What if we could down size the equipment? Or better still, reduce the number of pieces of equipment? Well that's where my latest project comes in. I have collected together some of the components of an APRS™ system and attempted to make a single 'black box' device out of the whole lot.

I started out with a little known kit made by Kantronics. This TX only radio is a 2 watt transmitter with facilities for a receiver should you wish to add one. I say this kit is little known as Kantronics made a few for a APRS™ day held by AEA/Timewave a few summers back. The kit has since stopped being produced and Kantronics is selling off their remainder stock. I bought 10 for $200 ($20 each). The remaining kits have some parts missing however and the manual is VERY bad. So bad in fact that it neglects to tell you to insert Q2, the PA transistor (!), and has an addendum page telling you to install transistor Q6  but still leaves out the PA.

The modem is an N6BG TinyTrak. Again this is a kit based on a PIC 16F84. The PIC accepts the serial data from the GPS RX and send out the position data according to its timer settings. I bought 10 of these for an  APRS™ project for the New York Marathon and had one left over. The cost was $20 (normally $25).

The GPS receiver is a refurbished GPSTripmate unit from DeLorme. They are selling them off at $50 a time. I had to do some modifications to convert it from a bespoke into a generic device but that wasn't too hard. Just a case of moving 2 wires inside and supplying power. The GPS RX is plugged into the modem which is in turn plugged into the transmitter.

$20 +
$20 +
$50 +
$07 =
$97!!