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RE: TDMA - Reading the mail



> Kinda like APRS...
> In APRS PTT mode, your LAT/LONG/CSE/SPD/ICON/COmment and 
> STATUS are all
> encoded into a 0.3 sec burst when you release the PTT.  The 
> D7(G) and D700
> can do it in under 0.1 sec at 9600 baud and hardly noticible at all.

I was thinking of this mode when I said that. :-)  It's a great idea in
theory, but it is tacked onto the analog system.  With digital, this could
be integral to the system, and totally transparent to the end user.

> I know this is not related to the general topic of a new 
> digital mode, but
> the fact that we have had this mode now for 6 years, and only 
> a very small
> handful of folks have ever tried it shows you how hard it is 
> to get people
> to try something new on the satellites...  And all they had 
> to do was hook
> up their existing PACKET TNC to play..

Well, some of us don't have a TNC to play with.  :-)

> No real point here, other than some pessimism at trying to experiment
> with somthing new on Ham Radio... <grin>

Guess it depends on what it is.  :-)  I think APRS is a fantastic system,
and I've had a play with it at home.  I haven't had a play with a tracker
yet, because:

1.  I don't have a GPS, and am unlikely to get one in the near future
(though I have put my name down for a GPS engine, the next time someone
manages to bring in surplus units).

2.  I don't run mobile very often (being a public transport commuter), and
when I do, the radio setup is very temporary (HT, hands free, powered from
the cig lighter).

3.  Portable options are either expensive (Kenwood D7 HT) or ungainly.

4.  The APRS network here is independent of the voice frequencies, so
running APRS would mean dedicating a rig to that purpose (hmm, 2 rigs and a
GPS might clash with the tie! LOL).  Would be nice if PTT mode encoding was
recognised by at least one station on the repeater and then forwarded to the
general APRS network.  If I could, without undue cost or intrusion on normal
operations, I would be beaconing APRS at every opportunity.  Unfortunately,
this isn't yet a reality for me. :-(

Not bagging APRS (it's an excellent system, and I intend showing it to a
storm chaser friend of mine among others - he was impressed with the .GIF
sample maps I sent him), but more highlighting issues of APRS non
integration with other ham operations.  APRS could serve us better if there
was more integration, and digital systems are a natural for such
integration.
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