I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
On 21/12/2022 20:53, Scott wrote:
I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
At a guess, maybe someone has worked out in advance the time delay
between the start of each track and the start of its lyrics, and the
jingle player therefore knows when to start the jingle so it only
crashes the introduction and shuts up just before the lyrics start.
For all I know, the record labels may even supply the timings for the
copies that are bought by radio stations so jingles can be inserted.
I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
2. Are the records chosen by a person in advance of the show or does
the computer choose them from the station's playlist either randomly
or using an algorithm?
On 21/12/2022 20:53, Scott wrote:
I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
It's all in the meta data
2. Are the records chosen by a person in advance of the show or does
the computer choose them from the station's playlist either randomly
or using an algorithm?
The first, driven by the second
Often the latter, it can even cope with what might be seen as random sized voice tracks. This of course means a guy doing overnights can do it in about half an hour.
Brian
On 21/12/2022 20:53, Scott wrote:
I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
At a guess, maybe someone has worked out in advance the time delay between the start of each track and the start of its lyrics, and the jingle player therefore knows when to start the jingle so it only crashes the
introduction and shuts up just before the lyrics start.
For all I know, the record labels may even supply the timings for the
copies that are bought by radio stations so jingles can be inserted.
I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
2. Are the records chosen by a person in advance of the show or does
the computer choose them from the station's playlist either randomly
or using an algorithm?
In article <J7mdnWzWS_0n7j7-nZ2dnZfqnPadnZ2d@brightview.co.uk>, NY <me@privacy.net> scribeth thus
On 21/12/2022 20:53, Scott wrote:
I have taken to listening to Gold (Global) some of the time. Apart
from the breakfast show, it seems to be fully automated. I have a
couple of questions:
1. How does the computer manage to time the jingles ('Destination
midnight, this is Gold etc) so as to fit in before the lyrics of the
record start?
At a guess, maybe someone has worked out in advance the time delay
between the start of each track and the start of its lyrics, and the
jingle player therefore knows when to start the jingle so it only
crashes the introduction and shuts up just before the lyrics start.
For all I know, the record labels may even supply the timings for the >>copies that are bought by radio stations so jingles can be inserted.
This is around the industry standard playout system they even have
zetta2go that you can run from home as some presenters do!..
https://www.rcsworks.com/zetta/
--
Tony Sayer
Man is least himself when he talks in his own person.
Give him a keyboard, and he will reveal himself.
On a related note, many "local" FM stations (there was never anything
local about them!) have now become relays of 'Hits Radio', to form a >quasi-national network, but some (at least for now) still retain
their old station name, such as "Radio City" in Liverpool.
They've somehow found a way of seamlessly inserting audio of the DJ
giving the correct station name on each station into his or her live >voiceovers, which are otherwise identical on all the stations.
Even the inflections are correctly matched.
On Tue, 27 Dec 2022 16:56:01 -0000, "Alexander" <none@nowhere.fr>
wrote:
On a related note, many "local" FM stations (there was never anything >>local about them!) have now become relays of 'Hits Radio', to form a >>quasi-national network, but some (at least for now) still retainSame in Scotland with Planet radio / Bauer. Clyde 2, Forth 2, Tay 2, Northsound 2 etc are essentially the same station with local jingles -
their old station name, such as "Radio City" in Liverpool.
They've somehow found a way of seamlessly inserting audio of the DJ
giving the correct station name on each station into his or her live >>voiceovers, which are otherwise identical on all the stations.
Even the inflections are correctly matched.
andI assume adverts added. Sometimes the link is specific to one
staton. I assume the presenter can record different links while
tracks are playing. One DJ I vaguely know will address Clyde 1
listeners with some very Weegie specific detail.
"Scott" <newsgroups@gefion.myzen.co.uk> wrote in message news:9j9mqhp282o5tjdt5u5p900fb3p5e91fa4@4ax.com...
On Tue, 27 Dec 2022 16:56:01 -0000, "Alexander" <none@nowhere.fr>
wrote:
On a related note, many "local" FM stations (there was never anything >>>local about them!) have now become relays of 'Hits Radio', to form a >>>quasi-national network, but some (at least for now) still retainSame in Scotland with Planet radio / Bauer. Clyde 2, Forth 2, Tay 2,
their old station name, such as "Radio City" in Liverpool.
They've somehow found a way of seamlessly inserting audio of the DJ >>>giving the correct station name on each station into his or her live >>>voiceovers, which are otherwise identical on all the stations.
Even the inflections are correctly matched.
Northsound 2 etc are essentially the same station with local jingles -
andI assume adverts added. Sometimes the link is specific to one
staton. I assume the presenter can record different links while
tracks are playing. One DJ I vaguely know will address Clyde 1
listeners with some very Weegie specific detail.
I'm surprised the BBC haven't employed the same technology for their
"local" radio stations, most of which now carry common programming
(shared between multiple stations) for much of the day.
Currently the presenter simply says that one is listening to "BBC
local radio".
Perhaps they are doing this on purpose, in the hope of generating a
public backlash - good luck with that if so...
On Tue, 3 Jan 2023 23:19:23 -0000, "Alexander" <none@nowhere.fr>
wrote:
Currently the presenter simply says that one is listening to "BBC
local radio".
Yes, it seems not to be done at a 'national' level.
Or perhaps there is an Ofcom rule to prevent the BBC attempting to
Perhaps they are doing this on purpose, in the hope of generating a
public backlash - good luck with that if so...
mislead but with different rules for merged local stations and single
output. If anyone has a couple of days to spare, they could peruse
the Ofcom guidance (they are not known for brevity).
"Scott" <newsgroups@gefion.myzen.co.uk> wrote in message news:r9rarhdekp26c6n1tni4ci89tk0u7dsojc@4ax.com...
