Has the BBC still got the capability of broadcasting to Russia in the shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of
putting the Soviet Empire back together and will not take any notice of anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of
the media.
The internet has a certain degree of resilience, but can also be used to track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
Has the BBC still got the capability of broadcasting to Russia in the shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of
putting the Soviet Empire back together and will not take any notice of anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of
the media.
The internet has a certain degree of resilience, but can also be used to track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
In the UK I doubt we have the manpower or armour if we wanted to wage a war, the number of tanks wehave would only just fill a fir sized football stadium, as they seem to think waging war is now all going to be done remotely with drones and robots. Good luck with that when they get damaged and the radio links are jammed.
potential listeners would need to have suitable receivers.
On 27/02/2022 09:13, Liz Tuddenham wrote:
There is a definite case for the BBC resuming shortwave broadcasts inNo harm in it, but you're not going to get a critical mass of Russians
Russian if this can be done at short notice.
tuning in, and initiating any change.
How many ordinary Russians have a SW receiver, and are savvy enough to
use it ?
On 27/02/2022 09:34, Brian Gaff (Sofa) wrote:
In the UK I doubt we have the manpower or armour if we wanted to wage a
war, the number of tanks wehave would only just fill a fir sized football
stadium, as they seem to think waging war is now all going to be done
remotely with drones and robots. Good luck with that when they get
damaged
and the radio links are jammed.
We keep hearing the Russians do not have air superiority, I don't think
there are many Ukrainian Air Force aircraft operating so that suggests the ground based air defences are effective. We saw yesterday that the large mobile air defence systems are vulnerable though they have the advantage
of being able to handle multiple targets but it seems to suggest that the Ukrainians are having success with small man-carried missiles which they
are said to have been supplied with.
I noticed last night that a NATO AWACS was orbiting near the Romanian
border though of course only seeing aircraft with their transponders
active. Are they feeding information to the Ukrainians? There is one orbiting over Poland today.
There were also two RAF Eurofighters up - one around Turkey / Cyprus and
one around Denmark.
Also today a US F-35 around Germany / Poland, it had been orbiting over Poland.
These are only the ones we can see but it looks as if NATO is watching everying going on around Ukraine.
In article <1po12h5.hwsgmf11yvukuN%liz@poppyrecords.invalid.invalid>,
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Has the BBC still got the capability of broadcasting to Russia in the
shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of
putting the Soviet Empire back together and will not take any notice of
anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of
the media.
The internet has a certain degree of resilience, but can also be used to
track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local
oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
potential listeners would need to have suitable receivers.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
Has the BBC still got the capability of broadcasting to Russia in the shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of
putting the Soviet Empire back together and will not take any notice of anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of
the media.
The internet has a certain degree of resilience, but can also be used to track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
On 28/02/2022 15:56, Mark Carver wrote:
On 27/02/2022 09:13, Liz Tuddenham wrote:
There is a definite case for the BBC resuming shortwave broadcasts inNo harm in it, but you're not going to get a critical mass of Russians tuning in, and initiating any change.
Russian if this can be done at short notice.
How many ordinary Russians have a SW receiver, and are savvy enough to
use it ?
Probably about as many as are capable of using a proxy server to listen
to the World Service on their computer or tablet. They have a lot of excellent programmers.
Don't forget, some of the most annoying hacks on the web have been
Russian in origin.
I see a lot of old short wave radios around, but will that be true in
Russia? Its ironic, as during the soviet times, they used to produce some good ones themselves with names like Vga and Tesla, although technically the latter were made in one of the other countries.
I also listened to China Radio International yesterday, and they seem to be interested in perhaps getting involved and stopping him. I don't know enough about the geopolitics there to be able to make any reall assessment if its sabre rattling or actually true.
On 27/02/2022 09:13, Liz Tuddenham wrote:
Has the BBC still got the capability of broadcasting to Russia in the shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of putting the Soviet Empire back together and will not take any notice of anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of the media.
The internet has a certain degree of resilience, but can also be used to track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in Russian if this can be done at short notice.
No harm in it, but you're not going to get a critical mass of Russians
tuning in, and initiating any change.
How many ordinary Russians have a SW receiver, and are savvy enough to
use it ?
