I did a bit of reprogramming of my ID-O-Matic IV controller tonight. Minor stuff; changing ID and EOT beep speed, COR polarity, etc. Connected a short section of phone cord to carry mic and PTT signals to the front panel of the TK-805D I'm using for transmit. There are only 4 wires in the phone cord vs. 6 in the mic cord, but it plugs in and only 4 wires are needed, so it works. Actually it would work with only 3 wires: PTT, audio+ and ground.
I cleared the memory on that particular radio and reprogrammed it for repeater use. Also turned the power down to 10 watts to up the duty cycle.
I've tested it by jumping the COR line and listening to it on another radio. Everything's working fine.
Now for the receiver portion. I found a guy on ebay advertising programming on a variety of radios, including the GE Phoenix. I've been in touch with him and he says no problem. So I'm planning to send him my Phoenix to be reprogrammed. I've tested the Phoenix and it powers up, receives, PL works, sounds fine. The only problem is it's currently on the wrong frequency. So when I get it back it should be good to go.
That's why I changed the COR polarity on the controller, in fact: I was originally planning to use another TK-805D for receive. COR is active low on the 805; active high on the GE. The GE is a much better choice for the repeater. All connections are external, no mods necessary. And being a two-channel radio, it's not much good for anything else. So that will free up another of my TK-805s for vehicle or base use.