On Tue, 3 Jan 2023 23:19:23 -0000, "Alexander" <none@nowhere.fr>
wrote:
Currently the presenter simply says that one is listening to "BBC
local radio".
Yes, it seems not to be done at a 'national' level.
Or perhaps there is an Ofcom rule to prevent the BBC attempting to
Perhaps they are doing this on purpose, in the hope of generating a >>>public backlash - good luck with that if so...
mislead but with different rules for merged local stations and single
output. If anyone has a couple of days to spare, they could peruse
the Ofcom guidance (they are not known for brevity).
Perhaps there is such a rule, but I would expect the opposite -
an obligation to provide proper station identification at regular
intervals.
It's a pity Ofcom doesn't enforce minimum standards of audio quality
as (I think) the IBA used to do.
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day - and I mean 'day'
On 04/01/2023 18:41, Scott wrote:
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
On 04/01/2023 18:41, Scott wrote:
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day -Â and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll
off, -20dB at 6 kHz, -40dB at 7 kHz
Today all AM transmissions will be no better than that, and probably worse.
Back in the 50s/60s I think the BBC used wider bandwidth on 1500m ?
In the US they use 10 kHz channels, and something like 50 kHz separation >between channels in a given area (because they've got a bloody huge
country with large distances between major cities) so their bandwidth is
10 kHz (maybe slightly more ?)
AM sounds completely different there, casually the same quality as FM
I read somewhere but I don't have a source (though Mark probably
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
On 05/01/2023 08:51, Scott wrote:
I read somewhere but I don't have a source (though Mark probably
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
I think you have to go back a long time
for when the audio on Medium
Wave transmitters was not filtered though few PO lines would have 15KHz
or higher.
The distribution system has been digital in one form or other for some
time and would have a 15 KHz filter.
The 9KHz bandwidth is because of the channel spacing on Medium Wave.
When comparing 'quality' of transmission modes, there are more factors
than just bandwidth.
On Thu, 5 Jan 2023 08:59:43 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>> offer 'near CD quality' and I would suggest may not meet the quality >>>> of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll >off, -20dB at 6 kHz, -40dB at 7 kHz
I am talking about earlier than that. What I read was that
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
AM sounds completely different there, casually the same quality as FM
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day -Â and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll
off, -20dB at 6 kHz, -40dB at 7 kHz
Today all AM transmissions will be no better than that, and probably worse.
Back in the 50s/60s I think the BBC used wider bandwidth on 1500m ?
In the US they use 10 kHz channels, and something like 50 kHz separation between channels in a given area (because they've got a bloody huge
country with large distances between major cities) so their bandwidth is
10 kHz (maybe slightly more ?)
AM sounds completely different there, casually the same quality as FM
On Thu, 5 Jan 2023 08:59:43 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>> of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll
off, -20dB at 6 kHz, -40dB at 7 kHz
I am talking about earlier than that. What I read was that
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
On 05/01/2023 09:08, Scott wrote:
On Thu, 5 Jan 2023 08:59:43 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>>> of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>>> more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>>> that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave >>>> in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll >>> off, -20dB at 6 kHz, -40dB at 7 kHz
I am talking about earlier than that. What I read was that
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
were there any "high quality" AM tuners before FM came in?
On Thu 05/01/2023 08:59, Mark Carver wrote:
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>> of AM in its day -Â and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp
roll off, -20dB at 6 kHz, -40dB at 7 kHz
Today all AM transmissions will be no better than that, and probably
worse.
Back in the 50s/60s I think the BBC used wider bandwidth on 1500m ?
In the US they use 10 kHz channels, and something like 50 kHz
separation between channels in a given area (because they've got a
bloody huge country with large distances between major cities) so
their bandwidth is 10 kHz (maybe slightly more ?)
AM sounds completely different there, casually the same quality as FM
Mark, Wasn't it that the channel spacing on LW and MW was 9KHz but
that included a guard band of 500Hz at either end, so in reality the
audio bandwidth was limited to 4KHz - which was (and largely still is)
the audio bandwidth of a standard PO private wire. Such lines of
course these days are quite sharply limited to 3.4KHz, even on AoD
circuits.
On Thu, 5 Jan 2023 12:49:33 +0000, Max Demian <max_demian@bigfoot.com>Take a radio designed for the European market to the US, and the
wrote:
On 05/01/2023 09:08, Scott wrote:What would happen in a situation like that? Does this mean a
On Thu, 5 Jan 2023 08:59:43 +0000, Mark CarverI doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:I am talking about earlier than that. What I read was that
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>>>> of AM in its day - and I mean 'day'Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>>>> more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>>>> that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave >>>>> in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll >>>> off, -20dB at 6 kHz, -40dB at 7 kHz
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
were there any "high quality" AM tuners before FM came in?
'European' AM radio does not work in the US because the transmitted
bandwidth is higher?
Mark, Wasn't it that the channel spacing on LW and MW was 9KHz but
that included a guard band of 500Hz at either end, so in reality the
audio bandwidth was limited to 4KHz - which was (and largely still is)
the audio bandwidth of a standard PO private wire. Such lines of
course these days are quite sharply limited to 3.4KHz, even on AoD
circuits.
I don't think analogue audio circuits for broadcasting have existed for
a long time now, possibly not for 20 years ?
GPO/BT provided a range of guaranteed bandwidths for landlines. However,
(and do the maths) the bandwidth of a passive twisted pair bit of copper (which is all an analogue land line ever was) vastly exceeds 15 kHz,
even when it's 'miles' long, it's when it hits some sort of termination device, (telephone, equalising amp etc) that that bandwidth drops.
The other killer though is Group Delay.