In article <j84a8bF64s7U1@mid.individual.net>,
John Williamson <johnwilliamson@btinternet.com> wrote
Don't forget, some of the most annoying hacks on the web have been
Russian in origin.
BA's computer system at the weekend?
On 27/02/2022 09:13, Liz Tuddenham wrote:
Has the BBC still got the capability of broadcasting to Russia in theNo harm in it, but you're not going to get a critical mass of Russians
shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of
putting the Soviet Empire back together and will not take any notice of
anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of
the media.
The internet has a certain degree of resilience, but can also be used to
track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local
oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
tuning in, and initiating any change.
How many ordinary Russians have a SW receiver, and are savvy enough to
use it ?
BA's computer system at the weekend?
In article <1po12h5.hwsgmf11yvukuN%liz@poppyrecords.invalid.invalid>,
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Has the BBC still got the capability of broadcasting to Russia in the shortwave bands?
It seems to me that Putin is trying to fulfil a childhood ambition of putting the Soviet Empire back together and will not take any notice of anything we threaten him with. The Russian people would not support him
in this if they knew the truth, but like all dictators he has control of the media.
The internet has a certain degree of resilience, but can also be used to track down those who receive unauthorised messages. Shortwave
broadcasting is much more difficult to block and shortwave receivers do
not give away their presence (imagine trying to direction-find a local oscillator when everyone around is using switch-mode power supplies).
There is a definite case for the BBC resuming shortwave broadcasts in Russian if this can be done at short notice.
potential listeners would need to have suitable receivers.
[...]There is a definite case for the BBC resuming shortwave broadcasts in Russian if this can be done at short notice.
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
[...]
[...]There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
15735 Kc/s 16:00-18:00 GMTThe BBC's website says: "These frequencies can be received clearly in
5875 Kc/s 22:00-00:00 GMT
Kyiv and parts of Russia". (They are World Service in English, not
actually in Russian.)
Nothing is audible here (Bath UK) on either frequency, not even a sniff
of a carrier below the background noise level. If they were being transmitted from anywhere in England, even with a directional array,
there should be some trace of them.
Either they haven't started yet or the transmitters are low powered and
local to Ukraine.
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
[...]
[...]There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
The BBC's website says: "These frequencies can be received clearly in
Kyiv and parts of Russia". (They are World Service in English, not
actually in Russian.)
Nothing is audible here (Bath UK) on either frequency, not even a sniff
of a carrier below the background noise level. If they were being transmitted from anywhere in England, even with a directional array,
there should be some trace of them.
Either they haven't started yet or the transmitters are low powered and
local to Ukraine.
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
The BBC's website says: "These frequencies can be received clearly in
Kyiv and parts of Russia". (They are World Service in English, not
actually in Russian.)
Nothing is audible here (Bath UK) on either frequency, not even a sniff
of a carrier below the background noise level. If they were being transmitted from anywhere in England, even with a directional array,
there should be some trace of them.
Either they haven't started yet or the transmitters are low powered and
local to Ukraine.
the BBC published a map of their SW coverage in Ukraine which FWLIW I
took to point to a local transmitter - possibly Poland
https://pbs.twimg.com/media/FM2hNpVXEAUa2kV.png
On 03/03/2022 10:49, Robin wrote:
the BBC published a map of their SW coverage in Ukraine which FWLIW I
took to point to a local transmitter - possibly Poland
https://pbs.twimg.com/media/FM2hNpVXEAUa2kV.png
Isn't that map showing that the UK/ Western Europe are in the Skip Zone ?
I'm pretty certain the Tx is at Wooferton
Mark Carver <mark.carver@invalid.invalid> wrote:
On 03/03/2022 10:49, Robin wrote:
the BBC published a map of their SW coverage in Ukraine which FWLIW I took to point to a local transmitter - possibly Poland
https://pbs.twimg.com/media/FM2hNpVXEAUa2kV.png
Isn't that map showing that the UK/ Western Europe are in the Skip Zone ?
I'm pretty certain the Tx is at Wooferton
https://en.wikipedia.org/wiki/Skip_zone
Does Woofferton offer directional transmission? IANA HF engineer but ISTM that any isotropic transmission would have a skip zone at a similar distance in all directions from the transmitter. Or are they doing some kind of phased array to beamform in the easterly direction?
