Atikokan Amateur Radio Club

Serving amateur radio operators and
providing emergency communications for Atikokan and area


All material copyright © Atikokan Amateur Radio Club
E-mail: VE3RIB@shaw.ca
Snail mail: P.O. Box 2106, Atikokan, Ontario P0T 1C0

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VE3RIB repeater
Atikokan, ON
147.120 +

VE3RIB-1 digi
Atikokan, ON
144.390 (APRS)


VE3RIB-2 digi
Flanders, ON
144.390 (APRS)


VA3EOA station
Atikokan EOC

VE3YIB station
Atikokan Airport

Broadband HAMnet

APRS on the Cheap

By Warren Paulson, VE3FYN

This article will show you one way to setup a computer - radio APRS rig. It may be a home station, or a laptop. It uses a very simple sound card interface using parts you can likely find around the shack.

Requirements

For this  approach, you will need a computer with a sound card, a two metre radio, and a few spare parts you  should be able to find in your junk box. Some are optional, but will improve your signal quality. You’ll also need to download some software.

The computer

Any Windows computer will do, if it has  a working sound card. If this is going to be a permanent setup, you should  consider a second sound card dedicated to APRS. This will reduce the number of times you have to fiddle with the settings, and ensure that various Windows sounds don’t  get broadcast. USB soundcards can be had for as little as $11.

The radio

Do not use an expensive radio. It will only be operating on one frequency (144.390 Mhz) anyway, and will not be using all the fancy features of most amateur rigs. A re-purposed commercial radio is best. This article describes using a GE-MVS, which is commonly available on eBay for about $50. The GE-MVS is described in detail elsewhere on the site.

The other parts

At the very least, you will need an N-channel MOSFET that is fully saturated at five volts. I used a Fairchild #BS270 (Mouser Part number 512-BS270). At Mouser.com,  these are currenly 12.8 cents each,  so buy lots. If you can, a pair of capacitors roughly 300 nF are helpful but not essential. You’ll also need a female nine pin serial plug, and if your computer doesn’t have one, a USB to serial adapter. Aside from that, some wire, solder and such, and you’re off to the races.

Software

Of course, you’ll need software to make this all work. That will be detailed later, but we’ll use AGWpe to interface between the computer and the radio, and AGWtracker as our APRS program. UI-View is also a good choice for APRS software.


Let’s get started…