In the 1930s investigations were begun into establishing radio stations broadcasting on "Very High Frequency" (VHF) assignments above 30 MHz. Reception of stations operating on these frequencies tended to be limited to line-of-sight distances, so placing the transmitting antenna at as high an altitude as possible provided maximum coverage. Stations operating on these higher frequencies were known informally as "Apex" stations, and initially employed "amplitude modulation" (AM) transmissions like those used in the standard AM broadcast band. Franklin M. Doolittle, the owner of AM station WDRC in Hartford, obtained permission to establish an experimental Apex station, W1XSL, with a transmitter site located on Meriden Mountain.