50 UX250 CX350 mono plate pair audio valves National Union Triad tested 100%

Description

Power valve triode type UX250 mono plate shoulder shape excellent good looking valves made in the early 1930s

The National Union has engraved letters on base whilst the Triad has yellow print.

Both UX250 50 have been tested at 54mA and 55mA with 100% emission