W2XMN

W2XMN was an experimental FM radio station located in Alpine, New Jersey. It was constructed beginning in 1936 by Edwin Howard Armstrong in order to promote his invention of wide-band FM broadcasting. W2XMN was the first FM station to begin regular operations, and was used to introduce FM broadcasting to the general public in the New York City area. The station, in addition to being a testing site for transmitter and receiver development, was used for propagation studies and as an over-the-air relay station for distributing network programming to other FM stations in the region.

W2XMN primarily operated on what became known as FM's "low band", mostly transmitting on 42.8 MHz until December 1946, and on 44.1 MHz thereafter. The station ceased operating in 1949, after the Federal Communications Commission (FCC) reassigned the "low band" frequencies (42-50 MHz) to other services. At this point most of W2XMN's functions were inherited by Armstrong's "high band" FM station, KE2XCC, located at the same Alpine site, which had been established in 1945 as W2XEA, and remained in operation until 1954.

Armstrong was already a well known radio inventor when he developed "wide-band frequency modulation" (FM) technology in the early 1930s, which he considered to be such a superior approach to radio transmissions that it would soon make existing "amplitude modulation" (AM) broadcasting stations obsolete. He initially sought the support of the largest U.S. radio company at the time, the Radio Corporation of America (RCA), and quietly made some developmental transmissions from that company's testing site at the Empire State Building in New York City. RCA eventually decided that it was not interested in FM, instead concentrating on television development, and asked Armstrong to remove his equipment.

Without RCA's support Armstrong faced a more difficult task in promoting FM, and began to recruit smaller electronics firms as allies. In addition, Armstrong was independently wealthy due to revenue from sales of his earlier patents, and could afford to spend large sums promoting FM himself. Because of the high transmitting frequencies in use, which tended to limit station ranges to "line-of-sight" distances, it was important to have signals broadcast from as high a point as possible. Armstrong arranged for the construction of a distinctive tower with three large cross-arms, located atop the Alpine, New Jersey Palisades overlooking the Hudson River a few kilometers north of New York City. On June 12, 1936, he was issued permission to operate an experimental station, with the call sign W2XMN, from the Alpine site. In 1938 this station was assigned to transmit on 42.8 MHz, which would be its primary frequency for the next ten years. (An additional temporary frequency assignment for 117.43 MHz was issued in 1941.)

A 1939 article in Fortune magazine dramatically described the station as "When W2XMN, on 42.8 megacycles (approximately seven meters), opened fire in 1938, it was the last gun to crush even the most obdurate opposition." In 1948 testimony, Armstrong recapped the events as:

Back in the dark ages, when we had static, people said: "There isn't anything you can do about it; that is one of the impossible problems nobody can solve." They said that for 20 years, but eventually it was solved. Today we have staticless broadcasting. But, after it was invented, people said: "Well, that is very nice, but it is too late; the broadcasting system is all built up. You cannot put it into use."

The reason they said that was this: Every other invention that had been made since broadcasting started was either an improvement on the transmitter or on the receiver of the existing system, so that the system did not have to be changed. But FM overcame static by producing a wave which was different from the static waves, so that it was possible to separate out these bedevilling natural electric waves which create static in our AM system from the AM wave. But that meant you had to have new transmitters and new receivers. So, we came to the "chicken and the egg" problem. People said: "You cannot establish FM broadcasting, because the public will not buy receivers until there are FM stations, and the broadcasters will not put up FM stations and spend the money until the public have receivers." And then there was an added variation on that, which was that the manufacturers would not build FM receivers. They did not like to be jarred out of an established rut, and change their techniques until there was a public demand for it.

So, for a time it was a merry ring-around-the-rosy, but it was solved in this way: I built an FM transmitter and started it going at a cost of $300,000. Then I financed one of our largest manufacturing companies to build FM sets. That is the way it started. After that we came to the practical situation of changing over from one system to the other... So, we answered it in this way: We said the way the change-over will be made will be this: "The broadcasters will set up FM stations which will parallel, carry the same program, as over their AM stations." The receivers which will be built will be adapted to receive both AM and FM at the option of the listener. Until such time as an FM station comes into his territory, he will use it as an AM receiver. Then after that, when the FM station comes in, he can get his program on FM by simply turning a switch and using the FM part of it, and get reception without static, and eventually the day will come, of course, when we will no longer have to build receivers capable of receiving both types of transmission, and then the AM transmitters will disappear.