Setting tones might be the CTCSS (Continuous Tone Controlled Squelch System)
a sub audible tone in the range of 67 to 254 Hz.

Some FM repeaters require the CTCSS tone in order to access the repeater.

Sometimes called PL (Private Line - a Motorola TradeMark).

URL:
http://www.pacres.com/ctcss.htm

--
KeyBoard In The Wilderness



wrote in message
...
Maybe I shouldn't even ask what is it about setting tones to pick up and
talk to other Hams? Wouldn't want to interrupt their little teaparty.
cuhulin