(they have 10 HF transmitters according to wikipedia, but I'm not clear if that's 10 separate frequencies or they can be ganged together)
I'm not sure if this is current but the antenna setup looks pretty complicated - maybe that's where the directionality comes from?
http://tx.mb21.co.uk/gallery/gallerypage.php?txid=1628&pageid=1534
Theo
On 03/03/2022 10:49, Robin wrote:
the BBC published a map of their SW coverage in Ukraine which FWLIW I
took to point to a local transmitter - possibly Poland
https://pbs.twimg.com/media/FM2hNpVXEAUa2kV.png
Isn't that map showing that the UK/ Western Europe are in the Skip Zone ?
I'm pretty certain the Tx is at Wooferton
https://en.wikipedia.org/wiki/Skip_zone
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
The BBC's website says: "These frequencies can be received clearly in
Kyiv and parts of Russia". (They are World Service in English, not
actually in Russian.)
Nothing is audible here (Bath UK) on either frequency, not even a sniff
of a carrier below the background noise level. If they were being transmitted from anywhere in England, even with a directional array,
there should be some trace of them.
Either they haven't started yet or the transmitters are low powered and local to Ukraine.
From what I read elsewhere they're coming from Woofferton but *only* at the above times. They're silent the rest of the day - probably the transmitter retunes to some other frequency in the typical SW manner, so there's no carrier out of hours.
Ukraine is UTC+2 so the first one is 1800-2000 local time, the other one starts at midnight.
On 03/03/2022 11:01, Mark Carver wrote:
On 03/03/2022 10:49, Robin wrote:
the BBC published a map of their SW coverage in Ukraine which FWLIW
I took to point to a local transmitter - possibly Poland
https://pbs.twimg.com/media/FM2hNpVXEAUa2kV.png
Isn't that map showing that the UK/ Western Europe are in the Skip
Zone ?
I'm pretty certain the Tx is at Wooferton
OK, ta. (I knew I was probably displaying my ignorance but thought
that directional broadcasts from there would be centred better on
Ukraine.)
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
[...]
[...]There is a definite case for the BBC resuming shortwave broadcasts in
Russian if this can be done at short notice.
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
The BBC's website says: "These frequencies can be received clearly in
Kyiv and parts of Russia". (They are World Service in English, not
actually in Russian.)
Nothing is audible here (Bath UK) on either frequency, not even a sniff
of a carrier below the background noise level. If they were being transmitted from anywhere in England, even with a directional array,
there should be some trace of them.
Either they haven't started yet or the transmitters are low powered and
local to Ukraine.
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
Ukraine is UTC+2 so the first one is 1800-2000 local time, the other one starts at midnight.
If anything over a kilowatt is being radiated by Wooferton, even if I am
in their deepest null, I could hardly miss it.
On 03/03/2022 12:47, Liz Tuddenham wrote:
If all else fails, stay at the Travelodge in the village. I did that 30
If anything over a kilowatt is being radiated by Wooferton, even if I am
in their deepest null, I could hardly miss it.
years ago, more or less to see what it was like to be that close to a SW station.
The evening simply whizzed by as I checked EMC compatibility on a
collection of electronic devices I'd taken along in my suitcase
Yes. At least some of those arrays are Sterba Curtains which can
be slewed several degrees either way. It looks to me as though
the coverage pic. is showing side-lobes. I used to work on similar
arrays at BBC Skelton in the late '60s.
Don't the BBC WS still have transmitters in Cyprus
or Ascension Island?
On 03/03/2022 14:17, Mark Carver wrote:
On 03/03/2022 12:47, Liz Tuddenham wrote:
If all else fails, stay at the Travelodge in the village. I did that
If anything over a kilowatt is being radiated by Wooferton, even if
I am
in their deepest null, I could hardly miss it.
30 years ago, more or less to see what it was like to be that close
to a SW station.
The evening simply whizzed by as I checked EMC compatibility on a
collection of electronic devices I'd taken along in my suitcase
I assume that was before you were married?
Theo <theom+news@chiark.greenend.org.uk> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:[...]
