IBA map for ILR Bury St Edmunds (Saxon Radio / SGR etc)
Classic Gold Amber now named Gold.
++ No coverage map yet available
The IBA carried out some tests with AM stereo from the Foxhall Heath transmitter and were to assess the compatibility with current AM receivers and the interaction with other 'ordinary' AM transmissions. As far as I can remember these tests were conducted in the mid 1980's and only the Radio Orwell MW transmitter was used, no other ILR AM transmitters were involved. The tests lasted for a matter of weeks and hopes were raised that AM stereo would be generally adopted by ILR in the not too distant future.
The system used for the tests was the American CQuam (Compatible Quadrature AM) system which had been developed by Motorola. The tests were apparently successful, but it seems that the government of the day were indifferent to the benefits that it may offer and were unwilling to allow further tests from other sites and thus the general adoption of AM stereo was ruled out.
The CQuam AM Stereo system was widely adopted by AM radio stations in North America and is still in use today, although the number of AM stations transmitting music has dwindled.
This system transmits stereo by using 2 phases of the RF carrier 90 degrees apart. Each phase of the carrier is fed to a balanced modulator. The balanced modulator that is in phase with the original RF signal receives left plus right mono audio. The balanced modulator that is 90 degrees out of phase receives the left minus right stereo information. The balanced modulator outputs are summed together with the original in phase carrier and then passed through a limiter so only the phase information is retained. This signal is then modulated by the conventional means in the transmitter, producing a quadrature AM signal that is compatible with mono AM radios. Stereo identification is provided by a 25 Hz pilot tone transmitted in with the left minus right information. This system may be decoded using a chip like the Motorola MC13020P.
More information on the subject of AM Stereo can be found here: http://www.wa2fnq.hamradios.com/amstrdoc.htm
|ILR GREAT YARMOUTH, LOWESTOFT AND
A later addition to the commercial air-waves of Suffolk is ILR Lowestoft and Great Yarmouth (103.4 The Beach etc.).
This ILR station originally transmitted from a single 2kW v.h.f. / FM transmitter at Oulton in Lowestoft which serves Lowestoft, Great Yarmouth, Beccles, Bungay and Caister on Sea.
The Radio Authority (now Ofcom) later advertised for an company to operate a small scale, stand-alone, ILR station for the Southwold area, but no suitable applicant was found and the offer of a licence was withdrawn.
The current holder of the ILR Lowestoft and Great Yarmouth licence (103.4 The Beach) has now been allowed to add a 0.24 kW relay station located at Blythburgh to serve Southwold and the surrounding area, this opened in May 2004. Presumably this is the frequency originally intended for the stand-alone ILR Southwold station.
|Map of ILR Lowestoft and Great
Yarmouth with Southwold
|RadioMobile pixel plot for the
additional 0.24 kW FM relay at Blythburgh
For ILR Lowestoft and Gt. Yarmouth with Southwold
|FM 103.4 The Beach also released
this map for their new Blythburgh transmitter:
Relay station for ILR Southwold - 97.4 FM
Coverage map for the Southwold community radio station
Blyth Valley Radio 105.0 FM
|ORFORDNESS - VT Merlin Transmitting
Here's an odd one. The major transmitting station at Orfordness was once owned by the BBC as part of its transmitter network used for the BBC World Service. Transmissions were broadcast on 648 kHz and 1296 kHz.
The BBC transmitter network was priviatised and sold off in 1997 to Merlin Communications International, subsequently re-organised and re-named VT Merlin when it was acquired by the Vosper Thornycroft Group p.l.c.
The VT Merlin site at Orfordness continued a contract with the BBC World Service transmitting the programmes to Europe on 648 kHz until transmissions ceased for good in spring 2011.
In 2004 the 1296 kHz transmitter was contracted for a period to transmit the programmes of Radio Nationaal of The Netherlands.
On 15th July 2011 after a fire in the transmitter tower/mast at Hoogersmilde in The Netherlands the mast section collapsed. Hoogersmilde was constructed as an 82 metre high concrete tower with a guyed cylindrical mast section on top. The total height being 294 metres. Construction was similar to the Gerbrandytoren in Lopik sites. At 13:50 a fire was reported, the cause was unknown. At 15:39 the mast part collapsed. All radio and TV across the region was taken off the air.
Some reception was restored to the area affected by the transmission engineers by installing temporary transmitting equipment at different sites. However signal strength was weaker and reception patchy in places. As part of the plan to restore radio to the area the Dutch authorities hired the 648kHz transmitter in Orfordness, UK, to transmit programmes to the Netherlands at good signal strengths. This arrangement would bring radio to the Netherlands for some months, until more satisfactory local arrangements could be made to restore reception.
Once the exercise was completed the Orfordness station fell into disuse once again.
|The Coverage Map
Of 1296 kHz From Orfordness
More About Hoogersmilde - from Koos van den Hout
A major transmitting tower for the north(eastern) part of the country.
Dutch public broadcasters (NL1/2/3, regional TV) and 4 other (encrypted) multiplexes for digitenne service
FM radio public services (Radio 1,2,3,4, Radio Drenthe)
FM radio commercial: Skyradio, Q music, Slamfm, Veronica, Benelux news Radio, 100% NL, RadioNL, Arrow classick rock.
As the Hoogersmilde transmission tower caught fire and collapsed, the power was cut off to (part of the normal fire department attack methods) but emergency power generators took over. The antenna feedline cables hanging down from ~ 90 meters were smouldering with RF energy.
Radio 1 (news station in the public radio landscape) started using its old AM frequency again: 747 kHz (normally used by radio 5) which comes from the AM transmitters in Zeewolde. Transmissions of Radio 1 FM also continued from Hilversum (north of the middle of the country) and Tjerkgaast (Friesland, northern province).
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