6350 Sylvania Hewlett Packard black plates “”D”” getter halo tests like new 1950”s

faded printing in white box

1 section) 12.6ma Gm=5200

1 section) 12.8ma Gm=5200

Tested on Amplitrex

Vplate=150V

Vgrid=-5V

Good Ma per section = 9-11ma

Good Gm per section = 4500-5000

Recommended for

– VTL Wotan MB1250, VTL MB450, VTL MB300, VTL 225 Deluxe, VTL Deluxe 140, VTL Stereo 120/50, VTL ST150
– VTL Siegfried
– Joule Electra LA-150 (mk2)

– Joule Electra LA 100

– Shindo-lab Corton