Wednesday, October 7, 2009

APRS Goodness

After much consternation I finally jumped in to the APRS world. I have a Yaesu FT-8800 in a mobile go-box that I figured I could use to put my signal on the air. I also realized I have a Garmin eTrex Vista that I'd been planning on getting rid of but I could use it for the project as well. So $50 later I had a Byonics TinyTrak3+ in my mailbox.

The instructions say it should take about an hour to build. Took me about 2 hours but I spent a lot of time fiddling with the camera.





It's aliiiiiiiiiiiiiiiive!! ;D

I remembered I had some power stuff from my General class and I could use an alternate power connection. The pic quality sucks but you can see that the end LEDs are on.



OMG I can't stop! Once I had power I had to make sure I could read and write to it.



Unfortunately when I ordered the unit I forgot to order the interface cable to connect to my radio. Good thing I can make my own. Unfortunately I learned a hard lesson today. PS/2 cables are a pain in the butt to modify. First I learned that only 3 conductors are used. Second I learned that they didn't go to the pins I needed. With this gotcha I couldn't really make the simple cable I wanted to. I also found that if you cut the outer shell off with a Dremel you'll discover that they fill the pin area with plastic. >:( I used a butane soldering iron as a torch to melt the plastic so I could dig it out and access the pins to wire it was I needed. Once that was done I was off and running.

I got the mouse cable wired to the pins I needed to and then made a quick run to Radio Shack to buy an audio cable. That got cut in half and the raw end went to my new serial connector. Then I wired in the PowerPoles with 18# red/black zip line. Finally I heat-shrinked what I could as best I could to act as some strain relief. Unfortunately with so many cables coming out of the serial connector I can't put it in a housing. My other problem is the mini DIN. I put it back in one of the molded shells I cut and electric taped/heat shrunk it to give it some strength. It didn't work. It pulled out when I tried to remove it from the radio. I'll have to figure something else out.

Raw Serial Connections


Wrapped Serial Connections


Radio Connections


After tweaking my configuration I was able to test everything together. To my delight not only did it all work but I didn't smoke my radio either. Within about 10-15 minutes one of the guys was calling me on the air because he'd seen me pop up on APRS. I also used http://aprs.fi to confirm that I was showing up. I'm a happy camper.



I'm really looking forward to finding some cool uses for this. Eventually I see myself getting the more capable TinyTrak4 but this is a great way to get into APRS on the cheap.

1 comment:

jc said...

wow! i got menttioned in your blog!...well, not by name...well not by callsign either...but it was ME!!!

way to go...you need to document your mods and kit building more...it gives us the motivation to try it ourselves!

thanks...