A quick way to know if the RXTX is being keyed by the PTT signal is to measure the voltage on the hairpin of R35. The is the "S12" signal and it will be 0 volts in receive mode and 12V in transmit.
Another quick check if your 12 supply has a current meter is you will see the current draw increase go up dramatically when you switch to transmit.
But make sure you set up Rocky correctly first!
Warren Allgyer
W8TOD
Warren Allgyer