Ok guys,

I have an electrical question regarding a Garmin SL30 and a SoftComm ATC-2P Intercom.

Things aren't quite happy working together so I spent the day verifying connections and making sure each wire goes where it is supposed to.

The problem comes when I key my mic button to communicate, all I get is a heavy feedback/staticy garbled sound.

Now my headphones work somewhat correct with the 2 components. My problem with the headphones is it appears that the Pilot only switch position vs the pilot and Co pilot switch position appear to be working backwards. I reviewed the wires and they are per the drawings from Soft Comm. ( I will be calling them tomorrow!)

Soft Comm Intercom

So during my review of the schematics, for the Panel mount intercom for the mic problem, there is a Power ground and a Radio Ground. What are the differences between these 2. Is the Radio ground different from the power ground? Do both go to the airframe or does the audio ground remain isolated from the Power/frame ground?

During the review of the SL30 pin descriptions, there is an audio ground, a Mic ground and a power ground. Same question! Are these to be isolated from each other?

There  is also an audio ground for the SL30. Is this or can this be ran as the same wire as the mic ground? IT seems the Softcomm intercom merges these 2. These all seem to merge at the outer sleeves for the connectors both Mic plug and Headphone plug.

For the SL 30, there is a TX Key "connection" with a described function of; "Transmit enable key, pulled low to transmit". IS THIS for the PTT button on my stick?

I hope this makes sense. I can follow electrical road maps usually without a problem. In this case, the different terminologies confuse me.

Thanks for any help!

Rich Simmons