Hello!
So I want to have a separate line-in for my uBITX, separate from the Mic input.? I also want to have a separate PTT.? The intent is to have the regular mic/PTT plugged into the front of the radio, and then also have the computer hooked up in the back.??
Requirements/Constraints/Desirements:
- Always keep the computer plugged in.
- Always keep the mic plugged in.
- If the mic PTT is pressed, don't transmit computer audio.
- If the computer PTT is asserted, don't transmit mic audio.
- Don't require a mechanical switch between the inputs (I have a fairly compact case and don't have room for more switches).
- Don't require a relay*. (* This is not a hard requirement, but I'd rather not use a relay if I can help it.)
- Don't require use of any Arduino pins (I'm using parallel display, don't have anything available.).
I was looking at schematics for some old Ten-Tec Omni V rigs, and saw the diodes in the transmit audio line, where a pair of diodes was alternately forward/reversed biased to route the audio either to the speech processor, or not, and I thought, maybe I could use a similar diode arrangement to enable just the audio from the mic or the line-in... except that they switch the bias voltage to the diodes via a front panel switch, so still a problem to solve.
So my thought is, in the "default" configuration, only the Mic audio would be routed to the uBITX.? But, IF the rear panel PTT was activated, then only the Line-in audio (for as long as the rear panel PTT is activated).? Any thoughts on a circuit--preferably simple :-)--to achieve this?
Thanks!
-Rob KC4UPR
