Help with PTT circuit for icom radio
I don't know that it's exactly correct, but this actually seems to work.  It's a bit confusing to me as it seems quite a bit different from what I was reading above, but when I put it all together, it seems to actually function.

I tried lots of combinations basically poking around with wires until I got both audio signal and the PTT signal onto the radio before coming up with this.  It seems to be the answer, but I'd like a couple other opinions on it.