rjr@mgweed.UUCP (Bob Roehrig) (07/10/85)
Yes, it is legal to use "PL" tones or DTMF tones for signalling as long as that particular mode is authorized on the band you are using. Remember one thing that MOST commercial stations using tone activated receivers forget: DISABLE THE TONE CIRCUITRY BEFORE TRANSMITTING. That is, except on the 440 MHz ham band, it is illegal to transmit on a frequency before monitoring it. You can't do this unless you revert to carrier squelch! All "decent" repeaters that use subaudible tones have a 300 Hz (or so) hi-pass filter in the audio path so the tone is not repeated. I really hate to hear systems where people have their "PL" cranked up so high that it garbles the voice. Bob K9EUI
ron@brl-tgr.ARPA (Ron Natalie <ron>) (07/12/85)
> Remember one thing that MOST commercial stations using tone activated > receivers forget: DISABLE THE TONE CIRCUITRY BEFORE TRANSMITTING. > That is, except on the 440 MHz ham band, it is illegal to transmit on > a frequency before monitoring it. You can't do this unless you revert > to carrier squelch! > This is why the mike "hook" switch disables PL when you pick up the mike. -Ron