APRS v1 Page 1

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Back to APRS

Intro

After much thought, I've decided to get into the digital side of amateur radio, since at the moment, HF DXing is out of my reach. So after looking at the options, I found the most inexpensive way to get into APRS was the "TinyTrak3" unit. For a "built it yourself" project, it has a lot of neat features. It supports the AX.25 protocol, with the ability to decode $GPRMC or $GPGGA gps sentances, and then create a packet with lat, lon, alt, heading, and speed. It also supports MIC-E (which I think is a very cool thought, if it could be more widely implimented at the RADIO level. And I think the think that got me the most was that it had a PALM application to configure the tracker on the fly. The tracker itself only draws a few milliamps (with the leds off... about double and some for the leds on), and supports the ability to switch on and off a radio to save on recieve power. This could let this APRS system work on a very small battery system.


TinyTrak3

This is what the Tracker looks like fully assymbled per instructions:
http://www.whuckaba.com/aprsproject/tinytrakcase.jpg

And here is the circuit board:
http://www.whuckaba.com/aprsproject/tinytrak.jpg

More information on this tracker, and links to buy can be found at The Byonics website They also feature a weather station board for weather station APRS. (I hope to do that some day when I get my own place). Again it employs a very low power consumption feed. Here is " typical data set available from a weather aprs station

Can't Leave Well Enough Alone

Of course not! It's amateur radio after-all. If I am going to build it myself, why go with the traditional when I can customize it for my own usage. I keep debating if I want to build it to spec, and put it in a custom enclosure with the connections I want (With connectors to interface with the original design specifications), or to completely customize the layout.

The big issue I have is cabling from the GPS to the TinyTrak. The garmin serial cables are overly too expensive, and I already have a perfectly good cable system for my Palm:
http://www.whuckaba.com/aprsproject/cable1.jpg

So I sat down and determined how my connectors worked:
http://www.whuckaba.com/aprsproject/connections3.jpg"

And then drew a few connection deatils.
http://www.whuckaba.com/aprsproject/connections1.jpg
http://www.whuckaba.com/aprsproject/connections2.jpg

Then I drew a sketch of how this would all interconnect with the ttk
http://www.whuckaba.com/aprsproject/drawing1.jpg"

And then I modified the schematic to give me an idea of what I wanted to do with it all.
http://www.whuckaba.com/aprsproject/TT_S.JPG


So keep tuned to see what changes and modifications to this vision I adopt as I move forward in the tracker. AT the moment I know the primary tracker radio will be the IC-02AT, although I want to provide provisions to use the IC2350H as well.

The other thing is I wanted to be able to archive the data I send out. Stay tuned for the maps I have created, to find out "where in the world I am". Or at least the US. :) Also I will eventually write a webpage about WHAT APRS is.