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
Ukraine is UTC+2 so the first one is 1800-2000 local time, the other oneThe transmission started on 15735 Kc/s at about 14:00 GMT. I think the
starts at midnight.
times given on the website are Ukrainian local time. (16:00 ULT = 14:00
GMT)
There is light fading on the signal, which is not very strong, so I
suspect it is coming from further away than Woofferton. Are there any propagation experts in the group who can confirm this?
BBC News
BBC News launches 'dark web' Tor mirror
https://www.bbc.co.uk/news/technology-50150981
On 03/03/2022 14:19, Liz Tuddenham wrote:
Theo <theom+news@chiark.greenend.org.uk> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:[...]
15735 Kc/s 16:00-18:00 GMT
5875 Kc/s 22:00-00:00 GMT
Ukraine is UTC+2 so the first one is 1800-2000 local time, the other one >> starts at midnight.The transmission started on 15735 Kc/s at about 14:00 GMT. I think the times given on the website are Ukrainian local time. (16:00 ULT = 14:00 GMT)
There is light fading on the signal, which is not very strong, so I
suspect it is coming from further away than Woofferton. Are there any propagation experts in the group who can confirm this?
Reading some of the reception reports from SW enthusiasts, there seems consensus it's coming from Wooferton, but the UK is deep inside the skip zone.
Someone not far from you is getting a poor signal in Bristol.
On Fri, 4 Mar 2022 13:02:07 +0000, MB <MB@nospam.net> wrote:
BBC News
BBC News launches 'dark web' Tor mirror
https://www.bbc.co.uk/news/technology-50150981
Typically of a mainstream article about anything on the internet, they
tell you everything about it except how to access it.
By reducing the bandwidth of the receiver and sweeping a channel. it is relatively easy to hear beat notes 10dB below the noise level. I could
hear no carrier beats on the advertised frequencies at the advertised
times, which would point to to an attenuation of at least 216dB in the
signal path between Woofferton and Bath (about 150 km).
On 05/03/2022 09:49, Liz Tuddenham wrote:
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10
By reducing the bandwidth of the receiver and sweeping a channel. it is
relatively easy to hear beat notes 10dB below the noise level.  I could >> hear no carrier beats on the advertised frequencies at the advertised
times, which would point to to an attenuation of at least 216dB in the
signal path between Woofferton and Bath (about 150 km).
to 1.
You wouldn't even get that level of attenuation if you were trying to
receive Wooferton on the other side of the galaxy
Robin <rbw@outlook.com> wrote:[]
Space is big. Really big. You just won’t believe how vastly, hugely, >> mind-bogglingly big it is. I mean, you may think it’s a long way down >> the street to the chemist, but that’s just peanuts to space...
If you think I'm carrying an Eddystone 830 down the street, even as far
as the chemist's, just to see if the signal is stronger there, you've
got another think coming. :-)
On 05/03/2022 16:54, Mark Carver wrote:
On 05/03/2022 09:49, Liz Tuddenham wrote:
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10
By reducing the bandwidth of the receiver and sweeping a channel. it is
relatively easy to hear beat notes 10dB below the noise level.  I could >> hear no carrier beats on the advertised frequencies at the advertised
times, which would point to to an attenuation of at least 216dB in the
signal path between Woofferton and Bath (about 150 km).
to 1.
I think your post was attenuated and lost "0" before the full stop :)
You wouldn't even get that level of attenuation if you were trying to receive Wooferton on the other side of the galaxy
t'other side of the galaxy is about 5 x 10^17 km away* - that's a lot of attenuation - even leaving aside the matter in the way.
Space is big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down
the street to the chemist, but that’s just peanuts to space...
On Sat, 05 Mar 2022 14:21:01 +0000, BrightsideS9 <reply_to_address_is_not@invalid.invalid> wrote:
On Sat, 05 Mar 2022 09:03:25 +0000, Roderick Stewart
<rjfs@escapetime.myzen.co.uk> wrote:
On Fri, 4 Mar 2022 13:02:07 +0000, MB <MB@nospam.net> wrote:
BBC News
BBC News launches 'dark web' Tor mirror
https://www.bbc.co.uk/news/technology-50150981
Typically of a mainstream article about anything on the internet, they
tell you everything about it except how to access it.
