What is needed for APRS?

[Omega]

What is needed for APRS?

Of course, a GPS unit, a radio and an TNC. But how do you link them,
configure them? What software is needed. And are there units that are stand
alone? I believe that MFJ has such units, at least a radio/TNC combination.

What frequencies are used?

And where does one go for basic information?

From what I have read, APRS is a special aspect of Packet. I am
familiar with Packet.

Thanks...

[tom]

It might be harder than you think --- I installed, configured, and got up
and running with AGWPE Packet Engine
(and it's client AGWTerm), Multipsk, POC32, Digipan, MixW2 and a host of
lesser applications purported to be capable of decoding digital signals of
one format or another. Then I systematically scanned the spectrum from
530khz to 1ghz (minus a few chunks) and found a total of 20 - 30 clear,
non-voice, data signals of one type or another which I fed into my
soundcard's 'line in' receptacle, with these applications running. I know
the input was going where it was supposed to because the waterfall display
showed the various signals as they beeped, warbled, and chirped. Sometimes,
when Mixw2 was in certain modes, garbage would appear, but after all of that
time and effort with all of those applications, not even ONE signal got
decoded. I listened to samples of digital signals on a website and I was
certain that I had found pager signals, but POC32 didn't think they were
pages. I tuned into the national APRS uplink channel and I could hear what
sounded like mobile APRS stations uploading their little frames of data, but
WinAPRS wouldn't decode them. What's my point in all of this? If you're
thinking, "Boy, that digital mode idea seems interesting, why, maybe I'll
just down load some of those applications sometime and
decode some digital signals." Don't be so sure. Yes, all of those
applications CLAIM to be able to decode the right kind of digital signal,
but I tried every data signal, on almost the whole radio spectrum, and I
tried each signal with each mode-setting on each of those applications, and
it didn't work for me, not even once --- maybe it only works for certain
people.