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Op 14-6-2025 om 10:36 schreef Liz Tuddenham:
Just a thought:
Now that R4 longwave doesn't have broadcast stations either side of it,
is there any reason it couldn't be used for experimental wide-band
high-quality audio from now until shutdown?
(OK, bandwidth of the links, bandwith of the aerial etc. ...but
wouldn't it be fun!)
It's no use, because most radio's have a lowpass filter built in at
about 5 kHz.
So if you modulate 10 kHz audio, it is surpressed in the receiver.
And then 198 kHz is a relative low carrier frequency compaired to an
audio frequency of 10 kHz, so it costs a lot of extra energy to modulate
10 kHz on 198 kHz
You already mentioned the aerial bandwidth.
In the late 70's Radio Caroline used an Optimod to increase the audio >bandwidth.
I do not remember if it was on1187 kHz or 962 kHz (later 963 kHz).
Because I had a wide AM receiver it sounded wonderful at daytime. But in
the darker period the neighbour transmitters caused extra sounds. The
ship was in the Thames delta, which is further away from The Netherlands >than in the years 72-74.
I am told Caroline used about 6 kHz audio bandwidth.
Rink
Things I recorded in the 1970s, with a dynamic
mike pressed against the TV's speaker, have much
worse line whistle, but that may be induced from
the line coils of the CRT to the coil of the mike
without going via the speaker and "airborne" sound.
That would be AM sound picked up on an FM set
That would be AM sound picked up on an FM set
I seem to remember that it was known as 'slope detection'.
In article <1053u9o$3kqsi$1@dont-email.me>, JMB99 <mb@nospam.net> wrote:
That would be AM sound picked up on an FM set
I seem to remember that it was known as 'slope detection'.
Isn't that the other way round? You tune an ordinary resonant circuit
(as used for AM) so that the FM signal's carrier is on the "slope" of
the circuit's response, so the output depends on the signal's deviation
from the carrier frequency.
-- Richard
In article <1041m9t$3331b$1@dont-email.me>, Rink <rink.hof.haalditmaarwe >g@planet.nl> scribeth thus
Op 14-6-2025 om 10:36 schreef Liz Tuddenham:
Just a thought:
Now that R4 longwave doesn't have broadcast stations either side of it,
is there any reason it couldn't be used for experimental wide-band
high-quality audio from now until shutdown?
(OK, bandwidth of the links, bandwith of the aerial etc. ...but
wouldn't it be fun!)
It's no use, because most radio's have a lowpass filter built in at
about 5 kHz.
So if you modulate 10 kHz audio, it is surpressed in the receiver.
And then 198 kHz is a relative low carrier frequency compaired to an
audio frequency of 10 kHz, so it costs a lot of extra energy to modulate >>10 kHz on 198 kHz
You already mentioned the aerial bandwidth.
In the late 70's Radio Caroline used an Optimod to increase the audio >>bandwidth.
I do not remember if it was on1187 kHz or 962 kHz (later 963 kHz).
Because I had a wide AM receiver it sounded wonderful at daytime. But in >>the darker period the neighbour transmitters caused extra sounds. The
ship was in the Thames delta, which is further away from The Netherlands >>than in the years 72-74.
I am told Caroline used about 6 kHz audio bandwidth.
Rink
Bit late to this post but many years ago i built a TV sound only tuner
for Band 1 and 3 TV.
It was quite surprising just how good the 405 line Amplitude modulated
system was when we were thinking that really quality would be FM only!..
I'm sure I can recall in the distant past picking up TV sound on a
portable FM radio? How could this happen? Harmonics? Faulty TV
somewhere?
On Wed, 2 Jul 2025 00:08:55 +0200, Rink
<rink.hof.haalditmaarweg@planet.nl> wrote:
Op 14-6-2025 om 10:36 schreef Liz Tuddenham:I may have picked this up completely wrongly but I thought I read that
Just a thought:
Now that R4 longwave doesn't have broadcast stations either side of it,
is there any reason it couldn't be used for experimental wide-band
high-quality audio from now until shutdown?
(OK, bandwidth of the links, bandwith of the aerial etc. ...but
wouldn't it be fun!)
It's no use, because most radio's have a lowpass filter built in at
about 5 kHz.
So if you modulate 10 kHz audio, it is surpressed in the receiver.
And then 198 kHz is a relative low carrier frequency compaired to an
audio frequency of 10 kHz, so it costs a lot of extra energy to modulate
10 kHz on 198 kHz
You already mentioned the aerial bandwidth.