On 05/01/2023 12:55, Scott wrote:
On Thu, 5 Jan 2023 12:49:33 +0000, Max Demian <max_demian@bigfoot.com>Take a radio designed for the European market to the US, and the
wrote:
On 05/01/2023 09:08, Scott wrote:What would happen in a situation like that? Does this mean a
On Thu, 5 Jan 2023 08:59:43 +0000, Mark CarverI doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:I am talking about earlier than that. What I read was that
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>>>>> of AM in its day - and I mean 'day'Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>>>>> more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>>>>> that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave >>>>>> in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll >>>>> off, -20dB at 6 kHz, -40dB at 7 kHz
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
were there any "high quality" AM tuners before FM came in?
'European' AM radio does not work in the US because the transmitted
bandwidth is higher?
stations may not sound much better than they do here. (Depends how
tightly the Rx passband is set up) .
If your radio is digitally tuned, it will be useless there anyway,
because the 9 kHz tuning steps won't match the US 10 kHz ones (unless of >course the station is on 900 kHz etc)
Some radios (upmarket 'comms' style) are switchable between 9 and 10 kHz
On 05/01/2023 12:38, Mark Carver wrote:
I don't think analogue audio circuits for broadcasting have existed for
a long time now, possibly not for 20 years ?
GPO/BT provided a range of guaranteed bandwidths for landlines. However,
(and do the maths) the bandwidth of a passive twisted pair bit of copper
(which is all an analogue land line ever was) vastly exceeds 15 kHz,
even when it's 'miles' long, it's when it hits some sort of termination
device, (telephone, equalising amp etc) that that bandwidth drops.
The other killer though is Group Delay.
I vaguely remember reading that for some places, such as the Royal
Albert Hall, the BBC use to aggregate two or more POTS lines to increase >available bandwidth. I could be wrong though, this was in the 1960s.
On 05/01/2023 11:58, Woody wrote:
On Thu 05/01/2023 08:59, Mark Carver wrote:
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>> of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>> more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>> that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave >>> in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp
roll off, -20dB at 6 kHz, -40dB at 7 kHz
Today all AM transmissions will be no better than that, and probably
worse.
Back in the 50s/60s I think the BBC used wider bandwidth on 1500m ?
In the US they use 10 kHz channels, and something like 50 kHz
separation between channels in a given area (because they've got a
bloody huge country with large distances between major cities) so
their bandwidth is 10 kHz (maybe slightly more ?)
AM sounds completely different there, casually the same quality as FM
Mark, Wasn't it that the channel spacing on LW and MW was 9KHz but
that included a guard band of 500Hz at either end, so in reality the
audio bandwidth was limited to 4KHz - which was (and largely still is)
the audio bandwidth of a standard PO private wire. Such lines of
course these days are quite sharply limited to 3.4KHz, even on AoD circuits.
I don't think analogue audio circuits for broadcasting have existed for
a long time now, possibly not for 20 years ?
GPO/BT provided a range of guaranteed bandwidths for landlines. However,
(and do the maths) the bandwidth of a passive twisted pair bit of copper (which is all an analogue land line ever was) vastly exceeds 15 kHz,
even when it's 'miles' long,
it's when it hits some sort of termination
device, (telephone, equalising amp etc) that that bandwidth drops.
The other killer though is Group Delay.
On Thu, 5 Jan 2023 13:14:13 +0000, John Williamson
I vaguely remember reading that for some places, such as the Royal
Albert Hall, the BBC use to aggregate two or more POTS lines to increase
available bandwidth. I could be wrong though, this was in the 1960s.
What was the purpose of this if there was only one line to the
transmitter? Was it for television perhaps?
On 05/01/2023 12:38, Mark Carver wrote:
I don't think analogue audio circuits for broadcasting have existed for
a long time now, possibly not for 20 years ?
GPO/BT provided a range of guaranteed bandwidths for landlines. However,
(and do the maths) the bandwidth of a passive twisted pair bit of copper
(which is all an analogue land line ever was) vastly exceeds 15 kHz,
even when it's 'miles' long, it's when it hits some sort of termination
device, (telephone, equalising amp etc) that that bandwidth drops.
The other killer though is Group Delay.
I vaguely remember reading that for some places, such as the Royal
Albert Hall, the BBC use to aggregate two or more POTS lines to
increase available bandwidth. I could be wrong though, this was in the
1960s. I suspect mean a stereo matched pair ? (Which were expensive)
On Thu, 5 Jan 2023 13:01:56 +0000, Mark CarverEven better !
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 12:55, Scott wrote:I have seen one you can change to 1 kHz increments.
On Thu, 5 Jan 2023 12:49:33 +0000, Max Demian <max_demian@bigfoot.com>Take a radio designed for the European market to the US, and the
wrote:
On 05/01/2023 09:08, Scott wrote:What would happen in a situation like that? Does this mean a
On Thu, 5 Jan 2023 08:59:43 +0000, Mark CarverI doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs: >>>> were there any "high quality" AM tuners before FM came in?
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:I am talking about earlier than that. What I read was that
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably >>>>>>> knows) that in the very old days the bandwidth for some AM
I certainly agree with that - especially on DAB that was supposed to >>>>>>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>>>>>> of AM in its day - and I mean 'day'Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>>>>>> more channels.
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>>>>>> that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave >>>>>>> in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll >>>>>> off, -20dB at 6 kHz, -40dB at 7 kHz
'unofficially' some BBC Home Service transmitters (where sharing was >>>>> less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
'European' AM radio does not work in the US because the transmitted
bandwidth is higher?
stations may not sound much better than they do here. (Depends how
tightly the Rx passband is set up) .
If your radio is digitally tuned, it will be useless there anyway,
because the 9 kHz tuning steps won't match the US 10 kHz ones (unless of
course the station is on 900 kHz etc)
Some radios (upmarket 'comms' style) are switchable between 9 and 10 kHz
When did digital start? I would assume 1970s. Before then, would the
signal depend on the length of the PO line, quality of the cable, age
of the cable, design features etc or were they all the same? Would
Brookmans Park have a different arrangement because it is near London
(I believe Crystal Palace has or had).
