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.