This is about a VHF radio in a plane with a headphone and microphone jack.
I currently have one comm radio with a harness to the pilot mike and headphone jacks as shown, with a standard separate push to talk (PTT) to the throttle handle. One of the goals was to be able to listen to both at the same time. I did find this on a cursory internet search:
Quote:
The outputs of two pieces of audio gear cannot be combined directly without circuitry to prevent loading of one by the other. If you are trying to combine the headphone outputs of two pieces of portable gear, you can make a mixer yourself by running each channel of both devices through a 10ohm resistor of 1/2 watt or more. You can place the resistors in-line with the "hot" leads of the wires of a "Y" adapter if you're in a DIY kind of mood.
So if I added the 10 ohm resistors to the headphone input of each radio afterwhich combining them, then used HF's schematic for the rest, would that work with the switch choosing which radio was primary and which was listen only?

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