Log-in

(!) (#1 10 engraved base pair) 10 Sylvania "engraved base" 1930's used/good same build (21.5ma and 22.5ma)

$ 144.99

1 pair) 10 Sylvania "engraved base" 1930's used good - same internal build - in white boxes

1 tube) 21.5ma engraved Sylvania

1 tube) 22.5ma engraved Philco with "X" scriped on bottom of tube 

Vplate=300V

Vgrid=-15V

Good Ma range 20-30ma

 

General Information

(Filament=7V @ 1.2A, Vplate=220V, Vgrid=-7V, Iplate=25ma, Mu=6, Rp=6Kohms)

(The VT-25 is built exactly the same as a VT-52, but the plate and grid are spaced  differently yielding ifferent Mu factors and plate resistance)

 

See more: vacuum tube
Scroll to top