David's TinyTrakII

Here are some pictures I took of my TinyTrakII, a kit from Byonics for doing mobile APRS. It comes as a kit, and interfaces between a GPS receiver and a radio transceiver (no TNC needed!).

To see my recommended configuration settings for the TinyTrakII, click here.

Click here to go back to David's APRS page.

Altoids Tin, Version 2

While my original Altoids tin mounting worked okay, having two cables attached to it was a bit much, it lacked a primary/secondary selector switch, and I wasn't sure one of the DB9s was always getting a good connection (the female DB9 installed from the inside of the tin prevented the mating connector from fully seating). Also the blinky lights were always visible and conspicuous, which was not always desireable.

So I whipped up version 2. I put all the required signals on one male DB9, and had just enough pins to allow each of the 3 pigtails had it's own ground (without having to bridge wires inside the cable's connector). The connections are, in no particular order:

To mount the TT2, I glued three flathead screws to the inside of the tin. On the previous version the standoffs had screw heads coming out the back of the box, which wasn't very clean and I couldn't just slap some velcro or magnet strips onto it. I used some short aluminum spacers (short tubes) to space the TT2 off the bottom of the tin.

In the interest of space, I also removed the on-board DB9. I couldn't get a cable on it without removing the TT2 from the tin, anyway. I built myself a cable which provides power and serial data in the right places just for programming of the TT2. I use a different cable when used in-vehicle.

Since I have a steel console with flat surfaces, I simply attached some adhesive magnet strips to the bottom of the tin. I can slap the thing on top of the console and open the lid if I want to see the LEDs. Or I can slap it onto the rear of the console when I want it out of the way.

The switch is DPDT center-off. Down selects my "primary" configuration, center is off, and "up" selects my "secondary" configuration. Sometimes I use the secondary config for an experimental setup, leaving primary at "known good" settings. For example, I tested with increasingly aggressive (shorter) TXDELAY settings on secondary until it stopped working, then I could flip back to primary until I was able to pull the unit out to reprogram it.

Screws epoxyed to the tin
Note standoff on upper left screw

Almost ready for install into tin

Finished, in vehicle

Cable from TT2 splits to 3 pigtails
(power, GPS, radio)

Alinco DR-1200 under seat

Rat's nest of wires

Adhesive magnet strips secure
TT2 to steel console

Typical operating location

Altoids Tin, Version 1

Completed board

Solder side

With cables to power,
radio, and GPS

This might fit!

Cut-and-try method

Board mounting holes

It does fit!

GPS on left, everything
else on right

Starting holes in lid

Dabbed some sticky stuff on
LEDs to mark for holes

3 holes done, and you can see
sticky spot for 4th

Need to enlarge holes

Tapered reamer did the trick

Powered up!

TinyTrak and DR-1200 on
vehicle's floor

Need to work on a better install

GPS on windshield frame - works
through Jeep's fiberglass top

Email the webmaster: ky0dr at arrl dot net