MGL Avionics User Forum

I really like that the V16 radio has the intercom built into it. One thing that I'm not sure if it would work for me is having the pilot and co-pilot on the same audio output. I'd like to install an isolate/mute switch for the co-pilot side to be able to listen to music without hearing atc. My worry is that it would change the volume for the pilot side depending on if the co-pilot headphone was connected or not. Is this the case or does the volume remain constant?

The V16's audio output impedance is 8 ohms (so it can drive a normal speaker). Aviation headsets are 300 ohms so pose effectively no load to the output. So if you have two headsets connected and then remove one you will not be able to hear a difference in volume.

It sounds like you want to add a change-over switch to connect the P2 headset phones to a separate source input (iPhone headphone output etc). As Rainier says, disconnecting one headset's phones from the V16 audio output will make no difference to the volume levels due to the low impedance of the output.
One thing perhaps to keep in mind (this may or may not pose issues) is whether you share the earth/ground or switch it with a douple pole change-over switch. If a phone is on charge from aircraft power and sharing an audio earth, there may be some potential for ground loops or currents flowing where they ought not. Depends on the phone/tablet/media player design.
Then the microphone signal line would ideally need disconnecting and the input to the V16 grounding to V16 ground otherwise there's potential for noise entering the intercom.
Unfortunately, for P2 to be isolated from ATC they're also isolated from P1 since there's a common audio bus output for both.

Good to know I don't have to worry about volume. I wasn't planning on a changeover switch since I've got Bluetooth headsets. Thus I think it would be OK to just leave the shielding/ground connected.

The only way I could come up with to be able to hear the other person on intercom without both being able to hear ATC would be to have two separate intercoms and to find a way to wire the output of each one to an input on the other. I'm sure you have to deal with getting the headphone level down to an acceptable level for an input and the extra wiring. All the other intercoms I've seen with an isolate switch with separate headphone outputs can't isolate just the radio without isolating the intercom.