Two very early FM airchecks added:
W2XOR sign on and transmitter dedication, Aug. 1, 1940. This was the experimental FM for WOR.
W71NY dedication of new 10 KW transmitter, Nov. 30, 1941. This was WOR's FM station with a regular FM broadcast license. The callsign tells you it was on 47.1 MHz (in the old FM band) an that it was licensed to New York City. This alphanumerical call letter system was unpopular, and FM stations switched to the modern call letter system in 1943. Thus W59NY on 45.9 MHz became WQXR-FM, W67B on 46.7 MHz became WBZ-FM, etc.
http://jeff560.tripod.com/sounds.html
W2XOR sign on and transmitter dedication, Aug. 1, 1940. This was the experimental FM for WOR.
W71NY dedication of new 10 KW transmitter, Nov. 30, 1941. This was WOR's FM station with a regular FM broadcast license. The callsign tells you it was on 47.1 MHz (in the old FM band) an that it was licensed to New York City. This alphanumerical call letter system was unpopular, and FM stations switched to the modern call letter system in 1943. Thus W59NY on 45.9 MHz became WQXR-FM, W67B on 46.7 MHz became WBZ-FM, etc.
http://jeff560.tripod.com/sounds.html