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[aprssig] An amusing aside (Text Pagers)

Robert Bruninga bruninga at usna.edu
Fri Jan 29 18:18:00 UTC 2010


> ...would like to play with APRS TT..

Still we do not have someone to finish the coding.  There was a
version in work in France, then the author got busy with other
things.  Then there was the one that was working at Dayton last
year... Nothing heard from since...

So, still need someone that can tie together sound-card DTMF
decoding and a little APRS parsing to get a working program out
there...  I think it would revolutionize ham radio when everyone
with an HT or mobile rig can be seen on APRS and send/receive
text messages.

Bob
Wb4apr

   I think it would be 
> great to  get a small system going in the  Peoria IL area.. 
> IS the equipment very expensive ?
> 
> 
> On Fri, Jan 29, 2010 at 9:03 AM, Robert Bruninga 
> <bruninga at usna.edu> wrote:
> 
> 
> 	> So we have 2 problems....
> 	> 1)algorithmically deriving a CAP code from a callsign.
> 	
> 	The plan would be to make the 21 bit POCSAG code equal
to the 4
> 	character callsign suffix.  There is room for 3 alpha
and one
> 	alphanumeric.  There may be some extremely rare
conflicts.  But
> 	an instantaneous check of global APRS would tell us of
any
> 	conflicts and those two people could manage it.
Besides,
> 	messages will only appear in THEIR local RF POCSAG area
and the
> 	chance of both of them living in the same RF area is
extremely
> 	rare.
> 	
> 	> 2)Notifying the POCSAG message server that my pager is
> 	> around.
> 	
> 	Doesn't matter.  APRS already knows where you are.  And
ALL text
> 	messages that are addressed to your callsign are
converted to
> 	your POCSAG code and transmitted out on your local
POCSAG
> 	channel.
> 	
> 	Ah, but what about those people who are not otherwise on
> 	APRS?... How does APRS know where they are?  ANSWER.
Their
> 	callsign in pre-programmed into their HT or Mobile DTMF
momory.
> 	All the user has to do is ONCE send out his DTMF memory
> 	callsign, and APRS now knows where he is (until he moves
to
> 	another local RF area and sends out his DTMF call
there).
> 	
> 	That was one of the main motivations of the POCSAG APRS
pagers,
> 	to give text-back capabilities to anyone with a radio.
He can
> 	use his DTMF to send messages.  That is what we have
called
> 	APRStt. (Touch Tone).  www.aprs.org/aprstt.html
> 	
> 	Anyway, I really think this woiuld be a fun ham radio
project
> 	and CHEAP which eveyone enjoys..
> 	
> 	Bob, Wb4APR
> 	
> 	
> 	
> 	
> 	
> 	
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> 
> 
> 




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