 |
| Transmitters of Daventry |
Special thank you to Ray Robinson, Dr Adrian Peterson, and Jeff White, for sharing this week's episode - next week will feature part 2
Jeff: Those of you who collect antique radios, particularly ones made in Europe, may have noticed stations marked on the dial often included one called “Daventry”. Well, as we mentioned last week, we are now going to present the story of that major BBC transmitting station at Daventry in England. The story begins with the launch of the BBC Empire Service in 1932. Here’s Ray Robinson.
Ray: Thanks, Jeff. Daventry is a small town located in the English Midlands about 40 miles southeast of Birmingham. The history of the town goes way back even before the era of the Roman Empire. In the year 51 AD, the Roman army conquered the area and established an encampment at the village which already existed there. Then in the year 1006, Danish invaders attacked the area, and they planted an oak tree to mark the exact center of England. Hence the name, as they say locally, Dane-Tree, or as we know it on the map of England today, Daventry.
The BBC facility was established just outside the town at a location called Borough Hill, and the first transmitter to be activated there was actually a shortwave one that had been previously licensed at the Marconi factory in Chelmsford as G5SW, and which remained in service for an incredible 32 years.
By the mid-1920’s, the use of shortwave transmissions for international communication as well as for program broadcasting was already proving to be quite successful. Guglielmo Marconi himself had performed several successful long-range tests, and experimental shortwave broadcasting was already on the air from stations in the United States and Australia, as well as from amateur operators in England itself.
With this in mind, Marconi constructed a 10 kW shortwave transmitter in 1927, and the first broadcast transmission from the new unit took place on Armistice Day 1927. This inaugural broadcast on November 11 commemorated the end of what we now call World War I, and the programming was shaped to honor this occasion.
This new shortwave transmitter was hurriedly assembled from already available equipment and the two aerial masts, 475 ft. high, supported an aerial that was omni-directional and vertically polarized. The original channel was around 12500 kHz, though this was changed in the following year to 11750 kHz in accordance with new regulations enacted at the 1927 International Radiotelegraph Conference in Washington, D.C.
Thus began a regular international radio broadcasting service that was heard around the world, and which was reported quite frequently in radio magazines published in England, the United States, Australia and New Zealand. Programming for this shortwave broadcasting service was usually a relay from 2LO in London, and these shortwave transmissions from Chelmsford were on the air for a little over three years.
The BBC then made arrangements with Marconi to rent the shortwave transmitter at Chelmsford to provide a preliminary program service while their own large station at Daventry was under construction. The BBC took over the programming for shortwave G5SW in 1931, and on January 5, 1932, the BBC used it to introduce their new expanded Empire Service.
It was in October 1931 that the BBC had decided to establish their own large new shortwave station near Daventry, and they co-sited it with the six year old 25 kW longwave station 5XX. The initial plans called for two STC transmitters rated at 10 to 15 kW to be installed in a new building, together with a total of 18 antenna systems, both directional and omni-directional.
While the Daventry site was being built, early the following year, in 1932, radio monitors in the USA, Australia and New Zealand reported hearing test broadcasts from a shortwave station that announced the callsign G5RX. These originated from a new GPO site at Rugby, only 10 miles from Daventry. Rugby was primarily a communication station, but some phone-capable transmitters had been installed, and these were being tested.
Ten months later on October 25, 1932, just a year after the BBC’s plans had been announced, the first tests were heard from the two new STC transmitters at Daventry, designated as Sender 1 and Sender 2. Interestingly, they used the same Chelmsford callsign G5SW – all while the Marconi transmitter G5SW was still located at Chelmsford, 100 miles away.
By mid-November, more tests were heard under the now regularized callsign GSE, with the “E” in the callsign standing for “Empire”. As you might expect, though, from 10-15 kW units, signal strength as received in Australia was not good, and the transmissions did not initially live up to the previously announced high expectations. Regardless, the five-year-old Marconi transmitter in Chelmsford was closed down on December 17, 1932 in favor of the two new transmitters located at Daventry, and then two days later on Monday, December 19, the BBC began its famous “Empire Service”. The first two-hour transmission began at 9:30 am UK time, introduced by announcer William Shewen. J.H. Whitley, Chairman of the BBC and Director General Sir John Reith both participated, explaining their aspirations for the new service. It was directed primarily towards Australia and New Zealand, with Sender 1 using the callsign GSC on 9585 kHz, and Sender 2 using GSD on 11750 kHz. This is how the broadcast began:
Additional information and videos on Daventry are available for a search at www.youtube.com
The production studio for those live broadcasts was in the new “Broadcasting House” in London, with a program feed to Daventry via dedicated telephone lines.
 |
| Sir John Reith and Rt. Hon. J.H. Witley |
As a historic first, His Majesty, King George 5 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 the King’s Speech was heard reliably throughout the world, arrangements were made for it also to be relayed via the shortwave transmitters at Rugby.
In January 1935, the Marconi transmitter, which by then had been off the air for two years, was refurbished and re-engineered up to 20 kW, with the capability of operating on several different shortwave bands. It was then transferred to Daventry, and installed in an available open space in what was known as the 5GB Medium Wave Building. At this new BBC location, the historic Marconi transmitter was designated as Sender 3 (the two STC units being Sender 1 and Sender 2) and it was brought back into regular broadcast service on May 19, 1935. Callsigns used by this transmitter now depended on what frequency was in use, with a different callsign for each waveband. At the same time, the BBC announced that two additional high-powered shortwave transmitters would be installed at Daventry, with a power rating of 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.
In 1937, the former Marconi transmitter was upgraded again, this time to 60 kW.
During the intense events of 1940 with the Allied Expeditionary Force in northern France, Sender 3 was used for carrying the Forces Program on 6150 kHz.
However, as time went by, this historic transmitter became increasingly unreliable, and ultimately, it was withdrawn from service and removed from the 5GB Building in 1959. We assume at that point, it was simply scrapped.
And we’ll continue the BBC Daventry story next week. Back to you, Jeff.
(Ray Robinson/Wavescan)
