spectrum analyzers, but I think I'm going to be mostly using the >>>>>> TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>>>>> Anyway, to get back to the point of this post, having checked out the >>>>>> TSA and establishing I didn't buy one of the fake versions that are >>>>>> out there, I turned my attention to my mid-level RF SA, an HP who's >>>>>> model number escapes me (not the 8566B I've posted here about before >>>>>> which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to >>>>>> this question anyway. "So what is the fucking question, CD??" I hear >>>>>> you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep >>>>>> from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator >>>>>> and I'm seeing the displayed amplitude vary as it sweeps through the >>>>>> range. But this only happens when I'm using a cheap, Chinese N-type to >>>>>> SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could >>>>>> cause such an effect? I do have a VNA I could characterize the adaptor >>>>>> with but it's a bit of an effort to do. It would seem like the SA is >>>>>> showing the adaptor's shortcomings in the frequency domain. But is >>>>>> that a feasible hypothesis?

    Your pal,

    CD.

    Aren't we getting a teensy bit lazy?

    Jeroen Belleman

    I have seen transmission (S21) losses of around 1dB at about 1.2GHz >>>>just from failing to tighten an N connector sufficiently.
    We do need to know the magnitude and frequency of the problem in
    order to give helpful comments!
    John

    Not really. If you just think of it as a slight impedance mismatch in
    the cable between the SA and the signal generator. However, this model >>>has the facility to be able to save files of the screen display
    (although I very much doubt it'll save a real-time video of the
    sweep).
    And John - it's the 'Ultra' version. I already had the base model and >>>this is a worthwhile upgrade.

    Ultra what? Got a link?

    Mr doom, just cut theURL after the item number, like this: https://www.ebay.com/itm/175723143799


    It is a nice box, but I stay with my RTL_SDR sticks, low freqwuency converter I have.
    For that 160 dollies I have 160 / 31 = 5 of these:
    https://www.ebay.com/itm/201773887159?

    I have 2 of these, but older models, running 24/7 on raspberries:
    https://www.ebay.com/itm/284834935943
    mine are 1 ppm, this seller claims .5 ppm

    And wrote my own spectrum analyzer for it:
    latest, now lso runs on raspberry:
    https://panteltje.nl/pub/xpsa-0.7.gif

    Older version can be downloaded:
    https://panteltje.nl/panteltje/xpsa/index.html

    website needs updating..

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to All on Mon Sep 30 10:58:06 2024
    On Mon, 30 Sep 2024 05:40:39 GMT, Jan Panteltje <alien@comet.invalid>
    wrote:

    On a sunny day (Sun, 29 Sep 2024 18:14:53 +0100) it happened Cursitor Doom ><cd@notformail.com> wrote in <mu1jfjtd6521pp9nb0kubcorkkkdh20gu3@4ax.com>:

    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time >>testing it today. I have to say it's amazing what they've done for the >>price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is >>showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    I duuno, do not have that thing,
    but reflections in cable + connector could create dips and mountains?
    That is quite a sweep width!


    Yes! That is what I believe is happening. Nothing much occurs between
    1Mhz and 100Mhz, but it becomes more and more apparent as I go from
    1Ghz to 2Ghz, 2 to 3, 3 to 4 and so on - as does the attenuation. You
    can't expect miracles from cheap Chinese crap, but even crap works
    well up to high VHF/low UHF.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Robert Roland@21:1/5 to john larkin on Mon Sep 30 12:22:44 2024
    On Sun, 29 Sep 2024 14:06:23 -0700, john larkin <JL@gct.com> wrote:

    Ultra what? Got a link?

    It has its own home page:

    https://tinysa.org/
    --
    RoRo

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Klaus Vestergaard Kragelund@21:1/5 to Cursitor Doom on Sun Oct 6 17:46:02 2024
    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to klauskvik@hotmail.com on Sun Oct 6 17:49:00 2024
    On Sun, 6 Oct 2024 17:46:02 +0200, Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton.
    Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s


    Very precient of you, Klaus. I was just about to ask about others'
    experiences of cheap Chinese RF connectors. I'm reluctant to hook them
    up to my expensive Western analyzers in case they get damaged by poor
    fit or some such issue. I have to say, though, that the only issues
    I've heard about in this regard are damage to the Chinese connectors'
    center pins (being pushed in) during insertion. I could live with
    that, so long as my expensive test equipment remains unharmed.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to klauskvik@hotmail.com on Sun Oct 6 10:26:20 2024
    On Sun, 6 Oct 2024 17:46:02 +0200, Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton.
    Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s


    I solved a billion-dollar showstopper last year. Some country started
    demanding that some expensive semi fab gear be EMI tested, and our
    units failed. After great hassle we traced it to bad ground crimps on
    shielded CAT5 cables that our customer bought cheap.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to john larkin on Sun Oct 6 19:44:23 2024
    On 10/6/24 19:26, john larkin wrote:
    On Sun, 6 Oct 2024 17:46:02 +0200, Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the
    price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton.
    Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to
    SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor
    with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s


    I solved a billion-dollar showstopper last year. Some country started demanding that some expensive semi fab gear be EMI tested, and our
    units failed. After great hassle we traced it to bad ground crimps on shielded CAT5 cables that our customer bought cheap.