"Mark Carver" <mark.carver@invalid.invalid> wrote in message news:k1nhrvF986fU2@mid.individual.net...
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
I read somewhere but I don't have a source (though Mark probably
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll
off, -20dB at 6 kHz, -40dB at 7 kHz
Today all AM transmissions will be no better than that, and probably worse. >>
Back in the 50s/60s I think the BBC used wider bandwidth on 1500m ?
In the US they use 10 kHz channels, and something like 50 kHz separation
between channels in a given area (because they've got a bloody huge
country with large distances between major cities) so their bandwidth is
10 kHz (maybe slightly more ?)
It's a few decades too late now, but in theory if they'd opted for an
AM broadcast standard in which one of the sidebands was suppressed, >presumably twice the audio bandwidth could have fitted into the same
amount of airspace?
Atlantic 252 in its early days partially implemented this I think?
The carrier frequency was slightly below 252 KHz, with the lower
sideband's bandwidth narrowed so that the upper sideband could be
wider.
I recall it sounded great on a particular (cheap) radio I had at the
time, which had rotary tuning and presumably more liberal bandwidth
filtering than most.
On 05/01/2023 13:58, Scott wrote:
On Thu, 5 Jan 2023 13:14:13 +0000, John WilliamsonProbably just trying to minimise quality loss for archived material or
I vaguely remember reading that for some places, such as the Royal
Albert Hall, the BBC use to aggregate two or more POTS lines to increase >>> available bandwidth. I could be wrong though, this was in the 1960s.
What was the purpose of this if there was only one line to the
transmitter? Was it for television perhaps?
they were using the feed for FM transmissions, which started in the UK
in 1955.
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
I read somewhere but I don't have a source (though Mark probably
DAB was designed to provide improved reception in moving vehicles and
more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given
that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave
in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll off, -20dB at 6 kHz, -40dB at 7 kHz
Today all AM transmissions will be no better than that, and probably worse.
Back in the 50s/60s I think the BBC used wider bandwidth on 1500m ?
In the US they use 10 kHz channels, and something like 50 kHz separation between channels in a given area (because they've got a bloody huge
country with large distances between major cities) so their bandwidth is
10 kHz (maybe slightly more ?)
I vaguely remember reading that for some places, such as the Royal
Albert Hall, the BBC use to aggregate two or more POTS lines to increase available bandwidth. I could be wrong though, this was in the 1960s.
On 05/01/2023 10:00, Scott wrote:
When did digital start? I would assume 1970s. Before then, would the
signal depend on the length of the PO line, quality of the cable, age
of the cable, design features etc or were they all the same? Would
Brookmans Park have a different arrangement because it is near London
(I believe Crystal Palace has or had).
A lot depended on the equalisation, the GPO sometimes took over
telephone lines to use on an OB and in the days of 405 line, they get a >television down a line for a short distance. I think ITA Winter Hill
had a simple copper pair across the nearby GPO microwave station that
allowed the to monitor the video on the link and I have a feeling it
might have been occasionally used as emergency backup.
On 05/01/2023 12:55, Scott wrote:
On Thu, 5 Jan 2023 12:49:33 +0000, Max Demian <max_demian@bigfoot.com>
wrote:
On 05/01/2023 09:08, Scott wrote:
I am talking about earlier than that. What I read was that
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:What would happen in a situation like that? Does this mean a
were there any "high quality" AM tuners before FM came in?
'European' AM radio does not work in the US because the transmitted
bandwidth is higher?
Take a radio designed for the European market to the US, and the
stations may not sound much better than they do here. (Depends how
tightly the Rx passband is set up) .
If your radio is digitally tuned, it will be useless there anyway,
because the 9 kHz tuning steps won't match the US 10 kHz ones (unless of course the station is on 900 kHz etc)
Some radios (upmarket 'comms' style) are switchable between 9 and 10 kHz
On 05/01/2023 13:29, Scott wrote:
On Thu, 5 Jan 2023 13:01:56 +0000, Mark CarverEven better !
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 12:55, Scott wrote:I have seen one you can change to 1 kHz increments.
On Thu, 5 Jan 2023 12:49:33 +0000, Max Demian <max_demian@bigfoot.com> >>>> wrote:Take a radio designed for the European market to the US, and the
On 05/01/2023 09:08, Scott wrote:What would happen in a situation like that? Does this mean a
On Thu, 5 Jan 2023 08:59:43 +0000, Mark CarverI doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs: >>>>> were there any "high quality" AM tuners before FM came in?
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:I am talking about earlier than that. What I read was that
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR >>>>>>> stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably >>>>>>>> knows) that in the very old days the bandwidth for some AM
I certainly agree with that - especially on DAB that was supposed to >>>>>>>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>>>>>>> of AM in its day - and I mean 'day'Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>>>>>>> more channels.
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>>>>>>> that DAB started at 192 kbps and is now typically 80 kbps, I am >>>>>>>> suggesting that the audio quality could well be worse than medium wave >>>>>>>> in good reception conditions.
off, -20dB at 6 kHz, -40dB at 7 kHz
'unofficially' some BBC Home Service transmitters (where sharing was >>>>>> less of an issue) used up to 15 kHz. This could be urban legend of >>>>>> course, but I will try to find out more.
'European' AM radio does not work in the US because the transmitted
bandwidth is higher?
stations may not sound much better than they do here. (Depends how
tightly the Rx passband is set up) .
