"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, December 29, 2013
Focus on Africa: The BBC Central Africa Relay Station, BBC Francistown
On a previous occasion here in Wavescan, we presented the story of early shortwave broadcasting in Bechuanaland, or Botswana as it is known today, under the title, The Torn QSL Card. That was the story of the unique communication station ZNB that was located near Mafeking in South Africa, close to the border with Bechuanaland and it was in use also for the broadcast of informational and entertainment radio programming.
In our program today, we follow up in these matters in Bechuanaland/Botswana, and we present the story of the temporary relay station that was installed for the BBC near Francistown, which was located within Bechuanaland itself. This is what happened.
Back in the colonial days, the influential political leader Cecil Rhodes established a British territory in southern Africa which was named in his honor as Rhodesia in 1895. In the convoluted politics of the time, ultimately two Rhodesias emerged; Northern Rhodesia which later became Zambia and Southern Rhodesia which later became Zimbabwe.
On November 11, 1965, the territory of Southern Rhodesia, under the individual name of just Rhodesia, made a unilateral declaration of independence from British oversight with Ian Smith as the Prime Minister. At the same time, the Rhodesia Broadcasting Corporation dropped the relay of all BBC programming on its national network of mediumwave and shortwave broadcasting stations.
It was at this stage that the British government hurriedly laid plans for the installation nearby of a mediumwave and shortwave station for the relay of BBC programming beamed specifically into Rhodesia. A site was chosen just outside Francistown in neighboring Bechuanaland, just 16 miles from the border with Rhodesia.
The town of Francistown was named in honor of an English gold prospector, Daniel Francis, in 1897. These days, Francistown is the second largest city in Botswana with a total population reaching towards 1/4 million. It is located in a very dry area and weather reports indicate that during some eras no rain has fallen for several years in a row.
When the political crisis unfolded in Rhodesia at the end of the year 1965, the BBC did a quick search for available transmitters and they settled on Continental in Dallas, Texas for two mediumwave units. It so happened that Continental was constructing several 50 kW mediumwave transmitters at the time, Model 317C, for various clients, one of whom was Ronan O'Rahilly who was operating the British pirate station "Radio Caroline" aboard the radio ship "Mi Amigo".
Entrepreneur O"Rahilly agreed to allow the BBC to take the Continental 50 kW mediumwave transmitter 317C No. 12 that he had ordered and this was flown over to Francistown in Africa and installed at the new BBC Central Africa Relay Station. The next Continental transmitter Model No. 13 was also taken over by the BBC and installed in their new Francistown radio station.
Transmitter No. 12, 50 kW Continental 317C, was inaugurated at the new BBC mediumwave relay station on December 30 1965; and transmitter No. 13 was inaugurated a few weeks later, early in the New Year 1966.
Interestingly, O"Rahilly with Radio Caroline then took transmitter No. 14 and he installed it on board the "Mi Amigo," and when that ship sank in the Thames Estuary out from London 15 years later, the transmitter went down also. It is still there to this day, at the shallow bottom of the North Sea!
The BBC Central Africa Relay Station was quickly constructed under the supervision of Harold Robin who earlier achieved fame when he supervised the installation of the American super high powered mediumwave transmitter "Aspidistra" at Crowborough in Sussex, England during World War 2. A total of 60 tons of radio equipment was flown in from the United States and England for installation at Francistown, and 18 support technicians installed the equipment.
This station, planned from the beginning as a temporary facility, was located on an almost barren 100 acre property just outside the edge of Francistown. It was operated by DWS, the British Diplomatic Wireless Service, and programming was entirely in English; either the BBC World Service, their regular services to Africa, or special programming specifically tailored for Rhodesia.
Some pre-recorded programming was prepared in advance by the BBC Transcription Service and flown in to Francistown from England. It would be presumed that the live program feed came in on shortwave, probably via Daventry in England and via the BBC relay station on the island of Cyprus in the Mediterranean. At the height of its service, the BBC African Relay Station was on the air with four transmitters in parallel for a total of 15 hours daily.
In order to prevent listeners within Rhodesia itself from hearing the programming from the BBC Francistown, the Rhodesian government activated jamming transmitters at several different locations on March 21, 1966, though the main jammers were installed at Salisbury and Bulawayo. However, as an economy measure, the Rhodesian jammers were activated only when the BBC station presented information about Rhodesia itself. Rhodesian jamming against the two mediumwave channels was at times rather successful, though jamming against the shortwave transmissions was not so effective.
The two shortwave transmitters in use at BBC Francistown were 10 kW Marconi units from England. The first of these was taken into service on the station's inauguration day December 30, 1965, and the second unit was taken into service early in the new year 1966.
