Opening up a clean TS-505 D/U vtvm. Anyone have any experience with these? My meter powers up, all 4 fuses are good. Meter shows an attempt to fluxuate. But no zeroing or other life. Has two 5651WA tubes which may be military version of OA3 (??). Any memories anyone ? TIA, Doug Visit https://www.qrz.com/db/W5JV for some great vacuum tube finds.