Tuesday, October 27, 2009


Ok, tonight has been frustrating. It seems I got a little turned around with my serial soldering and I put my power leads in the wrong places. The bad thing is that I had to really test my contortionist skills and fine motor skills while soldering in an incredibly tight area without melting other wiring. Well, I got it resoldered just fine though it took some precious time.

Now on to the grand finale. After getting it put back together I went for the 2nd power test of the evening. Who let the smoke out? It would appear that if you accidentally solder one of your diodes directly to your power lead you exceed the diode's ability to retain its smoke.

So I guess I'll be calling Radio Shack tomorrow to see if they actually stock the 1N4148 diodes or if they're online only. I really hate to wait any longer. This is taking much longer than I'd hoped. :-/

Sunday, October 25, 2009

TinyTrak Version 2 Pt 2

I have all of the components in place that are directly on the board. I have the LEDs mounted (temporarily) in the case. Unfortunately I don't have #20 hookup wire so I'll have to get some tomorrow to finish. I'll use #18 for power but the LEDs and various switches should be fine with #20.

I'm a little bummed that I didn't get it done tonight but it's not a big deal. At least I got to melt a little solder. :-)

Saturday, October 24, 2009

TinyTrak Version 2

I got the new TT3 on Thursday and I've spent the past few days laying out my next design and getting or scavenging the components I'll need. I'm taking my time with this one to make sure I've got a robust and clean implementation. I've been doing some local testing to verify my theories and so far I'm on the right track. I spent today getting the case ready and I hope to start final assembly and testing tomorrow.

I also have to say that I'm impressed with the GPS2. It locks on very quickly. It's certainly faster than the eTrex at signal acquisition. I do wish it had a slightly longer cable. At 6' it just barely reaches where I have my current TT3. This should change once I implement the next version but even another foot would be nice.

Wednesday, October 21, 2009

More Traking

Well, the mind is flooded with mods and other build changes I want to employ with the TinyTrak3 so I've ordered another one. Byon just sent me the shipping notice so I should have it tomorrow. I still need to make some drawings and circuit layouts so I don't leave anything out so it might take me a little longer. Hopefully I'll be able to build it out with parts I have laying around aside from the case.

I also ordered the GPS2. I think I'm ready to go to a more "permanent" GPS solution instead of using my eTrex. Besides, I'm tired of changing out AAs. Stay tuned for more updates.

Monday, October 19, 2009

TinyTrak: The Ugly Mod

When I say ugly, I mean ugly. I'm even embarrassed to post pics. Ok, so here's the problem. Once again I faced the challenge of dual-use. At the moment I have my eTrex Legend feeding the TinyTrak. However, rather than continuing to eat up AA batteries I want to replace it with a standard 5V hockey-puck GPS. However, I want to retain the ability to use the Legend or even my 60CSx. My fear is that if I did a solder blob at J7 that feeding 5V to the GPS might smoke it if it's not expecting it. I haven't looked at the Garmin pin-outs to see if they can take 5V on pin 4. What to do?

Well, ingenuity struck again and I decided to solder a common dual-pin jumper to the pads so I could add the jumper when I needed to have 5V powering the GPS or remove it otherwise. Unfortunately the solder pads are very close together. Oh well, no worries with my expert soldering skills. I quickly knocked the mod out, tested it, and went to put the case back on. That's when I realized my fatal design flaw. The pins were too tall and the case didn't fit. That's when I caused my real fatal error. While trying to jimmy the jumper block I popped it off when one of the solder pads came free. Crap! Let's say the wife had to come out to see what was going on.

I tried in vain to do a repair. I pulled out the magnifying lamp and a fine Xacto knife and started scraping away at the trace for the pad I pulled. That's when I realized it's a very short trace and only went to the pin on the IC. Brilliance struck again when I figured I could just make an ugly fix with a wire jumper. I took a piece of wire lead from a resistor and solder that first to the good pad and then to the jumper block. My does this look like the worst repair I've ever done but it works. It may be ugly but I still have 5V when jumpered.

I doubt I'll go back to clean it up later. I figure I'll use it like this until I smoke it (and hopefully not anything else) before I do it right. Of course I'm not sure what "right" is going to be now.

This is the ugliness jumpered for 5V to the GPS.

See? I'm not lying. :-)

And here it is unjumpered for no voltage on pin 4

And finally, wrapped up in the case (which now closes properly again)...

Saturday, October 17, 2009

JOTA Update

Well, today was the Scouts Jamboree On The Air. A couple of us arrived at around 7:30am to get ready for the Scouts at 8:30. Of course, they were early and we had 15 or so Scouts before 8. No big deal. It actually worked out well, I think. They pitched in and got hands-on training in assembling and erecting antennas.

I'd say we had an easy 40-50 Scouts (including Cubs, Weebelos, and Girl Scouts) throughout the day. I was disappointed that the media didn't show up but I guess you can't have everything. We ended up with three stations (2 voice 1 digital). I was running the digital station and unfortunately the G5RV I put up didn't work at all for me. I had problems using the same antenna at Field Day so I've decided this isn't the antenna for me. I ended up building a 80M off-center fed dipole on-site and tuned it up on 20M. It worked great and in no time I picked up Canada and Mexico.

The highlight of the day for me was seeing the excitement on the face of a 6-year-old Tiger as he made his first PSK contact with a very patient Canadian station. Hats off to Colin for being willing to wait for some slow typing as he asked several questions.

Looking forward to next year!

Friday, October 9, 2009

TinyTrak R8 Mod

Well, I ran into a bit of difficulty this afternoon when I tried to use my new TinyTrak with my FT-60. As it turns out the cable that I use with my Piccon also works with the TinyTrak. I was excited to be able to use the HT instead of carrying my spare FT-8800 around in the truck. Unfortunately the TT3 wouldn't key the radio.

I just chalked it up to some misconfiguration between the radio and the device. I read through the manual while waiting to get my hair cut and didn't see anything out of the ordinary. No funky menu settings I may have missed other than disabling Rx Sleep.

When I got home I checked the Byonics site and looked up the cable again to confirm that it should work. That's when I saw the problem. With the cable for the mobile I had to leave R8 out of the circuit. In the description for the HT cable it says that R8 has to be IN the circuit.

Byon actually addresses this scenario and describes adding R8 to your cables. Well, that's all well and good if you're building your own, but I was using one of his. So what could I do? Well, the lightbulb went on and I used the same solution I've used for other kits where I needed removable components...I added a single in-line package (SIP) socket where R8 goes.

Now if I'm using the HT I insert R8. If I'm using the mobile I remove it. This is what it looks like configured for the HT. I had to bend the resistor leads a little and lean it over the pots to get the top of the case to fit but there's plenty of room now. I tested it and it works great.

I'm pretty happy with myself and the mod. :-) See ya on APRS!

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.