I've got hold of a pair of Racal PRC-6725 transceivers, (30-88MHz), they are effectively the PRC-139 I believe when sold in the USA.
Odd thing is both of them are low in frequency by about 3.7KHz on both transmit and receive leading me to think it's the reference frequency for the PLL that is off.
Would anyone have a service manual or schematic of the synth / pll section, the radio has of 2 PCB's stacked ontop of each other, and on the opposite side, an 'RF deck' which is a separate module, used I believe several Racal transceivers of the same era, there were also UHF and High band modules.
Googling has yielded zero so far, I know they are programmed from a dedicated hand held programmer, but don't know if the frequency can be adjusted from said programmer to get it spot on.