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3rd Feb 2015, 12:35 am | #1 |
Retired Dormant Member
Join Date: Apr 2003
Location: Salt Spring Island, BC, Canada
Posts: 368
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Famous European AM stations
For interesting histories of some of the main AM stations go to:
https://goodbyeam.worldpress.com/page/9/ I was interested to learn that in WW2, the BBC syncronised the frequency of several stations in different parts of the country to prevent them being used by the enemy for DF navigation. The BBC also assisted Radio Athlone in setting up relay stations on the same frequency in the North of England and in Scotland for the same purpose. Latter Radio Athlone was syncronised with stations in Dublin and Cork for the same reason. John. |
3rd Feb 2015, 12:50 am | #2 |
Retired Dormant Member
Join Date: Apr 2003
Location: Salt Spring Island, BC, Canada
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Re: famous European AM stations
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3rd Feb 2015, 1:03 am | #3 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
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Re: famous European AM stations
The BBC networks were all synchronised until privatisation of the transmission network about 20 years ago.
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3rd Feb 2015, 1:04 am | #4 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
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Re: famous European AM stations
https://goodbyeam.wordpress.com
I could not get the links to work, the above link works on my computer. Frank |
3rd Feb 2015, 3:28 am | #5 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
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Re: famous European AM stations
Yes, that one is OK, ignore the links in the earlier posts.
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3rd Feb 2015, 11:45 am | #6 |
Pentode
Join Date: Jul 2009
Location: Hucknall, Nottinghamshire, UK.
Posts: 223
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Re: famous European AM stations
Thanks for the link, I'm finding it interesting..
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5th Feb 2015, 9:36 pm | #7 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
Posts: 2,801
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Re: famous European AM stations
The synchro bit used the telephone network. Amazingly the same network was later used to provide national uk syncs for BBC1 network programs e.g. "Nationwide", although failures did occur.
Radio 1 was synchro on 1214, although not in sync with Radio Tirana in the background! |
5th Feb 2015, 9:54 pm | #8 |
Pentode
Join Date: Jul 2009
Location: Hucknall, Nottinghamshire, UK.
Posts: 223
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Re: famous European AM stations
Here in Nottingham area we were in a R1 mush zone, I presume that Droitwich & Moorside Edge came in about equal strength & caused fading & distortion. Problem was solved when R1 went to 275/285 metres in the late 70's, Droitwich 285 metres was perfect with no fading or distortion. 275 still had distortion & fading, I presume it was Moorside Edge & Brookmans Park interfering with each other..
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5th Feb 2015, 11:15 pm | #9 |
Octode
Join Date: Jan 2013
Location: Barnsley, South Yorkshire, UK.
Posts: 1,517
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Re: famous European AM stations
In the early years of the 'tone lock' system there was an effect called 'door bang'. Because the tone was multiplied up at the transmitter to provide the carrier reference, if there was phase jitter on the phone circuit over which the tone was being sent the phase multiplied up was a frequency shift. This pulled the transmitter off frequency and back over a split second; the effect, on a listener's receiver, sounded like a banging door!
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6th Feb 2015, 12:19 am | #10 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
Posts: 2,801
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Re: famous European AM stations
The problems affecting R1 became those of R3 when it moved to 1215. There was a brief period when two different transmitters carried R4 and WS (probably Crowborough) very late at night on 1457 - this ended when R4 Midlands left 1052 (there was a taped loop message) and WS took it up. European Service also had 1088 at the same time as R4 Scotland back in the 70's. After 1978, there were plenty of R1 mush zones on 1053 and 1089 especially on a car radio in the south here.
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6th Feb 2015, 9:05 am | #11 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Re: famous European AM stations
I seem to recall from my Crowsley Park days tbat synch group tolerance was +/- 0.05 Hz for BBC national networks, +/- 0.1Hz for non-synch ... Ian (G4JQT), can you confirm/edit?
[ Radio Tirana ... +/- a lot more. "Na-na-nee-na na-na .. naa .. naa" ] Best wishes Guy
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6th Feb 2015, 10:50 am | #12 |
Octode
Join Date: Jun 2004
Location: Reading/Fakenham, UK.
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Re: famous European AM stations
Yes, that seems correct, although the BBC had one local station (Radio Derby?) that drifted/cycled something like +2/-5 Hz for years and years.
A colleague said the 0.05 Hz was arrived at after listening tests deemed that most people could tolerate a distorting fade every 20 seconds or so, that lasted only a few seconds, and it wasn't too technically difficult to achieve. On the other hand some pirate ship stations had a deliberate offset of about 30 Hz which was ok because the beat was too low to be reproduced by most radios' speakers. They couldn't achieve the 0.05 Hz tolerance anyway, even if the foreign co-channel station could, so a deliberate 'inaudible' 30 Hz offset was a good compromise! I think the international limit is meant to be +/- 5 Hz, or maybe it's +/- 10 Hz. That's certainly what my Ofcom RSL transmitters are required to keep to. Regards, Ian Last edited by Ian - G4JQT; 6th Feb 2015 at 10:59 am. |
9th Feb 2015, 2:45 am | #13 |
Retired Dormant Member
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Re: Famous European AM stations
Radio 1 reception was always better on 1089 I think but even this was awful at night, lots of fading and interference once it started to get dark. This was high up on the Eastern edge of Leicester. Stations from all over western Europe came in well at night, I often listened to YLE and other stations from the northern countries, Radio Moscow and French/German stations also provided good evening listening.
Lazer 558 and Atlantic 252 were favourites for music and the latter always provided good (enough) reception, even at night. Brian |
9th Feb 2015, 6:23 pm | #14 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
Posts: 2,801
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Re: Famous European AM stations
As a keen DXer in the 80's and 90's, the following offered excellent English language
programmes with very strong signals; Sweden 1179 kHz Norway 1314 kHz (sunday only) Belgium 1512 kHz All had programmes for DXers |
11th Feb 2015, 9:07 pm | #15 |
Hexode
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
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Re: Famous European AM stations
I remember all those stations. I also remember that radio Moscow had a DX show as well. I lived in Newbury in Berkshire then and radio 1 suffered from phase distortion on both 275 and 285 meters even inthe day there was a little fading evident. I remember in the winter evenings I could here the Albanian transmitter at Durres on 1089khz burbling away under radio one this tx I believe was only 150 kW yet still audible here.
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