[aprssig] A TNC2 (clone) question

[Tom Hayward]

On Mon, Nov 14, 2011 at 07:24,  <kc8sfq at mei.net> wrote:
> My questions:
> 1: Will the MFJ1274 support the new n-N paradigm? or will it need to be
> addressed by it's specific callsign-SSID? (I know it's been upgraded to at
> least 1.2.9 firmware)

No; yes.

> 2: will the MFJ even function as an APRS DIGI? (my understanding is that
> there's nothing special about an APRS packet as far as a DIGI is concerned)

It will digi its own callsign and alias. The downside to this is if
you want to do it by callsign, you need to have all of your SAR
personel reconfigure their trackers when the portable digi is turned
on, and again reconfigure all of their trackers when the portable digi
is taken down, runs out of batteries, etc. Or, you could set the alias
to WIDE1-1, but you don't have callsign substitution; this is poor
form on APRS when there are so many affordable options available that
will do proper digipeating with callsign substitution.

If I were to build a SAR digipeater, it would be with a
Tracker2:http://www.argentdata.com/products/tracker2.html

Have your SAR personnel set their trackers to WIDE1-1,WIDE2-1,SAR7-7.
Configure the Tracker2 to preempt on SARn-N. This way, the trackers
still get into the normal network if available. When you have a SAR
network in place, it will digipeat your SAR trackers but not the rest
of the stations on 144.39.

Tom KD7LXL