Paul, The same happens with DTMF. If one has too much distortion the low group harmonics get into the high group and confuse the decoder. DTMF decoder ICs do the same period averaging.
On the uhhhh thing use to be more of a problem with SSB and VOX. Some of us to prevent clipping of the first word during key up would get into the habit of saying uhhh before we started talking. Was more of a mental thing and not necessary, hi. 73, ron, n9ee/r >From: Paul Plack <[EMAIL PROTECTED]> >Date: 2008/07/20 Sun PM 04:48:40 EDT >To: [email protected] >Subject: Re: Re: RE: [Repeater-Builder] Re: PL Problem > >Guys, this is nothing more than really low-frequency DTMF. It should work >fine if the levels are low enough that they're not clipped or otherwise >distorted. In a non-linear stage, they'll cause audio intermodulation >distortion. If the combined voice + CTCSS level hits the limits of a clipper >for a long enough duration, (like the guys who feel the need to key their mics >before thinking of what they'll say, and fill with "uhhhhhhhh..<wbr>.") you >could drop the receiver if the audio distortion confuses the CTCSS decoder. >But that could happen with a single tione, too. 73,Paul, AE4KR ----- >Original Message ----- From: Ron Wright To: >[email protected] Sent: Sunday, July 20, 2008 1:10 PM >Subject: Re: Re: RE: [Repeater-Builder] Re: PL Problem > >John, > >I've wondered about multi-PL tones at one time. > >I am sure with the older reeds not a problem, but newer IC type usually take >in the PL, strip off the higher freq audio leaving only the PL and then feed >to a pin that I am sure is counting the period or doing some period >averaging. The Comm Spec TS64 has to be this way for they use a 6800 ventage >CPU for their decoder. > >If 2 PLs were present this would have a wierd wave form and bet might not >decode. I've never tried it, but would be interesting to try. > >I have used multi-PLs on a single rcvr for control and other purposes, but >never at the same time. > >73, ron, n9ee/r > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
