These are easily my favorite Exciters to rebuild, the Broadcast Electronics FX Series.
30(left) and 50(right)
Not much difference between them other than power output and cosmetic changes.
The FMO module on some units is potted. There are four electrolytic caps in there that might need replacement. This one still operates correctly, thankfully. It takes several hours to access those potted caps.
This one did NOT still operate correctly:
Another FX series FMO module, this time with the caps burst, leaving electrolyte on the PC traces. This one took some work to clean up and repair.
BE does still have these FMO modules available new. About $700, making it worth the time to repair.
Power supply regulator on the left wall, AFC module, FMO and far left- RF power amp. These exciters take only a few minutes to disassemble, making repairs fairly easy.
There is a DC Pass transistor on the rear of the RF amplifier that tends to fail. I replace it, along with all capacitors and the cooling blower. None of these units are young anymore, but they still perform very well.
One final upgrade is to replace these jumper headers with DIP switches. It’s a simple matter of unplugging the jumper blocks and plugging in DIP switch blocks. It makes the units easily frequency agile once you figure out the odd coding scheme. Don’t forget to add 10Khz…