Apache Labs Community Forum

Could someone please help me figure out the following issue with my G2 w/front panel screen.

I have a headset with mic that uses a 3.5mm mono plug. Plugged into the front panel no audio with the TR plug and no audio with a breakout TRS plug in which the TR plug is inserted in the ring socket. Using Thetis Protocol 2 I experience the following:
1. If I plug the TR plug into the rear socket next to HP socket, it keys MOX and the audio is fine.
2. However, if I use the breakout adapter to avoid keying MOX then no audio.
3. If I add a ¼ RCA TRS adapter to use the so-called XLR socket no audio as well.
4. The front mic socket does not work with the headset mic using the TR plug or using the TRS breakout plug.
If I try all these combinations using only the front panel controls the results are the same except option #1 no longer provides any audio as well.
So I have not found any way in which to use my Heil headset with any of the 3 available mic inputs except using #1 with shorted PTT. Could someone please help me understand how to configure this mic with the G2?

The only mic I have that works is an old D-104 for which I wired a TRS 3.5mm plug, and that only works in the front socket; both rear panel sockets are inoperative with this mic.
Bill Diaz has been very kind in helping by providing diagrams of the pin outs for these various sockets, but they just don't seem to work with my mics.
Thanks in advance for any help.
-- Bob - Ki1n

Upon further discussion with Bill Diaz and retracing all possible connections, I found that the Heil headset required the PTT switch to be connected in the TRS breakout adapter to apparently provide a ground path for the audio.

Here is the breakthrough—using the PTT switch solved the problem. Apparently the Heil headset is wired to depend on the ring path to ground. If I unplug the PTT switch, no audio using MOX. Since I followed your suggestions implicitly, I used the PTT switch which I hadn’t needed to use previously because I was using MOX on Thetis. As soon as I used the PTT switch, I had full audio from the headset on the rear panel. Of course, it also worked fine on the front panel connector when reversing the breakout connection.

I hadn’t even considered that the commercially made Heil headset could be an issue, but I guess since this is the ProSet IC wired for the 7300, they could take a shortcut in the plug wiring.
Thanks to Bill and others on the FB Apache forum for their valued assistance in troubleshooting this somewhat complex issue.
73 -- Bob - Ki1n