It has been a couple of weeks since I’ve been able to get back to work. I installed the rear audio jacks and created the d-sub connection that I wrote about last month. Since the three non-pilot jacks all share a common audio source, I had to find a way to connect several small wires in a mechanically robust way. Here is the solution:
The wires go from the cabin jacks to a crimped d-sub connector. That connector plugs into this soldered piece, which is sort of like a mini bus bar for each channel. The three connections are for the audio left and right and ground.
I mounted the intercom box:
Then connected the audio wires between the Garmin 430 and the intercom. I wired the push-to-talk switches in the sticks, which allowed me to run the final wire for the intercom. I powered it up and everything works well. Never before has it been so much fun to talk to myself! I wish I could say the same for the audio amplifier circuit that I built. It keeps blowing it’s fuse, so I probably put something in the wrong place. I’ll email Bob N. and see if he has any troubleshooting suggestions.