[aprssig] APRStt lives! (PL and DCS)
Robert Bruninga
bruninga at usna.edu
Mon May 17 19:15:56 EDT 2010
Byonics also had a working hardware APRStt demonstration plus
more good ideas...
Byon and Allen revitalized a long forgotten APRStt idea of using
PL and DCS squelch codes as another way of associating a
callsign. There are something like 40 PL tones and over 100 DCS
codes allowing at least 140 different PL/DCS callsign
associations in any given local area. For local club events,
this means that on the voice channels and nets, a simple PL/DCS
detector can make instant callsign-associations for APRS by
simply monitoring the voice transmissions. When someone is
talking, we know who it is electronically and can integrate that
into APRS!
By combining this instant callsign recognition, with 2 or 4
digit DTMF key presses, all Voice useers at an event can enter
APRS or other data very quickly and conveniently. For example,
a 3 digit number can localize anhyone to within 180 yards
anywhere along a 26 mile marathon. Again, using ANY HT with a
DTMF keypad.
Of course this works with any DTMF radio and with APRStt. But
this new idea, eliminates the requirement to send the callsign
by DTMF that is noisy and takes longer.
So watch out. This PL and DCS identification for special events
has GREAT potential if we can get a simple circuit to decode the
tones and codes, or someone to write a PL tone and DCS decoder
for a sound card. Then this can just be a PC application at the
special event!
Think outside the box. How can you use this capability for easy
reporting of simple data by ANYOONE with an HT at your next
event.
Bob, WB4APR
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