56 National Union engraved base used/tests like new 1930”s (6.0ma)

56 National Union engraved base used/tests like new 1930”s

6.0ma

Gm=1500

Tested on Amplitrex:

Vplate=250V

Vgrid=-13.5V

Iplate good range = 4.5-5.5ma

Good used Gm=1200-1300