If your radio is digitally tuned, it will be useless there anyway,
because the 9 kHz tuning steps won't match the US 10 kHz ones (unless of >>> course the station is on 900 kHz etc)
Some radios (upmarket 'comms' style) are switchable between 9 and 10 kHz
Are you saying that the line to an AM transmitter could be taken over
for television use? Would the radio service have to be suspended or
could a line carry radio and television at the same time?
On 05/01/2023 16:51, Scott wrote:
Are you saying that the line to an AM transmitter could be taken over
for television use? Would the radio service have to be suspended or
could a line carry radio and television at the same time?
In the first days of broadcasting, programme circuits would go from the >studio straight to the transmitter.
But in the 1920s(?) Simultaneous Broadcasting was adopted where all >programmes were fed to a central point then out to all the transmitters.
On 05/01/2023 09:08, Scott wrote:
On Thu, 5 Jan 2023 08:59:43 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:
On 05/01/2023 08:51, Scott wrote:
On Wed, 4 Jan 2023 23:07:51 +0000, MB <MB@nospam.net> wrote:AM channel width in Europe is 9 kHz, the bandwidth in 1974 of ILR
On 04/01/2023 18:41, Scott wrote:I read somewhere but I don't have a source (though Mark probably
I certainly agree with that - especially on DAB that was supposed to >>>>>> offer 'near CD quality' and I would suggest may not meet the quality >>>>>> of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and >>>>> more channels.
knows) that in the very old days the bandwidth for some AM
transmitters could reach about 15 kHz compared with 9 kHz today. Given >>>> that DAB started at 192 kbps and is now typically 80 kbps, I am
suggesting that the audio quality could well be worse than medium wave >>>> in good reception conditions.
stations (source IBA Tech Review 5) was flat to 5 kHz, then a sharp roll >>> off, -20dB at 6 kHz, -40dB at 7 kHz
I am talking about earlier than that. What I read was that
'unofficially' some BBC Home Service transmitters (where sharing was
less of an issue) used up to 15 kHz. This could be urban legend of
course, but I will try to find out more.
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
were there any "high quality" AM tuners before FM came in?
On 05/01/2023 13:14, John Williamson wrote:
On 05/01/2023 12:38, Mark Carver wrote:
I don't think analogue audio circuits for broadcasting have existed for
a long time now, possibly not for 20 years ?
GPO/BT provided a range of guaranteed bandwidths for landlines. However, >>> (and do the maths) the bandwidth of a passive twisted pair bit of copper >>> (which is all an analogue land line ever was) vastly exceeds 15 kHz,
even when it's 'miles' long, it's when it hits some sort of termination >>> device, (telephone, equalising amp etc) that that bandwidth drops.
The other killer though is Group Delay.
I vaguely remember reading that for some places, such as the Royal
Albert Hall, the BBC use to aggregate two or more POTS lines to
increase available bandwidth. I could be wrong though, this was in the
1960s. I suspect mean a stereo matched pair ? (Which were expensive)
I suspect it was a stereo matched pair ?
Didn't the Beeb eventually sick an SHF link on the roof of the RAH, I
think there was a (fortuitous) line of sight with BH's roof ?
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
were there any "high quality" AM tuners before FM came in?
On 04/01/2023 23:07, MB wrote:
On 04/01/2023 18:41, Scott wrote:Using 256k (or above) it could have satisfied both the quality claim,
I certainly agree with that - especially on DAB that was supposed to
offer 'near CD quality' and I would suggest may not meet the quality
of AM in its day - and I mean 'day'
Wasn't that just something said by a journalist.
DAB was designed to provide improved reception in moving vehicles and
more channels.
and the portability claim. And back in the 90s, that was the aim.
With only 5 radio services, 256k per channel was achievable, but from
year 2000 the Beeb added more channels.......
Max Demian <max_demian@bigfoot.com> wrote:
[...]
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
were there any "high quality" AM tuners before FM came in?
There must have been. I have had to transfer a batch of direct-cut
nitrate discs that were recorded from the experimental AM/FM
transmissions from Wrotham. The recording equipment was above reproach
and the quality of all transmissions was extremely good. The dates on
the records confirm that some of the transmissions were AM and very
slight AM-type interference can occasionally be heard.
Max Demian <max_demian@bigfoot.com> wrote:
[...]
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
were there any "high quality" AM tuners before FM came in?
There must have been. I have had to transfer a batch of direct-cut
nitrate discs that were recorded from the experimental AM/FM
transmissions from Wrotham. The recording equipment was above reproach
and the quality of all transmissions was extremely good. The dates on
the records confirm that some of the transmissions were AM and very
slight AM-type interference can occasionally be heard.
Where it all went wrong - for a few weeks until it could be sorted out -
was when an FM tuner with American 75uS de-emphasis was used to receive
the BBC transmissions with 50uS pre-emphasis. I had to de-emphasise and re-emphasise the recordings to get them right. Presumably at that time
there were no British high quality FM tuners available.
In article <1q43rma.1be7ylo177p9fwN%liz@poppyrecords.invalid.invalid>,
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Max Demian <max_demian@bigfoot.com> wrote:
[...]
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs: were there any "high quality" AM tuners before FM came in?
There must have been. I have had to transfer a batch of direct-cut
nitrate discs that were recorded from the experimental AM/FM
transmissions from Wrotham. The recording equipment was above reproach
and the quality of all transmissions was extremely good. The dates on
the records confirm that some of the transmissions were AM and very
slight AM-type interference can occasionally be heard.
Where it all went wrong - for a few weeks until it could be sorted out - was when an FM tuner with American 75uS de-emphasis was used to receive
the BBC transmissions with 50uS pre-emphasis. I had to de-emphasise and re-emphasise the recordings to get them right. Presumably at that time there were no British high quality FM tuners available.
why would there have been with no service for them to use?
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43rma.1be7ylo177p9fwN%liz@poppyrecords.invalid.invalid... > Max
Demian <max_demian@bigfoot.com> wrote: > > [...]
