Today I brought out the Garmin 430 unit so that I could test my wiring. This is a bit of a stressful moment, since the unit is very expensive and I ran all of the wires by hand. I powered the circuit with fuses and used my meter to re-verify every single pin to be sure that power was only applied on the power input pins and that grounds were only continuous where they were supposed to be. With nothing else to test, I put in the box and turned on the switch.
Thankfully, it worked and didn’t start smoking. I ran a few initial coax cables for the antenna feeds, and designed a method for mounting the cat whisker VHF navigation antenna in the vertical stabilizer. I’d like to be able to remove the antenna once the covering is in place, so I will need to have a large enough hole in the covering to allow access to the mounting bolts. This H-shaped arrangement will give me a good hard edge to end the covering on, and a place on which to mount an aluminum hole cover.
The antenna that I found had a little bit of wear in the solder joints on the balun, so I fabricated a new one out of RG-58. I measured the original and made the new one to match.