Download TOR browser from
https://www.torproject.org/download/languages/
choose your language and system to get the correct browser.
Go to settings and select "connect" automatically.
Connection to network will activate when browser is loaded.
You can then copy the URL in the BBC site referenced above to test.
I wasn't really interested in visiting the "dark web", just remarking
that the BBC had yet again published an article on the subject and
missed out the most important piece of information, the one thing that
anyone ineterested would surely want to know. This seems to happen
whenever any mainstream outlet, broadcast or newspaper, produces an
item about anything technical - look, here's a new and wonderful
thing, it can do this, it can do that, but we're not going to tell you
how to get it.
Rod.
Space is big. Really big. You just won’t believe how vastly, hugely, >mind-bogglingly big it is. I mean, you may think it’s a long way down
the street to the chemist, but that’s just peanuts to space...
On Sat, 05 Mar 2022 09:03:25 +0000, Roderick Stewart ><rjfs@escapetime.myzen.co.uk> wrote:
On Fri, 4 Mar 2022 13:02:07 +0000, MB <MB@nospam.net> wrote:
BBC News
BBC News launches 'dark web' Tor mirror
https://www.bbc.co.uk/news/technology-50150981
Typically of a mainstream article about anything on the internet, they
tell you everything about it except how to access it.
Download TOR browser from
https://www.torproject.org/download/languages/
choose your language and system to get the correct browser.
Go to settings and select "connect" automatically.
Connection to network will activate when browser is loaded.
You can then copy the URL in the BBC site referenced above to test.
There's a lot of it, but not much in it.Apparently there are more atoms in space than in all the celestial
(I think that's why it's called space).
Rod.
I wasn't really interested in visiting the "dark web", just remarking
that the BBC had yet again published an article on the subject and
missed out the most important piece of information, the one thing that
anyone ineterested would surely want to know. This seems to happen
whenever any mainstream outlet, broadcast or newspaper, produces an
item about anything technical - look, here's a new and wonderful
thing, it can do this, it can do that, but we're not going to tell you
how to get it.
Rod.
thing, it can do this, it can do that, but we're not going to tell you
how to get it.
On 05/03/2022 09:49, Liz Tuddenham wrote:
By reducing the bandwidth of the receiver and sweeping a channel. it is relatively easy to hear beat notes 10dB below the noise level. I could hear no carrier beats on the advertised frequencies at the advertised times, which would point to to an attenuation of at least 216dB in the signal path between Woofferton and Bath (about 150 km).
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10
to 1.
You wouldn't even get that level of attenuation if you were trying to
receive Wooferton on the other side of the galaxy
Mark Carver <mark.carver@invalid.invalid> wrote:
On 05/03/2022 09:49, Liz Tuddenham wrote:
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10
By reducing the bandwidth of the receiver and sweeping a channel. it is
relatively easy to hear beat notes 10dB below the noise level. I could >>> hear no carrier beats on the advertised frequencies at the advertised
times, which would point to to an attenuation of at least 216dB in the
signal path between Woofferton and Bath (about 150 km).
to 1.
You wouldn't even get that level of attenuation if you were trying to
receive Wooferton on the other side of the galaxy
I've worked it out that if Woofferton's 250 kW was spread out unifomly
over the surface of a sphere 150 km radius, the power would be
approximately 1.8x10^-11 watts per square metre. The receiver can
detect signals of 5x10^-17 watts, so even allowing for aerial nulls and
other technical factors, there is a lot of attenuation in the signal
path if Woofferton really is keeping to the times and frequencies
stated.
If there is no skip path, I wonder if the attenuation can be accounted
for by the curvature of the Earth. My aerial is about 100 metres ASL
and Woofferton is 'low lying' (whatever that means), so there is quite a
bit of high ground in between.
On 05/03/2022 16:54, Mark Carver wrote:
On 05/03/2022 09:49, Liz Tuddenham wrote:
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10
By reducing the bandwidth of the receiver and sweeping a channel. it is
relatively easy to hear beat notes 10dB below the noise level.  I could >>> hear no carrier beats on the advertised frequencies at the advertised
times, which would point to to an attenuation of at least 216dB in the
signal path between Woofferton and Bath (about 150 km).
to 1.
