"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, September 27, 2009
The Daventry Story - The World's Largest Shortwave Station
Back in the days when your grandfather was just a young fellow, the chances are that on many occasions, he heard the stentorian voice with a distinct but very clear British accent, declare "This is Daventry Calling," or perhaps, "This is London." Your grandfather may have been twirling the knobs on the family's shortwave receiver, or he may have heard this confidence-building announcement as part of a program relay over his favorite local mediumwave station. But, in any case, that voice was coming from a small studio in London, and the transmitter that carried these words of assurance to the entire world was located at Daventry, right in the very center of the English island. It is a long and highly interesting story, and in Wavescan today we begin with the earlier years at the BBC Daventry.
You will remember that thus far in our five part series on the BBC shortwave station located at Daventry we have presented the story of the original Empire Broadcasts from Gerald Marcuse at his amateur station G2NM followed by the next episode which was a presentation regarding the shortwave station G5SW at its two locations, Chelmsford and then Daventry. Here now, are the beginnings of the BBC's own famous shortwave station located at Daventry.
Actually, the history of Daventry town goes way back to the earliest British villagers, long before the era of the Roman Empire. In the year 51, the Roman army conquered the area and established an encampment at Daventry. Then in the year 1006, the Danes from Denmark attacked the area, and they planted an oak tree to mark the very middle point of England. Hence the name, as they say locally, Dane-Tree, or as we know it on the map of England today, Daventry.
In October, 1931, following a detailed search in several major areas, the administration of the BBC in London finally agreed to establish their large new shortwave station near Daventry, and it would be co-sited with the six year old 25 kW longwave station 5XX. Soon afterwards, plans for this huge new shortwave station were announced. Initially, two STC transmitters rated with an output of 10 to 15 kW would be installed in a new building, together with a total of 18 omni-directional and highly directional antenna systems.
Early in the following year, 1932, international radio monitors in the United States, Australia and New Zealand reported hearing test broadcasts from a shortwave station that announced the callsign G5RX. Initially, some reports conjectured that this series of new test broadcasts was coming from the recently launched passenger liner, "Empress of Britain." Other shortwave listeners said "no," that these test broadcasts were coming from the huge new communication station located at Rugby, and the "Listener-In" radio magazine in Melbourne, Australia reported authoritatively that the callsign G5RX was the experimental test callsign for the BBC's new shortwave station at Daventry.
To make things even more confusing, the regularized callsign GRX, without the number 5 in the middle, was subsequently in use at Daventry for the shortwave channel 9690 kHz. And additionally, Rugby was listed on air experimentally soon afterwards under a G2 callsign (as G2AA), not under a G5 callsign (G5RX).
So, what is the answer? Well, it is known that new phone transmitters were installed at Rugby around the time of the temporary usage of the callsign G5RX, and that sometimes they were testing with program relays. The American radio magazine "Radio News" dated in October 1933 gives us the answer. The temporary callsign was on the air, not at the new BBC Daventry, but at the relatively new GPO station at Rugby, some ten miles to the north west; and for test purposes, Rugby was simply relaying BBC radio programming, taken off air or even off the telephone lines. So, we would suggest, that the "RX" in the callsign G5RX was a sort of radio abbreviation for "Rugby."
In confirmation of this assessment, the same Australian radio magazine, "Listener-In," subsequently tells us that the first test broadcasts from Daventry went on the air under the borrowed callsign G5SW on October 25, 1932, which is some ten months after the tantalizing callsign G5RX was first noted on air.
Anyway, now back to the unfolding story of the BBC shortwave station at Daventry. Test broadcasts began on October 25, 1932, and further tests were noted in mid-November under the now regularized callsign GSE, with the "E" in the callsign standing for "Empire." However, reception reports from several different locations, including Australia, indicated that signal coverage was quite poor and not living up to the previously announced high expectations.
Then, a few days later, on December 19, the BBC began its famous "Empire Service," with the first two hour transmission beginning at 9:00 a.m. and directed to Australia and New Zealand. The production studio for these live broadcasts was located in the new "Broadcasting House" in London and conveyed to Daventry by dedicated telephone lines.
As a historic first, His Majesty, King George V made a radio broadcast on Christmas Day, December 25 in the same year, 1932, and as photos taken at the time reveal, the microphone for this occasion was installed in Buckingham Palace, London. However, to ensure that the programming was indeed heard reliably throughout the world, commercial interests arranged for the shortwave transmitters at Rugby to also relay this programming.
In an endeavor to improve their shortwave service, the BBC refurbished the G5SW transmitter at Chelmsford, re-engineered it to 20 kW, and then re-installed it in the 5GB mediumwave building at Daventry where it was inaugurated on May 19, 1935 as Sender 3. In addition, the BBC announced that two additional high powered shortwave transmitters would be installed at Daventry, with a power rating at 100 kW.
An additional 95 acres adjoining the radio facility at Daventry was purchased, and a new building large enough to hold three transmitters was constructed, the "Empire Service Building." An additional 25 antennas were installed, 14 of which were reversible curtains.
And that's where we leave the story for today; more next week.