In May 1940, the Federal Communications Commission (FCC) authorized an FM band effective January 1, 1941, operating on 40 channels spanning 42–50 MHz.
At this time Edwin Howard Armstrong, the inventor of "wide-band" FM, was already operating experimental station W2XMN on 42.8 MHz, transmitting from a tower he had constructed a few miles north of New York City in Alpine, New Jersey.
Under the new provisions he was granted an additional authorization for a commercial station broadcasting on 43.1 MHz from the Alpine site, which was issued the call sign W31NY.
Operating from the Alpine tower, WFMN's HAAT was calculated to be 795 feet (242 meters), so to maintain the same coverage it was restricted to an ERP power of 6 kW.
[14] In 1945, the FCC implemented a major reallocation, known as the "CBS plan", designed to standardize the coverage of New York City FM stations[15] This resulted in WFMN being reassigned to 98.9 MHz.
[23] The last reported STA grant lasted until February 1, 1953, which was an authorization "to suspend regular broadcasting service of WFMN and to operate Class I Experimental Station KE2XCC using its regularly licensed equipment, power and emission on the additional frequency of 93.1 mc for providing FM program service..."[24] There appear to be no further references to WFMN after this, and all other broadcasting activities from the Alpine site ceased following Armstrong's death in early 1954.