"Wavescan" is a weekly program for long distance radio hobbyists produced by Dr. Adrian M. Peterson, Coordinator of International Relations for Adventist World Radio. AWR carries the program over many of its stations (including shortwave). Adrian Peterson is a highly regarded DXer and radio historian, and often includes features on radio history in his program. We are reproducing those features below, with Dr. Peterson's permission and assistance.
Wavescan 491, May 30, 2004
Quite recently, a radio friend in England made available to "Wavescan" a very interesting QSL card. This card verified a reception report dated April 29 in the year 2000 and it was issued by "Portishead Radio".
The interesting fact that was printed on this QSL card states that the station claimed to be the largest radio communication centre in the world. And so today here in Wavescan, we take a look at this interesting radio communication station.
It was back in the year 1920 that their first maritime transmitting and receiving facility was installed into an old wireless receiving station at a coastal location near Devizes in county Wiltshire on the west coast of England. This station was their first long range maritime transmitting station, and the single transmitter was a 6 kw valve unit operating on longwave under the callsign GKT.
Four years later, a second longwave transmitter was installed at this same Devizes location. It was also in this same year that a receiving station was installed at Highbridge and this location became the control centre for Portishead Radio for the lengthy period of sixty years.
In the year 1926, the first shortwave transmitter was installed into the original site at Devizes, and this marked an important turning point in international radio communication.
A new facility was constructed at Portishead near Bristol in 1927, and this station was officially opened on July 1, 1928. From this time onwards, regardless of the actual transmitter location, the facility was always known as "Portishead Radio."
Initially, Portishead itself contained three longwave transmitters, though a new shortwave transmitter was installed in 1929. It was at this stage that the original facility at Devizes was closed. Subsequently, three new shortwave transmitters were installed at this location, and the longwave units were withdrawn from service.
During the war years, beginning in 1939, Portishead introduced one way transmissions for shipping in the Atlantic as a security measure.
Over the years, Portishead Radio underwent many major developments that included the usage of several additional transmitting locations. In fact, one of their QSL cards lists about a dozen transmitter sites that were in use for varying periods of time.
In the year 1948, the transmitter site at Portishead was closed, leaving just three active sites on the air, Leafield, Ongar and Rugby. The Rugby facility was a famous early radio station that was constructed by the Post Office, and it was on the air mainly with international communication traffic. There were times, though, when Rugby was brought into use for the broadcast of radio programming from the BBC London.
The callsign range for Portishead Radio began with GKA, and it seems that every letter of the alphabet was in use at some time or another, right down to GKZ.
The usage of Morse Code was gradually phased out over a period
of time, until in 1999 almost all communications were in voice
mode or with electronic signaling. The final transmission
from Portishead Radio, using the Post Office transmitter at Rugby,
was on April 30, 2000 in Morse Code.
Even though Portishead Radio was a communication station and not a program broadcasting station, yet they were known as a reliable verifier during their more than 80 years of on-air service. The AWR collection contains a nice range of Portishead QSL cards in three different styles.
The nicest card was their yellow and blue global card identifying their initial callsign, GKA. A later card was a white text card identifying the next sequential callsign GKB. Their final card was a photo folder card, also identifying the callsign GKB.
The 75th anniversary brochure issued by Portishead Radio in 1995 makes this statement: Portishead Radio is the most famous maritime station in the world. Their final QSL card in April 2000 makes this statement: Portishead Radio was the largest radio communication station in the world.
In view of their long 80 years of service, and the fact that they were on the air from maybe even more than a dozen different transmitter locations, it would seem then that their twin claims to importance and size were indeed quite accurate.