The Philip B. Petersen Collection Broadcast January 21, 1989

Major Edwin Howard Armstrong

     One of the modes of operation radio amateurs use today is FM.  FM means frequency modulation.  It's used primarily in mobile communications along with the police, fire, taxicabs and the like.  The inventor of frequency modulation was Major Edwin Howard Armstrong.  He also had other inventions to his credit.  Prior to World War I, Armstrong invented the regenerative detector, which greatly improved the sensitivity of the early day radios.  A little later, the super-regenerative detector was developed which greatly improved the sensitivity and amplitude.  During World War I, when he was a major in the U.S. Army Signal Corps, he invented the superheterodyne circuit.  Well, the Armstrong superheterodyne circuit made such a great improvement that just about every radio receiver made used the Armstrong superheterodyne circuit.
     The AM broadcasting industry started in October 1920 and they were using the Armstrong superheterodyne circuits by the tens of millions.  In the 1930s, AM broadcasting was still booming with AM radio but it had some drawbacks.  The amplitude modulation was very susceptible to electrical noises and static and lacked the high fidelity quality.
     Armstrong got thinking about this and developed what he called a frequency modulation system.  This had the inherent characteristics of suppressing noise static and it also, at the same time, greatly improved the fidelity of the communication.  As soon as he announced this type of FM system, he was met with strong opposition from the vested interest in amplitude modulation broadcasting who did not want to see any new type of method of broadcasting.  This went on for years in litigation but finally, in 1939, the FCC did issue a license for Armstrong to operate a frequency modulation broadcasting station in Alpine, New Jersey at approximately 50 megacycles on the dial.
     Soon a few more stations were also operating on FM around the country, but the manufacturers of AM radios were reluctant to manufacture FM radios.  Those few persons who were able to obtain a FM radio were immediately pleased with the reception.  Two years later, World War II broke out and the manufacture of all broadcasting radios ceased.  It was not until five years later that America started to make more broadcast radios.  In the meantime, the Armstrong FM system was used in our U.S. Army radio sets in World War II with great success.
     After the war, the FCC relocated the FM broadcasting band from 50 megacycles to its present location at 88 to 108 megacycles.  Today we can now enjoy the high fidelity quality of FM broadcasting.  All radio amateurs enjoy it too in our FM modes of radio communication.  The man who was responsible and deserves all the credit for bringing it to us is Major Edwin Howard Armstrong.  Don't forget him.  He is one of the great inventors of radio communications.

January 21, 1989

** Broadcasts recordings preserved and presented here by Mr. Robert Buss and Mr. Bernie Ricciardi, Phil's friends and fellow Marconi Chapter 138 QCWA members **

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