http://www.nf6x.net/greenradio/6mcallfreq.html

6-Meter Calling Frequencies for Military Radios

The Military Collector's Group mailing list has selected the following calling frequencies for our green VHF radios:


51.0 MC General local FM use. Selected because all green 6M FM rigs can tune to this frequency, and crystal-controlled rigs are commonly tuned to this frequency when they leave the depot. Note that this freqency is at the edge of the radio control band, and is also near FM DX frequencies, so please limit use of this channel to low-powered rigs with lousy antennas.

51.6 MC FM DX work. Selected because all green 6M FM rigs can tune to this frequency, and it is compatible with known band plans. Also, rigs such as the PRC-68 can tune to both this frequency and 51.0 MC without reprogramming. This frequency is a common FM simplex frequency, so it should be used instead of 51.0 MC when possible, in order to avoid interfering with DX and RC users.

50.6 MC Alternate frequency, for AM, etc. Note that this frequency is at the edge of the "all-mode" band, and is near the digital/packet calling channel, so please use it with caution.