[nbachert]

I've been working on this harness for about a month now and I'm unable to get the VOX or the mics to work. I can hear my dynon system and radio calls on both radios as well as see the tx when I engage the ptt button and the light changes colors on the intercom. I worked with dynon for a while and then sent it back to them and they said it worked ok. I got it back today so I rebuilt the harness and it is still doing the same thing. I can hear everything but no mic functions. I have all the wires daisy chained together except for the mic grounds which have their own designated ground. I talked with an avionics guy and he told me to check the mic jack to see if it is grounded and when I checked them they were. I removed them from the mount to make sure they weren't grounding at the panel but when checked with my ohm meter they still beeped. That means that they are grounded somewhere in the harness but I don't understand how they are and the headset jacks are not. Has anyone had issues like this or know how I can get this to work. Thanks,

Nick

 

[BobTurner]

The most obvious mistake might be mis wiring the mike jack. The mike wire goes to the ring, not tip, terminal.

 

[nbachert]

Huh?

Bob, I'm not sure what you mean so maybe that is my problem. Dynons manual shows the 3 wires going to the three terminals and then the ptt wires also on two of the terminals. Are you saying that one of the wires doesn't attach to a terminal?

 

[az_gila]

The most obvious mistake might be mis wiring the mike jack. The mike wire goes to the ring, not tip, terminal.

This might help - from Aeroelectric Bob...

 

[BobTurner]

Look at a mike plug (male). There are three parts: the tip, then a ring, then the barrel, or ground sleve. Put this plug into the jack so you can ID the corresponding terminals on the jack. Use an ohmeter if necessary.
The 'hot' mike connection is the ring terminal. The return is via the barrel or ground sleve. The tip connection is for PTT. Most builders do NOT connect the PTT wire to the jack, unless they plan on using a portable PTT switch in the jack. Most people wire the PTT wires to a push button on the stick.
It is good practice, for noise reasons, to run a wire from the barrel to the intercom ground, and at the same time isolate the jack with fiber shoulder washers so you do not use the airframe for the ground, but this will not cause the unit to not function at all.

Edit: see Gil's photo, above, to ID terminals