[Xastir] System cost options

[Tom Russo]

On Wed, Jun 27, 2007 at 08:50:20AM -0700, we recorded a bogon-computron collision of the <archer at eskimo.com> flavor, containing:
> On Tue, 26 Jun 2007, Tom Russo wrote:
> 
> > That depends on the local APRS infrastructure and how it's loaded.  That 300mW
> > might be enough to hit a digipeater if your terrain is right and your
> > infrastructure is built up enough.  Once it gets digipeated, the power of the
> > original tracker is less important.  There is no infrastructure you can
> > leverage with a Rino, and it's strictly line-of-sight between tracker and
> > receiver.
> 
> Even if a few tests when the frequency is not extremely busy look
> like the 300mW can get into digipeaters, if you are in hilly terrain
> or if pretty much _anyone_ else transmits when you do, you're not
> going to get into the digipeater.  For the most part, to have an
> equal chance to get into the digi, most people need to run roughly
> the same power levels.  Mobiles that are running 50W and good
> antennas will easily capture the digipeater over you, and you won't
> get heard.
> 
> I still stick by my 5-8W recommendation for portables.  FWIW I run a
> 1/4 wave whip on the roof of my Cherokee fed by a TM-261A mobile
> radio set to medium power and have excellent results.  I don't tend
> to bump it up to 50W anymore.
> 
> The rest of Tom's response was spot-on.  Just had to get my slight
> disagreement stated above.

We don't disagree that much.

I am very distrustful of these ultra-low-power, deaf trackers.

But there are many of them getting made, so *somebody* must be finding them
useful.  To be useful, the APRS infrastructure must be very good, the terrain
must be wide open, and the loading of the infrastructure must be low.  I
hinted at that with my first paragraph.

I would never use a 300mW tracker out here, where 5W is barely enough to 
assure adequate coverage in canyons.  Milage can vary, though, and I was
allowing for that.

I recommend using beefy trackers for SAR, too.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 http://kevan.org/brain.cgi?DDTNM
"And, isn't sanity really just a one-trick pony anyway? I mean all you get is
 one trick, rational thinking, but when you're good and crazy, oooh, oooh,
 oooh, the sky is the limit!"  --- The Tick