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"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, August 1, 2010
Beam Wireless Stations in England
You will remember from the information here in Wavescan last week, that way back one hundred years ago, the original concept for worldwide communication was with the usage of super high power on very low frequencies. Then, because of the subsequent experimentation with the broadcast of radio signals on shortwave frequencies, it was realized that a more reliable form of international communication could be achieved with the usage of lower power on shortwave frequencies, at a considerably lower cost.
Thus it was, that the Imperial Wireless Scheme, with a chain of super high powered longwave stations stretching from England to Australia via the Middle East, Africa and Asia was cancelled in the early 1920s, and in its place the Marconi company implemented a series of Beam Wireless Stations at the same locations. These stations were to be installed with the usage of the new valve or tube equipment, and the stations were to be located no more than 2,000 miles apart.
In the early and mid 1920s, several new Beam Wireless Stations were erected in England with the intent that each would be a key station for a communication service with a specific part of the world. Several of these stations were in use on occasions with the relay of radio programming for broadcast elsewhere, and for the transmission of news and commentaries from one part of the world to another.
The first of these new Beam Wireless Stations in England was installed at Leafield in Oxfordshire. Interest in this location began in the year 1912 when Marconi conducted experimental wireless transmissions in Morse Code. The partially built location was protected by the Home Guard during World War I, and a massive high powered longwave spark wireless station was installed in 1922 under the callsign GBL. Soon afterwards, electronic transmitters were installed, and these were on the air on shortwave under the callsigns GBM and GBO.
During World War II, Leafield was an important communication station, and in the 1960s it was upgraded and modernized, mainly for maritime communication, and it became one of the major stations known as Portishead Radio. The receiver station for Leafield was located at Devizes in Wiltshire. This Leafield station was finally closed in 1986 and the property was sold to a local college. Soon afterwards it was sold again, and it is now in use as a closed circuit for motor car racing.
Another Beam Wireless Station was installed at Bodmin in Cornwall and this station served as the England terminal for communication with Canada and South Africa under the callsigns GBJ and GBK. This station was opened for service at the end of a week long series of test transmissions in October 1927. The receiver station for Bodmin was located at Bridgewater.
During the late 1930s, the equipment at this station was dismantled, removed, transferred and re-erected at Dorchester, as a safety procedure due to political developments on continental Europe.
Another important Beam Wireless Station was erected at Grimsby in Cornwall in 1927. This was a very large station with a series of curtain antennas stretching for one mile. In actual reality, this was a double station with twin 20 kW transmitters. The Grimsby side communicated with Australia, and the Tetney side communicated with India.
This station was established and operated by the Marconi Company, and it was later taken over by Cable & Wireless. The callsigns in use at Grimsby-Tetney were GBH and GBI, and the receiver station was located at Winthorpe.
Another Beam Wireless Station during this era was constructed by the Marconi Company at Dorchester in the south of England. This was a very large station with two transmitter buildings and a bevy of curtain antenna systems on 460 acres of land.
The first transmitter hall at Dorchester initially contained four Marconi transmitters at 10 kW each, and the second transmitter hall contained eight transmitters at a similar power rating. Subsequently, at least a dozen higher powered transmitters rated around 30 kW were installed. The receiver station for the Dorchester transmitting station was located at nearby Somerton.
The Dorchester station was constructed specifically as the England terminal for communication circuits with Japan and Egypt, though subsequently, Asia, South Africa, North America and Australia were added. The main callsign for the American circuit at the Dorchester station was GLH, and for the South American circuit, GLW. This station was finally closed in April 1978.
The original concept for the terminals of the Beam Wireless Stations in England called for six separate stations, though this number was soon afterwards expanded to nine stations, and even more. Not mentioned yet is the huge and well known Beam Wireless Station that was located at Rugby, and on many occasions, Rugby Radio carried broadcasts on shortwave from the BBC in London. That will be our story on another occasion.
Radio Panorama - 2: Distant Communication in Ancient Times, Visual
As part of the first program in Wavescan here at the beginning of each month, we are now presenting a historic and progressive rundown of old communication history that will culminate ultimately in the development of wireless and radio; and on this occasion, we present the story of long distance communication in ancient historic times; that is visual communication.
Over the centuries anciently, one of the greatest problems encountered by the national governments and by conquering armies was the matter of effective long distance communication. How could they send information over long distances, and how could they receive information from a long distance, quickly and effectively?
Many ingenious methods and procedures were developed over a period of time, though a lengthy duration was always involved in the total time from the sending of the message at the point of origin to its reception at a distant point. We take a glimpse at some of these ingenious procedures, all involving the visual transmission of the message.
For example, back around 1200 BC, the Greeks used a series of beacon fires to warn about the coming of an invading army. The pre-arranged signal at the lighting of the first fire was the sign that the invaders were coming, and so each fire in this series of hilltop beacon fires carried the message quickly to its intended destination.
Somewhere around the year 540 BC, the notable Persian conqueror, Cyrus the Great, introduced the first known version of what we would call the Pony Express. A royal successor by the name of Darius, improved the Pony Express system in the ancient Persian Empire and he stationed fresh horses and riders at 25 mile intervals. These Persian riders with their important messages were able to cover up to 200 miles a day.
Another innovative aspect of the Persian Pony Express was the fact that the messages carried by the riders were written in the Aramaic language which was the official language of the empire. However, these messages were written with the use of the Phoenician alphabet, thus making the reading of the document much easier, and therefore its translation into local languages much quicker.
Around about the same time, the Greeks invented another form of visual communication, though quite cumbersome. A brick wall was built with indentations along the top row, and each indentation represented a letter in the Greek alphabet. The sender would carry a lighted torch and he would flash it at the appropriate opening, thus spelling out the desired message. This procedure required a brick wall at every interval for the transmission of the message.
It is said that the first marathon runner was a man by the name of Phidippides. In the year 490 BC, he ran a distance of 150 miles in two days with a message warning the city of Athens that the Persians were about to invade their city. The city was saved, but the runner died from exhaustion.
On another occasion, ships in the Athenian navy exchanged messages by shining the sunlight from polished brass shields. These messages simply conveyed a yes or no intent, according to the pre-arranged usage of these procedures.
Around about the same time, there was an interesting usage of beacon fires, not to send a message, but to confuse the situation when others were sending a message by beacon fire. At what is called the siege of Plataea in Greece, the invading Thebans were using a series of beacon fires to convey their messages. However, by pre-arrangement, the Plataeans themselves lit a series of beacon fires, and this confused the invaders as to what was really happening.
Around the year 500 AD, the Chinese initiated a new procedure for conveying messages out of a besieged city. They lit small lanterns and attached them to a kite. This procedure, it is said, began the Chinese customs associated with the usage of red lanterns.
Around about a thousand years ago, the use of homing pigeons to carry a small written message was introduced by citizens in the city of Baghdad, Iraq. This procedure is, of course, a one way method of communication.
As we progress down through the years, we come to the era of European exploration and settlement. The new immigrants to North America discovered that the American Indians could sometimes send a message as a smoke signal. Certain puffs of smoke from a bonfire had a meaning. It is understood that the American Indians controlled the intervals between the puffs of smoke by using a woven blanket or a stone bowl.
We come now to the year 1776, and that was the year in which the American navy first introduced the sending of messages from ships at sea with the use of signaling flags. Over the years, the procedures have been modified and improved, yet this method is still used at times.
And so we have seen how various methods and procedures have been invented for the transmission of messages over a lengthy distance. All of these procedures have been with the usage of some form of visual method. Next month, we plan to present you with some further information on long distance signaling, this time not by sight, but instead by sound.