I think your post was attenuated and lost "0" before the full stop :)
You wouldn't even get that level of attenuation if you were trying to
receive Wooferton on the other side of the galaxy
t'other side of the galaxy is about 5 x 10^17 km away* - that's a lot of >attenuation - even leaving aside the matter in the way.
Space is big. Really big. You just won’t believe how vastly, hugely, >mind-bogglingly big it is. I mean, you may think it’s a long way down
the street to the chemist, but that’s just peanuts to space...
On Sun 06/03/2022 11:59, Liz Tuddenham wrote:
Mark Carver <mark.carver@invalid.invalid> wrote:
On 05/03/2022 09:49, Liz Tuddenham wrote:
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10 >> to 1.
By reducing the bandwidth of the receiver and sweeping a channel. it is >>> relatively easy to hear beat notes 10dB below the noise level. I could >>> hear no carrier beats on the advertised frequencies at the advertised
times, which would point to to an attenuation of at least 216dB in the >>> signal path between Woofferton and Bath (about 150 km).
You wouldn't even get that level of attenuation if you were trying to
receive Wooferton on the other side of the galaxy
I've worked it out that if Woofferton's 250 kW was spread out unifomly
over the surface of a sphere 150 km radius, the power would be approximately 1.8x10^-11 watts per square metre. The receiver can
detect signals of 5x10^-17 watts, so even allowing for aerial nulls and other technical factors, there is a lot of attenuation in the signal
path if Woofferton really is keeping to the times and frequencies
stated.
If there is no skip path, I wonder if the attenuation can be accounted
for by the curvature of the Earth. My aerial is about 100 metres ASL
and Woofferton is 'low lying' (whatever that means), so there is quite a bit of high ground in between.
I suspect there is a calculation error there somewhere.
1uV=-137dBW
5e-17 = -163dBW which is 0.05uV.
I have never heard of any sort of receiver (other then maybe
supercooled) that can use that sort of signal level!
Woody <harrogate3@ntlworld.com> wrote:
On Sun 06/03/2022 11:59, Liz Tuddenham wrote:
Mark Carver <mark.carver@invalid.invalid> wrote:
On 05/03/2022 09:49, Liz Tuddenham wrote:
An attenuation of 216dB corresponds to a ratio of 6.3 to the power of 10 >> to 1.
By reducing the bandwidth of the receiver and sweeping a channel. it is >>> relatively easy to hear beat notes 10dB below the noise level. I could
hear no carrier beats on the advertised frequencies at the advertised >>> times, which would point to to an attenuation of at least 216dB in the >>> signal path between Woofferton and Bath (about 150 km).
You wouldn't even get that level of attenuation if you were trying to
receive Wooferton on the other side of the galaxy
I've worked it out that if Woofferton's 250 kW was spread out unifomly over the surface of a sphere 150 km radius, the power would be approximately 1.8x10^-11 watts per square metre. The receiver can
detect signals of 5x10^-17 watts, so even allowing for aerial nulls and other technical factors, there is a lot of attenuation in the signal
path if Woofferton really is keeping to the times and frequencies
stated.
If there is no skip path, I wonder if the attenuation can be accounted for by the curvature of the Earth. My aerial is about 100 metres ASL
and Woofferton is 'low lying' (whatever that means), so there is quite a bit of high ground in between.
I suspect there is a calculation error there somewhere.
1uV=-137dBW
5e-17 = -163dBW which is 0.05uV.
I have never heard of any sort of receiver (other then maybe
supercooled) that can use that sort of signal level!
You are right, I must have gone wrong somewhere, so I have done some
more tests and calculations:
The spec. for the Eddystone 830 is 3 microvolts into 75 ohms for a S/N
ratio of 15 dB. Thats 1.2x10^-13 watts and the S/N ratio is the
receiver's internal noise, not the noise floor picked up on the aerial.
From that, a signal of 1uV would give a S/N ratio of about 5dB, at which
a carrier would be very easy to detect with the BFO switched on. In
practice a signal 10dB below receiver noise can be detected by ear if
the tuning is swept through it. That corresponds to a carrier of -143
dBW.
