[MRCA] Retransmit

[Chance Wolf]

> 
> So, according to the Harris list, the PRC-138 does support Retrans via a simple point to point cable. I had a quick look through the manual and while there appears to be no instruction or description of operation page - the front panel audio connector pinout near the end of the manual does show Retransmit on one of the pins. I'd copy over the pertainent info but I'm mobile at the moment.