In the late 70's Radio Caroline used an Optimod to increase the audio
bandwidth.
I do not remember if it was on1187 kHz or 962 kHz (later 963 kHz).
Because I had a wide AM receiver it sounded wonderful at daytime. But in
the darker period the neighbour transmitters caused extra sounds. The
ship was in the Thames delta, which is further away from The Netherlands
than in the years 72-74.
I am told Caroline used about 6 kHz audio bandwidth.
the BBC used up to 15 kHz on some Home Service transmitters where the frequency was not shared (in the UK) and there were no complaints from overseas.
I never heard an official landbased AM station with such high audio frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became
Radio 2), and I did not have a radio in 1967...
FM sets were often not immune to AM; I remember people picking up police
(or something like that) AM when it was still in the top of Band II
(Was it 100 rather than 108 MHz that was the nominal top of Band II
for the UK initially?)
(Was it 100 rather than 108 MHz that was the nominal top of Band IIIt was 98 I believe.
for the UK initially?)
On 17/07/2025 14:39, Rink wrote:
I never heard an official landbased AM station with such high audio
frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became
Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2.
On 17/07/2025 14:39, Rink wrote:
I never heard an official landbased AM station with such high audio
frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became
Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2.
On 17/07/2025 15:21, The Other John wrote:
On 17/07/2025 14:39, Rink wrote:Also, the Light Programme was on 1500 metres Long wave, and the Home
I never heard an official landbased AM station with such high audio
frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became
Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2.
service was on a number of medium wave frequencies. The two swapped frequencies when they changed the names. Radio 4 got long wave and Radio
2 got medium.
On 2025/7/31 15:41:29, John Williamson wrote:
On 17/07/2025 15:21, The Other John wrote:I'm pretty sure the changes weren't on the same date: I don't remember hearing the Home Service or Light (or Third) Programme, but I'm pretty
On 17/07/2025 14:39, Rink wrote:Also, the Light Programme was on 1500 metres Long wave, and the Home
I never heard an official landbased AM station with such high audio
frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became >>>> Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2.
service was on a number of medium wave frequencies. The two swapped
frequencies when they changed the names. Radio 4 got long wave and Radio
2 got medium.
sure I remember Radio 2 being on long wave.
On 31/07/2025 16:38, J. P. Gilliver wrote:
On 2025/7/31 15:41:29, John Williamson wrote:I wasn't 100% certain of the date of the swap, to be honest. I just
On 17/07/2025 15:21, The Other John wrote:I'm pretty sure the changes weren't on the same date: I don't remember
On 17/07/2025 14:39, Rink wrote:Also, the Light Programme was on 1500 metres Long wave, and the Home
I never heard an official landbased AM station with such high audio
frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became >>>>> Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2. >>>>
service was on a number of medium wave frequencies. The two swapped
frequencies when they changed the names. Radio 4 got long wave and Radio >>> 2 got medium.
hearing the Home Service or Light (or Third) Programme, but I'm pretty
sure I remember Radio 2 being on long wave.
remember Mum having to retune her radio and being miffed.
On 2025/7/31 15:41:29, John Williamson wrote:
On 17/07/2025 15:21, The Other John wrote:I'm pretty sure the changes weren't on the same date: I don't remember hearing the Home Service or Light (or Third) Programme, but I'm pretty
On 17/07/2025 14:39, Rink wrote:Also, the Light Programme was on 1500 metres Long wave, and the Home
I never heard an official landbased AM station with such high audio
frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became >>>> Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2.
service was on a number of medium wave frequencies. The two swapped
frequencies when they changed the names. Radio 4 got long wave and Radio
2 got medium.
sure I remember Radio 2 being on long wave.
I thought these changes took place in 1978 when R1 moved from 247m to 275/285m, R2 moved from 1500m to 433/330m, R3 from 648m to 247m and R4
from regional medium wave frequencies (England) to 1500m.
(Jingle) '275 and 285, 275 and 285, we're on a new wave band, still
the best in the land'
On Thu, 31 Jul 2025 16:51:42 +0100, John Williamson <johnwilliamson@btinternet.com> wrote:
On 31/07/2025 16:38, J. P. Gilliver wrote:
On 2025/7/31 15:41:29, John Williamson wrote:I wasn't 100% certain of the date of the swap, to be honest. I just
On 17/07/2025 15:21, The Other John wrote:I'm pretty sure the changes weren't on the same date: I don't remember
On 17/07/2025 14:39, Rink wrote:Also, the Light Programme was on 1500 metres Long wave, and the Home
I never heard an official landbased AM station with such high audio >>>>>> frequencies.
