There are no negative voltages on the board, so perhaps your (-) meter lead is on the wrong trace which is not connected to the DC- ground.? Look at the ACC circuit schematic on the DDS board in the Service Manual (PDF page 89 in my version).? If you are measuring from the rear panel ACC connector, it is easy to get the wrong contact #.? It is easier to remove the top cover of the case so you can access the pins of the ACC connector on the board.? Look at the DDS PCB artwork on pages 69-70 of the manual.? The Bottom of the PCB is what you see with the cover removed.? The Top of the PCB artwork shows the signal names of the connector pins.? I would print the two and write in the signal names on the Bottom view, which is what you can access easily.? ?Measure the 14VA on pin 8 to the large ground plane trace to verify you have 13 VDC on it.? If not, it is possible that the ferrite bead EP1105 has opened up due to excess current.? See if you have 13 VDC on pin 3 of the TUNER connector, which is the 14VA signal also.? If you have 13 VDC on pin 8, meaure the SEND1 & SEND2 signals on pins 3 & 7 to ground in RX & TX modes.
Where you go from there depends on what you measure on those 3 pins.? But SEND1 & SEND2 come from RL1101, which is fed by the SNDL signal and the SDSS signal that control the relay's coil.? Without knowing how familiar you are with troubleshooting and repairing surface mount boards, I don't know how much more detail to provide until you redo the measurements of pins 3, 7 & 8.
Steve, W3AHL
Steve W3AHL