    I bought a set of phase-matched cables from Taiwanese company
    JYEBAO because my usual supplier Huber & Suhner failed to
    answer a quote request. I was pleased to find that JYEBAO's
    cables were *better* than H+S, and cheaper too.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to jeroen@nospam.please on Mon Oct 7 10:28:20 2024
    On Sun, 6 Oct 2024 19:44:23 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 10/6/24 19:26, john larkin wrote:
    On Sun, 6 Oct 2024 17:46:02 +0200, Klaus Vestergaard Kragelund
    <klauskvik@hotmail.com> wrote:

    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the >>>> price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>>> Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to >>>> SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor >>>> with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s


    I solved a billion-dollar showstopper last year. Some country started
    demanding that some expensive semi fab gear be EMI tested, and our
    units failed. After great hassle we traced it to bad ground crimps on
    shielded CAT5 cables that our customer bought cheap.

    I bought a set of phase-matched cables from Taiwanese company
    JYEBAO because my usual supplier Huber & Suhner failed to
    answer a quote request. I was pleased to find that JYEBAO's
    cables were *better* than H+S, and cheaper too.

    Jeroen Belleman

    So ar, the generic cheap Amazon SMA and SMB cables have been
    excellent. As have been the edge-launch connectors.

    The Shining Star connectors are great too.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to jeroen@nospam.please on Tue Oct 8 11:23:42 2024
    On Sun, 6 Oct 2024 19:44:23 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 10/6/24 19:26, john larkin wrote:
    On Sun, 6 Oct 2024 17:46:02 +0200, Klaus Vestergaard Kragelund
    <klauskvik@hotmail.com> wrote:

    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time
    testing it today. I have to say it's amazing what they've done for the >>>> price. I mean, truly amazing. I do have two other 'proper' lab-grade
    RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>>> Anyway, to get back to the point of this post, having checked out the
    TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before
    which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to
    this question anyway. "So what is the fucking question, CD??" I hear
    you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator
    and I'm seeing the displayed amplitude vary as it sweeps through the
    range. But this only happens when I'm using a cheap, Chinese N-type to >>>> SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor >>>> with but it's a bit of an effort to do. It would seem like the SA is
    showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s


    I solved a billion-dollar showstopper last year. Some country started
    demanding that some expensive semi fab gear be EMI tested, and our
    units failed. After great hassle we traced it to bad ground crimps on
    shielded CAT5 cables that our customer bought cheap.

    I bought a set of phase-matched cables from Taiwanese company
    JYEBAO because my usual supplier Huber & Suhner failed to
    answer a quote request. I was pleased to find that JYEBAO's
    cables were *better* than H+S, and cheaper too.

    Jeroen Belleman

    Probably made next door to each other, or in the same
    sweat shop on different days.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to legg on Tue Oct 8 20:03:54 2024
    On 10/8/24 17:23, legg wrote:
    On Sun, 6 Oct 2024 19:44:23 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 10/6/24 19:26, john larkin wrote:
    On Sun, 6 Oct 2024 17:46:02 +0200, Klaus Vestergaard Kragelund
    <klauskvik@hotmail.com> wrote:

    On 29-09-2024 19:14, Cursitor Doom wrote:
    Greetings, gentlemen,

    I bought one of those TinySA Ultras recently and have spent some time >>>>> testing it today. I have to say it's amazing what they've done for the >>>>> price. I mean, truly amazing. I do have two other 'proper' lab-grade >>>>> RF spectrum analyzers, but I think I'm going to be mostly using the
    TinySA in future as it's just *so* convenient and doesn't weigh a ton. >>>>> Anyway, to get back to the point of this post, having checked out the >>>>> TSA and establishing I didn't buy one of the fake versions that are
    out there, I turned my attention to my mid-level RF SA, an HP who's
    model number escapes me (not the 8566B I've posted here about before >>>>> which is now fully working, but a newer model that's about 1/3 as
    heavy. I say I can't recall the model number but it's not relevant to >>>>> this question anyway. "So what is the fucking question, CD??" I hear >>>>> you not unreasonably cry. Well, it's this:
    When I'm feeding an RF signal into the SA, I'm seeing differing
    amplitudes at different frequencies. So I've programmed in a sweep
    from 10Mhz to 5.4Ghz at -49dBm using my Aeroflex RF signal generator >>>>> and I'm seeing the displayed amplitude vary as it sweeps through the >>>>> range. But this only happens when I'm using a cheap, Chinese N-type to >>>>> SMA adaptor at the signal generator output. Would I be right to
    suspect some imperfection in the manufacturing of the adaptor could
    cause such an effect? I do have a VNA I could characterize the adaptor >>>>> with but it's a bit of an effort to do. It would seem like the SA is >>>>> showing the adaptor's shortcomings in the frequency domain. But is
    that a feasible hypothesis?

    Measurement of good vs bad cables:

    https://www.youtube.com/watch?v=AqFDxQjJAdA&t=50s


    I solved a billion-dollar showstopper last year. Some country started
    demanding that some expensive semi fab gear be EMI tested, and our
    units failed. After great hassle we traced it to bad ground crimps on
    shielded CAT5 cables that our customer bought cheap.

    I bought a set of phase-matched cables from Taiwanese company
    JYEBAO because my usual supplier Huber & Suhner failed to
    answer a quote request. I was pleased to find that JYEBAO's
    cables were *better* than H+S, and cheaper too.

    Jeroen Belleman

    Probably made next door to each other, or in the same
    sweat shop on different days.

    RL

    I don't think so. I compared H+S matched sets with
    JYEBAO's and there were clear differences. The JYEBAO
    cables were clearly better matched, and of overall
    better quality too.

    Another positive experience I had with them concerned
    the delivery of cables with a 75 Ohm C connector at
    one end. Nobody makes 75 Ohm C connectors anymore, but
    they delivered.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)