Back in the early days of wireless and radio, station callsigns were applied in several different ways; there was no clear, no regular pattern. Official internationally recognized callsigns were in use to identify a specific transmitter, or a specific transmitter frequency, or a particular programming service, or a particular transmitter usage, such as amateur, experimental, communication or broadcasting.
On one rather unusual occasion back then, a callsign that was licensed for a shortwave transmitter at one specific location was borrowed temporarily to identify another transmitter at another location one hundred miles distant. That event undoubtedly caused considerable confusion. (In 1931 for example, the English callsign G5SW was licensed to a Marconi 10 kW shortwave transmitter at Chelmsford, and it was borrowed by the BBC to identify the test transmissions over their two new 10 kW STC shortwave transmitters at Daventry.)
In more recent times, callsigns have been used simply to identify radio stations that may have one or more transmitters at one or more locations, like for example the fourteen transmitters at WRMI in Okeechobee Florida, or the five transmitters at KSDA on the island of Guam. But originally and historically, each callsign was intended to identify just one specific transmitter at a specific location.
The most appropriate usage of a radio callsign, we would suggest, is to identify a specific transmitter at a specific location. For example back in the middle of last century, the American callsign KWID identified a 100 kW shortwave General Electric transmitter that was installed in suburban San Francisco in California for the Voice of America; and the Australian callsign VLC identified an American made 50 kW RCA shortwave transmitter that was installed at Shepparton in Victoria for Radio Australia.
Back more than 100 years ago, the Marconi company at Chelmsford in England obtained a plethora of callsigns for their various longwave and shortwave transmitters and services. We go back to the beginning, and we start with the story of their very early radio factories in England.
It was in the year 1897, that the 23 year old Italian born Guglielmo Marconi established his first radio factory, a very small and primitive facility, at 28 Mark Lane in London, for the construction and experiment with very early wireless equipment. However, that facility in crowded London produced too much electrical interference, and it was far too small anyway, so he searched for a suitable country location, and he finally chose Chelmsford in the county of Essex, about 30 miles north east of London. Interestingly, that site was already the site for other companies that were manufacturing other electrical apparatuses and goods.
Now back in 1861, John Hall had constructed a two storied building on Hall Street in Chelmsford for use as a silk weaving mill, and when he went out of business, the building was taken over by the Wenly company for the storage of their finished furniture products. However that building became available, and so Marconi took it over for use as a wireless equipment factory in December 1898 under a 20 year lease agreement.
That building was the first radio factory in the world, and their first employees were 26 men, and 2 boys. In less than a year and with the use of his brand new wireless equipment, Marconi installed a wireless transmitting station across the roadway nearby.
During the year 1912, there were three major events that impacted the Marconi company in Chelmsford and the wireless equipment they manufactured. These three events in chronological order were:-
- The sinking of the luxury liner Titanic
- Construction of a new wireless factory building in Chelmsford
- Official visit from the many international delegates who were attending the International Radio Telegraphic Conference in London
In that tragic event on Sunday April 14, 1912, the luxury liner RMS Titanic struck an iceberg and in less than three hours it broke into two pieces and sank. The two Marconi wireless operators, 25 year old John Phillips and 22 year old Harold Bride, had sent out numerous Morse Code messages on their Marconi wireless equipment with the Marconi callsign MGY.
In response, the RMS Carpathia (callsign MPA) at full speed arrived at the scene two hours after the Titanic sank, and they were successful in rescuing 705 survivors from the icy cold Atlantic. Wide was the subsequent praise for the use of wireless equipment aboard the Titanic which ensured the rescue of so many survivors who would otherwise have been lost.
In Chelmsford, suitable land on the local cricket grounds at New Street near the railway station was chosen for the new wireless/radio factory. Construction work for that large new two storey factory building began on February 26 (1912) and in order to hasten the work 500 brick layers were employed.
The official opening of the new Marconi factory at Chelmsford on June 22 (1912) attracted delegates from the 35 countries who were attending the Third International Radio Telegraphic Conference in London. At the height of its success, this new wireless/radio factory employed a total of 6,000 people.
Early views of the Marconi factory in New Street, Chelmsford. Photos: Essex Record Office
During the subsequent almost one hundred years, Marconi Chelmsford manufactured untallied quantities of radio products, including high powered top quality international shortwave transmitters. Their now historic radio factory was ultimately closed in 2008, and it is these days in use as a luxury apartment complex.
This feature was written by Adrian Peterson and originally aired on Adventist World Radio’s “Wavescan” DX program of April 3, 2022.