Batboard

Hi somewhat new here...been around awhile but have forgotten all my old PW and user names. Anyhow Im having an issue with a spectra PTT circut and I dont have access to a service manual. Seems as though it has exciter power as I can see RF on the monitor however the PA dosent come up. I swapped out controll and MLM board with a known working unit and it works fine, ruling out any RF amp/vco issues. So with that I am suspecting the transistors/fets along the back of the logic board that attach to the frame with the metal clip. If I am indeed correct wich one of those 3 or do all of them enable B+ for the PA power amp section? Secondly whats the part numbers so I can order replacements. Thanks!
Jeff

Mraudio wrote: I am suspecting the transistors/fets along the back of the logic board that attach to the frame with the metal clip. If I am indeed correct wich one of those 3 or do all of them enable B+ for the PA power amp section? Secondly whats the part numbers so I can order replacements. Thanks!
Jeff

Those are voltage regulator transistors. The keyed 9.6 and the power control comes from transistors on the bottom of the command board.

Thanks Ill take a peek later. Looked like the traces went to the back edge connection where the PA jumper cable plugs in. What I get for assuming
Jeff