<<"This is why most rigs have seperate input for PL encode.">>
Actually, the main reason most newer rigs have a separate input for PL audio is because, generally, the audio signal modulates the VCO to produce the FM audio modulation. If the PL tone is also modulating the VCO, particularly with the lower PL frequencies, the synthesizer will see that as frequency error and try to correct the VCO in accordance with the PL modulation, producing what it known as "hunting". The PL tone, therefore, generally modulates the reference oscillator, and sometimes a combination of both VCO and reference oscillator, to eliminate this "hunting" phenomenon. I have seen schematics of a few ham radios where PL modulates only the VCO, but I have never had one on test equipment to see if it is free of the hunting. Perhaps I just missed the PL audio path to the reference oscillator. Tom --- In [email protected], Ron Wright <[EMAIL PROTECTED]> wrote: > > A good rig has a PL filter so you don't hear it, but know it comes thru on some rigs. Does sound annoying when it does. > > Also need to remove from the repeater receiver for it might beat with the tx generated PL due to it being slightly different freq/phase. Most rigs will not pass low freq PL thru their audio input. This is why most rigs have seperate input for PL encode. > > 73, ron, n9ee/r > > > > >From: JOHN MACKEY <[EMAIL PROTECTED]> > >Date: 2008/07/20 Sun PM 02:37:13 EDT > >To: [email protected] > >Subject: RE: [Repeater-Builder] Re: PL Problem > > > > >I set all my repeaters for 450 Hz to 550 hz and have never had a problem with > >listeners being able to decode. > > > >so something in the range that David suggests below should be fine. > > > >I know some people who think PL level should be set at 750 hz to 900 hz. In > >my opinion, that is way to high, and it is annoying to hear the PL tone which > >can be done at those levels. > > > >------ Original Message ------ > >Received: Sun, 20 Jul 2008 06:45:05 AM PDT > >From: "David Murman" <[EMAIL PROTECTED]> > >To: <[email protected]> > >Subject: RE: [Repeater-Builder] Re: PL Problem > > > >> Run all my repeaters with a tone of 600 hz. This is what GE recommended > >when > >> I was in the 2-way business. So far all three repeaters, two VHF and one > >> UHF have had no problem with any radio being able to decode the tone. > >> > >> > >> > >> > >> > >> > >> > >> David > >> > >> > >> > >> -----Original Message----- > >> From: [email protected] > >> [mailto:[EMAIL PROTECTED] On Behalf Of nj902 > >> Sent: Saturday, July 19, 2008 9:37 PM > >> To: [email protected] > >> Subject: [Repeater-Builder] Re: PL Problem > >> > >> > >> > >> Actually, what I think what I confirmed is that I passed reading > >> comprehension... > >> > >> > >> The "Standard" is 500 to 1000 Hz . Period. > >> > >> ................................................................. > >> > >> --- In Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com> > >> yahoogroups.com, "Eric Lemmon" <wb6fly@> > >> wrote: > >> > >> " My statement about the definition of "Standard CTCSS Modulation" is > >> correct, and thank you for confirming that. ..." > >> > >> > >> > >> > > > > > > > > > Ron Wright, N9EE > 727-376-6575 > MICRO COMPUTER CONCEPTS > Owner 146.64 repeater Tampa Bay, FL > No tone, all are welcome. >
