vt50 hl2k hl2 tube nos Marconi Osram Gec pair tubes pre amplifier silver mono plate ribbed Royal British army Admiralty A.M.
2 tubes vt50 hl2kBritish valves mil specs
silver plate
mono plate
ribbed plate
silver foil getter
straight shape
military edition
tested strong 9,2mA for each tube (reference good at 4,2mA) on tube tester funke w19s