Desires of an APRS mobile Installation

March 5, 2008 12:05 AM

If there's one thing I want to do before storm season hits, it's get APRS running in my car for when I'm out spotting. Some of you may have remembered my previous attempt at doing such a thing. While it worked well, it found itself in the hands of stupid theives.

My first try at doing APRS mobile involved a TNC-X with an XTrack board and a Yaesu VX-150. I hacked a Plano tackle box and put both the TNC and radio inside the box. I wired in a BNC connector to the outside of the box, as well as connections for power and the GPS, which was a Duelo unit. It wasn't stolen like the rest of my equipment, but as I found out later, had suffered some sort of electrical incident as a result of the ordeal.

This worked quite well. Especially so after I had, with the help of Greg, W0AAI, built a box that would turn the APRS tracker box on and off with my ignition. Beaconing would occur every 2 or 3 minutes.

But since that second day of 2007, I've become a little more careful. My radios, once replaced, were mounted in my vehicle, not just sitting there. It is not beyond the scope of possibility that APRS actually hurt me in this case -- as someone tracking my vehicle could have just figured out where I was parked, and gone from there. This, however, would suggest that theives knew what they were looking for. I'm thinking that wasn't the case, though, by the fact that the main body of my Yaesu FT-8800R was stolen, and the control head for it wasn't -- each peice useless individually.

So as I think about doing APRS mobile once again, I'm thinking about the following:

1) Unit must be self-contained. I could use a TinyTrak and a mobile radio (or even a hand held radio!) but I'd want to do so in a self-contained unit, like I had before.

2) Can't replace my current VHF/UHF rig. I've tried using APRS on my FT-8800R while using the other "side" of the radio to listen to the storm net. This is all fine and good, until I have to transmit, as I have to change sides, and hope that the APRS box doesn't beacon while I'm on the repeater. As I like to listen to two nets out on storm spotting, and don't really want to buy another mobile rig that doesn't support D-Star, the Kenwood D700/D710 is out.

I've decided to go with a TinyTrak4, coupled with a FT-2800M that has not had any real purpose since I moved my FT-8800R from the car to my dorm. I will most likely fashion a box to contain the radio, TT4, and also a power relay to switch the whole unit on and off with my ignition, much like I had before. I don't know if I'll mount the unit in my car yet or not. I probably should, however. The TT4, and GPS should be here soon (edited 8 April 2008), and I'll post an article of the build process.