I doubt anyone had radios that could receive 15 kHz. Even Hi-Fi buffs:
were there any "high quality" AM tuners before FM came in?
There must have been. I have had to transfer a batch of direct-cut
nitrate discs that were recorded from the experimental AM/FM
transmissions from Wrotham. The recording equipment was above reproach
and the quality of all transmissions was extremely good. The dates on
the records confirm that some of the transmissions were AM and very
slight AM-type interference can occasionally be heard.
Not quite the same level of vintage but I have some tape recordings of
BBC FM radio from the late 70s and early 1980s, recorded by my
dad - the quality is stunning when compared with today's compressed
and/or processed mess.
charles <charles@candehope.me.uk> wrote:
why would there have been with no service for them to use?
There were quite a few small British manufacturers around who could have quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition continued by Clive Sinclair -- with the exception of the 'working' bit.
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xrb.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...
charles <charles@candehope.me.uk> wrote:
why would there have been with no service for them to use?
There were quite a few small British manufacturers around who could have
quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition
continued by Clive Sinclair -- with the exception of the 'working' bit.
Adoption of FM in general seems to have been very sluggish in the UK.
BBC FM broadcasts began in the 1950s I believe, but it wasn't until
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>There was no 'portability' or mobile requirement for the service when
wrote:
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xrb.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...There must have been a reason. I assume it was either for consistency
charles <charles@candehope.me.uk> wrote:Adoption of FM in general seems to have been very sluggish in the UK.
why would there have been with no service for them to use?There were quite a few small British manufacturers around who could have >>> quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition
continued by Clive Sinclair -- with the exception of the 'working' bit.
BBC FM broadcasts began in the 1950s I believe, but it wasn't until
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xrb.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...
charles <charles@candehope.me.uk> wrote:
why would there have been with no service for them to use?
There were quite a few small British manufacturers around who could have quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition continued by Clive Sinclair -- with the exception of the 'working' bit.
Adoption of FM in general seems to have been very sluggish in the UK.
BBC FM broadcasts began in the 1950s I believe, but it wasn't until
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
There must have been a reason. I assume it was either for consistency
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
There was no 'portability' or mobile requirement for the service when
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the Living
Room sideboard, and (just like the TV) would be fed from a roof top
outdoor aerial.
It's a few decades too late now, but in theory if they'd opted for an
AM broadcast standard in which one of the sidebands was suppressed, >presumably twice the audio bandwidth could have fitted into the same
amount of airspace?
On Thu, 5 Jan 2023 16:20:50 -0000, "Alexander" <none@nowhere.fr>
wrote:
It's a few decades too late now, but in theory if they'd opted for an
AM broadcast standard in which one of the sidebands was suppressed, >>presumably twice the audio bandwidth could have fitted into the same >>amount of airspace?
SSB is routinely used by radio hams where intelligibility of speech is prettty much the only audio quality requirement, but it would be no
good for broadcasting to the public, particularly for music. The
original audio waveform can only be recovered properly if the missing
carier is reinserted in the correct phase in the receiver, a tall
order for domestic equipment, and its typical users.
On 06/01/2023 09:48, Mark Carver wrote:
On 06/01/2023 08:49, Scott wrote:
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
There was no 'portability' or mobile requirement for the service whenAnd FM transmissions were for a long time horizontally polarisedThere must have been a reason. I assume it was either for consistency
for some reason, which made in-car reception impractical.
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the
Living Room sideboard, and (just like the TV) would be fed from a
roof top outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern
for Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf >>
There's always been an argument whether H pol has better immunity to
interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
HP kind of assumes that you're only going to want to receive
transmissions from one direction, in practice one transmitter. All
right when only the BBC was transmitting, but not much good when the commercial stations started broadcasting in FM in the mid 70s.
SSB as you describe (ie. a single sideband only with no carrier)^^^^^^^^
requires precise calibration of a local oscillator (to recreate the
missing sideband basically), otherwise everyone sounds like a Dalek.
On 06/01/2023 08:49, Scott wrote:
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
There was no 'portability' or mobile requirement for the service whenAnd FM transmissions were for a long time horizontally polarisedThere must have been a reason. I assume it was either for consistency
for some reason, which made in-car reception impractical.
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the Living
Room sideboard, and (just like the TV) would be fed from a roof top
outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern for
Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf
There's always been an argument whether H pol has better immunity to interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
On Thu, 5 Jan 2023 16:20:50 -0000, "Alexander" <none@nowhere.fr>
wrote:
It's a few decades too late now, but in theory if they'd opted for an
AM broadcast standard in which one of the sidebands was suppressed, >presumably twice the audio bandwidth could have fitted into the same
amount of airspace?
SSB is routinely used by radio hams where intelligibility of speech is prettty much the only audio quality requirement, but it would be no
good for broadcasting to the public, particularly for music. The
original audio waveform can only be recovered properly if the missing
carier is reinserted in the correct phase in the receiver, a tall
order for domestic equipment, and its typical users.
"Roderick Stewart" <rjfs@escapetime.myzen.co.uk> wrote in message news:7utfrhpcfmn0v05jef8guo7qruqppr1mee@4ax.com...
On Thu, 5 Jan 2023 16:20:50 -0000, "Alexander" <none@nowhere.fr>
wrote:
It's a few decades too late now, but in theory if they'd opted for an
AM broadcast standard in which one of the sidebands was suppressed, >>>presumably twice the audio bandwidth could have fitted into the same >>>amount of airspace?
SSB is routinely used by radio hams where intelligibility of speech is
prettty much the only audio quality requirement, but it would be no
good for broadcasting to the public, particularly for music. The
original audio waveform can only be recovered properly if the missing
carier is reinserted in the correct phase in the receiver, a tall
order for domestic equipment, and its typical users.
