Following World War One, the Marconi Company in Great Britain began producing vacuum-tube continuous-wave transmitters. To test the new equipment, the company built experimental stations, including one at Chelmsford, near London. The history of this station is reviewed in the first volume of Asa Briggs' "History of Broadcasting in the United Kingdom". According to Briggs, the Chelmsford station was built in late 1919, and by early 1920 was operating with a 15,000 watt transmitter. From February 23rd to March 6th two daily half-hour news and entertainment broadcasts were made, mainly by Marconi staff. At this point a major London newspaper, the Daily Mail, became interested in the activities, and made the arrangements to have Dame Nellie Melba make this historic broadcast from the station.
Hugo Gernsback, editor of Radio News, was a promoter of simplified phonetic spelling -- hence the unusual spelling found for some of the words in this article.
Radio News, September, 1920, page 133:
ON June 15th of this year the Daily Mail of London inaugurated the first "world" concert, in conjunction with the famous opera star, Madame Nellie Melba, transmitting her voice over vast distances; the music in some instances was heard over a thousand miles away from the sending station. Madame Melba was performing at Chelmsford, near London, singing into the microphone of a standard radio telephone apparatus.
There was nothing radically new employed in sending out her voice, the apparatus used being well known and similar to what has been described time and again in this publication. The voice, on the other hand, was heard over a great expanse of space wherever there was a radio receiving station within range which had suitable apparatus for the interception of the concert, which, by the way, started at seven o'clock in the evening, London time. The results left nothing to be desired. As a matter of fact, the several voices came thru excellently.
First a deep voice slowly announced the program, then came the first strains from the piano, and finally the clear voice of the noted singer. Several selections were rendered by Madame Melba, and the concert terminated with the British national anthem, "God Save the King."
At Paris, the Societé Française Radio Electrique, on the other hand, took elaborate precautions to receive the music in a totally unlike manner than has ever been accomplisht before. This company, with its headquarters at Levallois, near Paris, erected a special booth, where by means of elaborate tuning apparatus, as well as vacuum tubes in great profusion, Madame Melba's voice was received and demonstrated to a large audience by means of a big aluminum horn. The experiments, however, did not by any means end there. The climax came -- and here is where the novelty comes in -- when the Societé used a special apparatus comprised of nine vacuum tubes with which to receive the music. It is interesting to note that, altho no antenna or even a loop antenna was used, the music not alone was received over the distance of several hundred miles, but was actually registered upon a master phonograph disc! From this master, actual phonograph discs were afterwards made, and all of them were quite clear. Here, indeed, is a worth-while novelty! While, of course, there is nothing new about "canning" radio telegraph messages, the idea of catching the voice of a great opera singer by radio on a phonographic disc seems rather novel and presents great possibilities.
The point we want to make here is that, altho America is supposed to be a country bordering close to the radio milennium, and, altho there are practically no restrictions and the law is all with the amateurs, progress, as far as radio telephony is concerned, is negligible.
In Europe, where the restrictions are very severe, and where special authorization for such an experiment as the above-described one must be had, it seems the art is thriving even more vigorously than here, where there are no such restrictions. In other words, real enterprise, as far as radio telephony and radio concerts, etc., is concerned, is rather frail and spasmodic here. Of course, there are many radiophone sets in the United States now, and these are growing all the time, but there are very few big "stunts" that come to ones notice, as, for instance, the one of Madame Melba described above.
There is nothing that popularizes radio more than a concert by a famous singer, and it is to be hoped that our amateurs, as well as professionals, shall band together and try for some original ideas. We wish to suggest here only a few:
Why cannot someone go after the Presidential candidates and invite them to make a speech via radio thru a powerful telephone apparatus in the near future? With proper advertising and with the proper enterprise behind such a scheme, it certainly should not cost a great deal to do. The people of the United States, thru the amateurs, would get a chance to listen to our candidates in a very novel manner. Another idea, which, of course, is not new, would be to transmit band concerts from famous bandmasters broadcast. Such concerts could be sent from some of the big centers, such as New York, Chicago, or perhaps Atlantic City, or some other points where the bands are staying at the time.
Of course, there are countless schemes and ideas of a similar nature, all of which make it possible to popularize radio, and that is what we are after. Now, why don't we get together and do it?
Radio News, a monthly magazine, was in a good position to take its editor's words to heart, and at this time could have easily started up broadcasting activities. However, despite this stirring front-page "call to arms", it wasn't until mid-1925 that the magazine set up its own broadcasting station, WRNY in New York City -- by this time many hundreds of other broadcasting stations had already taken to the airwaves.
At the time of the Nellie Melba broadcast, even a 500-watt vacuum-tube transmitter was considered quite powerful -- Chelmsford's experimental 15,000 watt transmitter would have put out a tremendous signal. Moreover, it operated on a longwave frequency of 120 kilohertz (2500 meters), which meant it had a huge groundwave coverage. This led to complaints about interference, especially by the military, and before the end of 1920 the Post Office, which regulated radio in the United Kingdom, put a stop to the entertainment broadcasts. The ban remained in effect until early 1922.
The combination of vacuum-tube transmitters, opera, and the Nellie Melba concert would have an international impact. For example, see Early History of Radio Broadcasting in Argentina by Carlos A. Altgelt.