The measurements I made of the receiver's sensitivity were taken with
the signal generator connected to a frequency counter, now I have disconnected the frequency counter and capped off the high level output
on the back panel of the sig gen, the signal is much lower. The
receiver must have been picking up radiation from the lead to the
counter.
A carrier at 0.2uv is now just detectable as a beat with the BFO. That corresponds to -153 dBW into 75 ohms. (Now you know why C.W. is still
used when all else fails.) That is a respectable performance for a
valve receiver dating from the 1960s at room temperature.
What I hadn't previously taken account of was the noise level picked up
on the aerial, which measures 43dB higher than that of the receiver
itself. That means the signal from Woofferton would have to be -110dBW
on the aerial to be detected. I'm quite surprised that I don't seem to
have uncovered any flaws in my calculations (quite unusual for me) or
perhaps I have missed them or made a complementary second one. Please
check and let me know,.
Having done all that, I can now update you on my actual experience: I
have been hearing signals on the scheduled frequencies, but not at the scheduled times. From the programme content I would guess that it is
the World Service. The signal is not very strong and the S/N ratio is sometimes so poor that words or whole sentences are missed.
That doesn't matter as long as it is clearly audible in the target area (which it probably is) and as long as it carries programmes that are appropriate for the intended audience (which is more doubtful).
There was an article on shortwave broadcasting as a more robust
alternative to the internet on Radio 4 at lunchtime; filling in the
history but not saying what the BBC are actually doing about it.
On 06/03/2022 11:44, williamwright wrote:
thing, it can do this, it can do that, but we're not going to tell you
how to get it.
I thought they did say how to get it as was confirmed by another post?
omce upom a time, all these overseas broadcasts were pid for by the foreign officee, They are now paid for by the UK licence payer.
You might be hreaing Wooferton when the antenna direction is in a more southerly direction . ie the service is being broadcast to somewhere else
omce upom a time, all these overseas broadcasts were pid for by the foreign >> officee, They are now paid for by the UK licence payer.
In the end, we are still the people who pay for it, only the route taken
by the money is different.
On Mon, 7 Mar 2022 at 12:46:35, Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote (my responses usually FOLLOW): >charles <charles@candehope.me.uk> wrote:
omce upom a time, all these overseas broadcasts were pid for by the foreign
officee, They are now paid for by the UK licence payer.
In the end, we are still the people who pay for it, only the route taken
by the money is different.
True, but it _does_ make a difference; if the BBC now has to fund them, decisions (e. g. about what services - such as languages - to provide at
all, and what and which transmitters to use) are made by different
people.
[]
On Mon, 7 Mar 2022 at 12:46:35, Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote (my responses usually FOLLOW):
charles <charles@candehope.me.uk> wrote:
omce upom a time, all these overseas broadcasts were pid for by the
foreign
officee, They are now paid for by the UK licence payer.
In the end, we are still the people who pay for it, only the route taken
by the money is different.
True, but it _does_ make a difference; if the BBC now has to fund them, decisions (e. g. about what services - such as languages - to provide at
all, and what and which transmitters to use) are made by different people.
[]
J. P. Gilliver (John) <G6JPG@255soft.uk> wrote:
On Mon, 7 Mar 2022 at 12:46:35, Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote (my responses usually FOLLOW): >charles <charles@candehope.me.uk> wrote:
omce upom a time, all these overseas broadcasts were pid for by the
foreign officee, They are now paid for by the UK licence payer.
In the end, we are still the people who pay for it, only the route taken >by the money is different.
True, but it _does_ make a difference; if the BBC now has to fund them, decisions (e. g. about what services - such as languages - to provide at all, and what and which transmitters to use) are made by different
people.
[]
Why does that (and listening on shortwave in general) make me feel
incredibly depressed?
In article <j849l2F61deU1@mid.individual.net>, Mark Carver <mark.carver@invalid.invalid> scribeth thus
No harm in it, but you're not going to get a critical mass of Russians
tuning in, and initiating any change.
How many ordinary Russians have a SW receiver, and are savvy enough to
use it ?
It will be the oligarchs money men that will change it all, wait and
see!....
There was a time when I thought my beloved short waves were
totally obsolete, superseded by this new fangled Internet thingy.
Now, it seems that SW is ultimately more resilient than the net.
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