I wasn't suggesting an implementation in which they removed the
carrier; rather one in which the carrier and just one sideband
were sent.
SSB as you describe (ie. a single sideband only with no carrier)
requires precise calibration of a local oscillator (to recreate the
missing sideband basically), otherwise everyone sounds like a Dalek.
Most punters would've had no chance of managing this, as you say.
I wasn't suggesting an implementation in which they removed the
carrier; rather one in which the carrier and just one sideband
were sent.
On Fri, 6 Jan 2023 12:13:00 -0000, "Alexander" <none@nowhere.fr>
wrote:
"Roderick Stewart" <rjfs@escapetime.myzen.co.uk> wrote in message news:7utfrhpcfmn0v05jef8guo7qruqppr1mee@4ax.com...
On Thu, 5 Jan 2023 16:20:50 -0000, "Alexander" <none@nowhere.fr>
wrote:
It's a few decades too late now, but in theory if they'd opted for an >>>>AM broadcast standard in which one of the sidebands was suppressed, >>>>presumably twice the audio bandwidth could have fitted into the same >>>>amount of airspace?
SSB is routinely used by radio hams where intelligibility of speech is
prettty much the only audio quality requirement, but it would be no
good for broadcasting to the public, particularly for music. The
original audio waveform can only be recovered properly if the missing
carier is reinserted in the correct phase in the receiver, a tall
order for domestic equipment, and its typical users.
I wasn't suggesting an implementation in which they removed the
carrier; rather one in which the carrier and just one sideband
were sent.
SSB as you describe (ie. a single sideband only with no carrier)
requires precise calibration of a local oscillator (to recreate the >>missing sideband basically), otherwise everyone sounds like a Dalek.
Most punters would've had no chance of managing this, as you say.
That's similar to what they did with the vision signal on analogue television, where they kept the carrier and only removed part of one
of the sidebands. It would have been possible to recreate the video
waveform perfectly by phase locking an oscillator to the carrier and synchronously demodulating the signal, but I think they recognised
that few would want the extra complication (and cost) of circuitry
that would do this (using thermionic valves), which is why they didn't
remove one sideband entirely. An envelope detector (i.e. the usual
simple diode rectifier) would demodulate the low video frequencies
normally, with the higher frequencies at reduced amplitude and with
some phase distortion, but as the high video frequencies only provided
edge detail it was thought that this would be less noticeable. They
got away with it, but it would have introduced horrendous distortion
on an audio signal. Using today's electronics with millions of
transistors on a chip, synchronous demodulation would have been a more feasible option, but we've moved on now, to digital systems with a
whole new set of distortions.
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
b.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xr
charles <charles@candehope.me.uk> wrote:
why would there have been with no service for them to use?
There were quite a few small British manufacturers around who could have >>> quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition
continued by Clive Sinclair -- with the exception of the 'working' bit.
Adoption of FM in general seems to have been very sluggish in the UK.
BBC FM broadcasts began in the 1950s I believe, but it wasn't until
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
There must have been a reason. I assume it was either for consistency
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
In article <a1ofrh1a9a4ruhb8kv4gg6bs449t8kf6a5@4ax.com>, Scott <newsgroups@gefion.myzen.co.uk> scribeth thus
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
b.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xr
charles <charles@candehope.me.uk> wrote:Adoption of FM in general seems to have been very sluggish in the UK.
why would there have been with no service for them to use?
There were quite a few small British manufacturers around who could have >>>> quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition
continued by Clive Sinclair -- with the exception of the 'working' bit. >>>
BBC FM broadcasts began in the 1950s I believe, but it wasn't until
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
There must have been a reason. I assume it was either for consistency
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
IIRC there was some research work done in the very early days and they
found the HP travelled further than VP!
As everyone was to have a rooftop aerial for the hi-fi FM service it
didn't matter, as to cars don't thing there were any around what was it
1955 ish?, With FM receivers!..
Anyone any idea what the situation for FM car radios was in say Europe
or the home of FM in America?..
Anyone any idea what the situation for FM car radios was in say EuropeI think the Americans were big exponents of (true) circular polarization ?
or the home of FM in America?..
On 06/01/2023 08:49, Scott wrote:
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>There was no 'portability' or mobile requirement for the service when
wrote:
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xrb.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...There must have been a reason. I assume it was either for consistency
charles <charles@candehope.me.uk> wrote:BBC FM broadcasts began in the 1950s I believe, but it wasn't until
why would there have been with no service for them to use?There were quite a few small British manufacturers around who could have >>>> quickly brought out a tuner in time for the tests, but they would not
have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if
any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition
continued by Clive Sinclair -- with the exception of the 'working' bit. >>> Adoption of FM in general seems to have been very sluggish in the UK.
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the Living
Room sideboard, and (just like the TV) would be fed from a roof top
outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern for
Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf
There's always been an argument whether H pol has better immunity to >interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
On 06/01/2023 12:26, Max Demian wrote:
On 06/01/2023 09:48, Mark Carver wrote:
On 06/01/2023 08:49, Scott wrote:
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
There was no 'portability' or mobile requirement for the service whenAnd FM transmissions were for a long time horizontally polarisedThere must have been a reason. I assume it was either for consistency >>>> with TV aerials, to reduce interference or to allow directionality of
for some reason, which made in-car reception impractical.
the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the
Living Room sideboard, and (just like the TV) would be fed from a
roof top outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern
for Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf
There's always been an argument whether H pol has better immunity to
interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
HP kind of assumes that you're only going to want to receive
transmissions from one direction, in practice one transmitter. All
right when only the BBC was transmitting, but not much good when the
commercial stations started broadcasting in FM in the mid 70s.
