(!) (#1 231D - BEST SINGLE) 231D Western Electric 1948 with data sheet (2.7ma)
$ 129.99
1 tube) 231D WE NOS 1948 with 231D data sheet
2.7ma Gm=500 (813=1948)
Tested on Amplitrex
Vplate=90V
Vgrid=-3V
Good Ma = 1.6-2.1ma
Good Gm = 400-500
General Information
3V Filament @ 60ma, Vplate=90V, Iplate=2.1ma, Mu=8.4, Gm=510, Rp=16Kohms, Pout=4.5mW
Similar to UV-199 and 864
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