[aprssig] APRS touch-tone and PL and repeaters?

Robert Bruninga bruninga at usna.edu
Wed May 6 10:06:27 EDT 2009

>> Every DTMF APRS user pre-sets his callsign 
>> into a DTMF memory so that he can send it 
>> wherever and whenever.  
> I thought, perhaps you were proposing to also 
> require a single special (a.k.a. "standard") 
> PL to inhibit the DTMF from escaping on the 
> repeater output, or something-or-other like that.  

Hummh... Now that is an idea...
Do the controllers on repeaters with PL (CTCSS) on their input
still hear everything on the channel?  What about control codes
form DTMF?  My very limited experience would suggest that these
repeater controllers are operating the repeater input with OPEN
SQUELCH in order to have a fast reaction, and then only use the
presence of PL to decide when to bring up the output and
patch-over the audio.

So having a unique PL on the APRStt DTMF string would pevent the
repeater from coming up, but would all those DTMF tones still
potentially scrmable the repeater controller's DTMF decoder?

Good question.  If repeater controllers, on the other hand, are
immune to DTMF codes that do not match their PL, then maybe you
have just opened up a potential way that could make it easy to
add APRStt to some repeaters.


> > Having random people sending random digits on random 
> repeaters scares the
> > begesus out of repeater owners.  So we have abandoned that
> > and are going with setting it up on a simplex frequency.
>    Roger on the begesus O.M.   So it's the APRStt idea itself 
> that raised a few neck-hairs.  Yea, I can see that concern.  
> Bleep, bleep, bleep all the time...
> -- 73, Steve, K9DCI  Wouldn't that be Bejesus, anyway?  
> (capitalise a proper name. hi hi)

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