Mitch
I might be inclined to agree with you, except for one big item- if I unplug the cable that goes from the RR Control unit to the TS480 head at the RR Unit, and plug it into the TS480 body, then the TS480 turns on and works. If you tell me that wiring is different between the two functions of that cable, I'll believe you and get the cable that you specified. It also appears to have all the 6 connections at both plugs.
Mike
You were partially correct- I was looking for the +8V at the jumpers for the MIC jack, not the TTL jack. So I turned the unit over, and behind the TTL jack there are two rows of 3 connections that look like they go to the TTL jack. I measured the voltages at each and this is the result (orientation is the pcb is upside down, and the two rows of connections have the top row, furthest away, with the first connection slightly to the left of the bottom row):
Top row, left most: 0V
Top row, middle: 0V
Top row, right most: 4.98V
Bottom Row, left most: .02V
Bottom Row, middle:" 5.03V
Bottom Row, right most: 3.01V
When I measured the ground connection was between the ground solder pad near the TTL jack, and again at the -DC input connector pad. In both cases, the voltages were the same. No 8V. Per your other suggestion, I made sure that it was in Mode 5, TS480.
Dennis W1UE