But I must say: as far as I know Home Service ended in 1967 (it became >>>>>> Radio 2), and I did not have a radio in 1967...
The Home Service became Radio 4 and The Light Programme became Radio 2. >>>>>
service was on a number of medium wave frequencies. The two swapped
frequencies when they changed the names. Radio 4 got long wave and Radio >>>> 2 got medium.
hearing the Home Service or Light (or Third) Programme, but I'm pretty
sure I remember Radio 2 being on long wave.
remember Mum having to retune her radio and being miffed.
I thought these changes took place in 1978 when R1 moved from 247m to 275/285m, R2 moved from 1500m to 433/330m, R3 from 648m to 247m and R4
from regional medium wave frequencies (England) to 1500m.
(Jingle) '275 and 285, 275 and 285, we're on a new wave band, still
the best in the land'
On 31/07/2025 17:09, Scott wrote:
I thought these changes took place in 1978 when R1 moved from 247m to
275/285m, R2 moved from 1500m to 433/330m, R3 from 648m to 247m and R4
from regional medium wave frequencies (England) to 1500m.
(Jingle) '275 and 285, 275 and 285, we're on a new wave band, still
the best in the land'
As a matter of interest, when UK radio stations start quoting their frequency rather than their wavelength? My parents' Grundig Yacht Boy
radio which they bought some time in the late 1960s, has MW marked in
kHz (now I've finally managed to find an online photo that shows the
scale in enough detail!) I think LW is also in kHz: it shows BBC Radio 2 against a three-digit (200 kHz) rather than four-digit (1500 m) number.
So it looks as at least for a German market, frequency was used from a
long time ago.
On 2025/7/31 18:44:22, NY wrote:
On 31/07/2025 17:09, Scott wrote:
I thought these changes took place in 1978 when R1 moved from 247m to
275/285m, R2 moved from 1500m to 433/330m, R3 from 648m to 247m and R4
from regional medium wave frequencies (England) to 1500m.
(Jingle) '275 and 285, 275 and 285, we're on a new wave band, still
the best in the land'
As a matter of interest, when UK radio stations start quoting their
frequency rather than their wavelength? My parents' Grundig Yacht Boy
Ah yes, the Boys. Grundig had a range of those, Yacht Boy being one of
them. My friend Len at work (Communications department, Marconi Research >Centre, as it was then) called one of his prototypes Call Girl, in response.
radio which they bought some time in the late 1960s, has MW marked in
kHz (now I've finally managed to find an online photo that shows the
scale in enough detail!) I think LW is also in kHz: it shows BBC Radio 2
against a three-digit (200 kHz) rather than four-digit (1500 m) number.
So it looks as at least for a German market, frequency was used from a
long time ago.
Yes, I had that feeling - possibly most of contiguous western Europe.
Was band II - or FM - and above, _ever_ referred to in metres (or cm)? I >never heard it/them so, except in the _names_ of the bands in amateur >circles (the 2m, 70cm, and IIRR 23cm bands [but AFAICR amateurs always >referred to the _frequency_ they were on within those bands]). I
certainly _never_ heard or saw anyone referring to a band II station
being on so many metres.
Come to think of it, I also have a _vague_ memory of Band II having--- Synchronet 3.21a-Linux NewsLink 1.2
channel numbers on some sets (as well as the MHz) - but I don't remember >anyone ever _using_ those.
On Fri, 1 Aug 2025 05:58:54 +0100, "J. P. Gilliver" <G6JPG@255soft.uk>
wrote:
Was band II - or FM - and above, _ever_ referred to in metres (or cm)? I
never heard it/them so, except in the _names_ of the bands in amateur
circles (the 2m, 70cm, and IIRR 23cm bands [but AFAICR amateurs always
referred to the _frequency_ they were on within those bands]). I
certainly _never_ heard or saw anyone referring to a band II station
being on so many metres.
Did one of the DJs do it for fun - maybe Kenny Everett or Steve
Wright?
--Come to think of it, I also have a _vague_ memory of Band II having
channel numbers on some sets (as well as the MHz) - but I don't remember
anyone ever _using_ those.