On Fri, 6 Jan 2023 12:30:03 +0000, Mark CarverWell, Clyde used (still does) Black Hill. It was the IBA's main tx site,
<mark.carver@invalid.invalid> wrote:
On 06/01/2023 12:26, Max Demian wrote:Wasn't it the other way round? I thought Radio Clyde (at Blackhill)
On 06/01/2023 09:48, Mark Carver wrote:
On 06/01/2023 08:49, Scott wrote:HP kind of assumes that you're only going to want to receive
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>There was no 'portability' or mobile requirement for the service when
wrote:
And FM transmissions were for a long time horizontally polarisedThere must have been a reason. I assume it was either for consistency >>>>> with TV aerials, to reduce interference or to allow directionality of >>>>> the transmissions. Mark will know :-)
for some reason, which made in-car reception impractical.
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the
Living Room sideboard, and (just like the TV) would be fed from a
roof top outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern
for Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf
There's always been an argument whether H pol has better immunity to
interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
transmissions from one direction, in practice one transmitter. All
right when only the BBC was transmitting, but not much good when the
commercial stations started broadcasting in FM in the mid 70s.
was beamed west towards Glasgow and Radio Forth beamed east towards
Edinburgh precisely to try and contain the signal within the franchise
area.
On Fri, 6 Jan 2023 09:48:28 +0000, Mark CarverRTE have a long history of blasting their TV and FM signals into
<mark.carver@invalid.invalid> wrote:
On 06/01/2023 08:49, Scott wrote:Was this to try and stop the Proddies listening?
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>There was no 'portability' or mobile requirement for the service when
wrote:
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1q43xrb.174k0rw1p46whsN%liz@poppyrecords.invalid.invalid...There must have been a reason. I assume it was either for consistency
charles <charles@candehope.me.uk> wrote:BBC FM broadcasts began in the 1950s I believe, but it wasn't until
why would there have been with no service for them to use?There were quite a few small British manufacturers around who could have >>>>> quickly brought out a tuner in time for the tests, but they would not >>>>> have had the resources or time to develop anything of really high
quality.
A lot of equipment at the time was designed on the principle that if >>>>> any component that could be omitted, it would be - and if the thing
still worked at all after that, that was an added bonus. A tradition >>>>> continued by Clive Sinclair -- with the exception of the 'working' bit. >>>> Adoption of FM in general seems to have been very sluggish in the UK.
the late 1980s that you would find an FM radio fitted as standard
to a typical family car.
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
with TV aerials, to reduce interference or to allow directionality of
the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the Living
Room sideboard, and (just like the TV) would be fed from a roof top
outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern for
Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf >>
There's always been an argument whether H pol has better immunity to
interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
On Fri, 6 Jan 2023 12:30:03 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:
On 06/01/2023 12:26, Max Demian wrote:
On 06/01/2023 09:48, Mark Carver wrote:
On 06/01/2023 08:49, Scott wrote:
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
There was no 'portability' or mobile requirement for the service whenAnd FM transmissions were for a long time horizontally polarisedThere must have been a reason. I assume it was either for
for some reason, which made in-car reception impractical.
consistency with TV aerials, to reduce interference or to allow
directionality of the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the
Living Room sideboard, and (just like the TV) would be fed from a
roof top outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern
for Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf
There's always been an argument whether H pol has better immunity to
interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
HP kind of assumes that you're only going to want to receive
transmissions from one direction, in practice one transmitter. All
right when only the BBC was transmitting, but not much good when the
commercial stations started broadcasting in FM in the mid 70s.
Wasn't it the other way round? I thought Radio Clyde (at Blackhill) was beamed west towards Glasgow and Radio Forth beamed east towards Edinburgh precisely to try and contain the signal within the franchise area.
In article <mkqlrhdfov88j7vgb3h7j299g51obek81e@4ax.com>, Scott ><newsgroups@gefion.myzen.co.uk> wrote:
On Fri, 6 Jan 2023 12:30:03 +0000, Mark Carver
<mark.carver@invalid.invalid> wrote:
On 06/01/2023 12:26, Max Demian wrote:
On 06/01/2023 09:48, Mark Carver wrote:
On 06/01/2023 08:49, Scott wrote:
On Fri, 6 Jan 2023 00:07:07 -0000, "Alexander" <none@nowhere.fr>
wrote:
There was no 'portability' or mobile requirement for the service whenAnd FM transmissions were for a long time horizontally polarisedThere must have been a reason. I assume it was either for
for some reason, which made in-car reception impractical.
consistency with TV aerials, to reduce interference or to allow
directionality of the transmissions. Mark will know :-)
the BBC launched it in 1955.
The expectation was that listeners would have a Tuner, sat on the
Living Room sideboard, and (just like the TV) would be fed from a
roof top outdoor aerial.
Actually, to generate a uniform omni-directional radiation pattern
for Hor Pol is quite tricky, and the Beeb resorted to slot antennas.
Basically a hollow cylindrical tube, with windows
Further reading
http://async.org.uk/Tony.Davies/pubs/ACDavies_FM_in_Britain_for_StP_conf.pdf
There's always been an argument whether H pol has better immunity to
interference than V pol.
RTE in Ireland opted to use V Pol when they launched FM,
HP kind of assumes that you're only going to want to receive
transmissions from one direction, in practice one transmitter. All
right when only the BBC was transmitting, but not much good when the
commercial stations started broadcasting in FM in the mid 70s.
Wasn't it the other way round? I thought Radio Clyde (at Blackhill) was
beamed west towards Glasgow and Radio Forth beamed east towards Edinburgh
precisely to try and contain the signal within the franchise area.
Didn't R Forth use Craigkelly?
And FM transmissions were for a long time horizontally polarised
for some reason, which made in-car reception impractical.
I had crossed dipoles on the van roof.
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