[aprssig] Quick and dirty weather

Scott Miller scott at opentrac.org
Fri Apr 15 12:28:47 EDT 2005

I've been running a 1-wire station off an OpenTracker off and on for a while
at my house, testing out solar charging setups and such.  Decided I wanted
to make it a permanent installation, but didn't want to devote another
antenna, radio, and power supply to the effort.

What I wound up doing was plugging a DB9 Y cable between the KPC-3 on my
IGate and the radio cable.  Jumpered the KPC-3 for external power, clipped
the PTT diodes on the tracker so it'd play nice, and plugged it in to the
other side of the Y.  Now they both use the same radio, and the KPC-3 powers
the OpenTracker without any extra wiring.  A few obvious deficiencies come
to mind:

1. No collision avoidance between the two
2. OpenTracker can't run open squelch
3. IGate can't hear the tracker

Number 1 isn't a big deal, since they both transmit infrequently.  Number 2
is annoying, but my IGate hears 99% of its traffic from a couple of WIDEs
and they've got long enough TXDs and strong enough signals that running open
squelch doesn't really help anything.  And as for number 3, it's running a
single-hop path, so the IGate hears the packet as it comes back from the

It's quick and dirty, but it's simple and it works.  Just a Y cable,
OpenTracker, 1-wire cable, and weather sensor unit.  I don't think this is
what Kantronics intended when they put in the external power jumper, but it


Scott, N1VG

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