Nov 302009

So the August issue of QST had an ignition switch timer that was very easy to build and implement. I thought this was perfect for my car so I didn’t have to worry about disconnecting my OpenTracker+ and Icom 228 from power when I didn’t want to use it. There was just one problem, there was no way to make it optional; sometimes I don’t want to use APRS.

First a note about the parts list. There is a 10k ohm resistor (R6) that is not there, but shown in the schematic and PCB (if you order one from Far Circuits like I did).

Now, onto the problem of making my APRS optional. After perusing the circuit, my father and I thought best to dremel away the trace between Q2 and ground. The only concern is that the transistor would not like floating but we’ll test that further once it’s finished. After drilling new holes for the switch between the transistor and ground, I put the components to the board and everything looked good.

The next step would be to put in a 6 terminal rail in a large project box so I could control up to 3 devices with the timer switch. Of course, everything has powerpoles on it so I can quickly dis/connect devices and radios.

Final installation should be on Thursday before our Extra class and I’ll post up some pics of my handy work on Friday.