Around the time when the BBC Central Africa Relay Station was established, there was conjecture in radio circles that the initial mediumwave transmitter at Francistown was obtained from the temporary mediumwave station operated for the Voice of America on Sugarloaf in the Florida Keys. However, that conjecture turned out to be incorrect. The VOA Sugarloaf transmitter was a discard from mediumwave WBAL in Baltimore, Maryland; and it is known that the two mediumwave transmitters at the BBC Francistown were obtained from Continental in Dallas, Texas; Model 317C model numbers 12 & 13, both at 50 kW.
The initial frequency on mediumwave was 908 kHz, though when Rhodesia jammed the BBC station, other channels were in use at times, including 602, 925 and 926 kHz. On shortwave, the known channels in use were 4842, 4845, 5015, 7130 and 7295 kHz.
The temporary BBC Central Africa Relay Station at Francistown, Bechuanaland was on the air for exactly 2-1/4 years and it was finally closed and withdrawn from service on March 31, 1968. The two shortwave transmitters, 10 kW Marconi from England, were donated to Radio Botswana and re-installed at Gaberone.
The two mediumwave transmitters at Francistown, 50 kW Continental 317C, were removed; one was flown to England for use by the BBC, and the other was flown to Cyprus for installation at the BBC shortwave relay station at Zygi. The Cyprus unit was subsequently sold, somewhere around the year 1987; and the information about the unit in England is another interesting story that we plan to present on another occasion here in Wavescan, sometime in the early part of the New Year.
In addition, the BBC plans for subsequent radio coverage in these areas of Africa is another very interesting topic for another day in Wavescan.
We might also add, it is known that only a few QSLs were issued to verify the reception of the BBC Central Africa Relay Station, but not many.
Water Radio: Ancient & Modern
In this very interesting topic under the title, "Water Radio," we go back more than one hundred years ago to the wireless era under the Canadian experimenter, Reginald Fessenden. One of the experimental procedures that Fessenden utilized was a stream of water as the antenna for transmitting and receiving wireless transmissions. The German technical magazine, Electro-Technischen Zeitschrift, in its edition for November 6, 1905, makes reference to this novel procedure; and two subsequent issues published during the early part of the following year, give further information regarding this experimentation.
Fessenden attached a coil of copper tubing to a water pump, and the coil was also attached to the antenna terminal in the wireless equipment. It was discovered that the stream of water directed upwards served quite adequately as the antenna system, though it was observed that ocean saltwater performed better than fresh water.
Twenty years later, similar experiments were conducted in France by the French navy with the use of an upward stream of water as the antenna system. We quote a report in a British radio magazine, "Wireless World," dated February 28, 1925:
Similar experiments with the use of a jet of ocean water as an antenna for wireless transmissions from submarines were carried out during the year 1915.
We fast forward through 3/4 of a century to our current era, when a modern version of this same concept was successfully implemented. The Australian radio magazine, "Australian DX News," reported that similar experiments were conducted by the United States navy in the Pacific off the coast of San Diego recently. In this modern version, a jet stream of ocean water was directed upwards for the transmission and reception of radio signals.
The height of the water jet can be adjusted for the transmission and reception of radio signals in the regular shortwave, VHF & UHF bands; and in addition, multiple jets of water can be utilized for parallel transmissions and reception on different bands. It is stated that the usage of the water antenna, which takes up only a small space on the deck of a ship, is particularly useful on navy vessels, where there are as many as 80 different antennas already attached to the ship's super structures.
Back some 17 years earlier, the Canadian journal, "DX Ontario," reported another type of antenna system utilizing some form of water. In this Canadian version, a wire coat hanger is cut and inserted into a large plastic bottle containing regular anti-freeze, such as is used as the coolant in the radiator of a motor vehicle.
A small circular section of an aluminium pie plate is placed over the top of the plastic bottle, and the coaxial cable is attached to this novel antenna system. It is reported that this form of receiving antenna works effectively for specifically tuned high frequencies.
These five experiments that we have just listed utilized water as the antenna system for transmitting and receiving radio signals. We turn now to a couple of additional usages of water in association with radio reception.
Some time back, we reported that a radio receiver made in France can be used under water for the reception of FM transmissions. In connection with this topic, "Water Radio," we present that earlier information:
This brings us to the final item in "Water Radio," and it is a brief story about a new radio receiver that has been developed in England. This radio is powered by the flow of water. Several radio magazines have repeated this story, and it tells us that Trevor Baylis, who invented the famous Baylis wind up radio that was manufactured in South Africa several years ago, is responsible for this new Shower Radio.
This radio, according to BBC TV, is spliced into the piping for the bathroom shower. The flow of water in the shower system generates sufficient electricity to operate the radio receiver. Quite appropriately, this new radio receiver is registered as the H2O Radio.