1 matched pair) 6B4G Raytheon NOS 1940's - separate plates - same build - 1 tube branded Tungsol

1 tube) 100ma Gm=6350 Raytheon 1940's

1 tube) 109ma Gm=6800 Tungsol 1946 - slightly taller bottle

Test Data:

Vplate=225V

Vgrid=-30V

GOOD NOS Ma range 70-90ma

GOOD NOS Gm = 5200

Recommended for

(6B4G=6.3V filament)
(6B4G is electrically equivalent to 6A3, but 6A3 has UX-4 pin base and 6B4G has 8 pin octal base)
(The best sounding 6B4G are 1940's-1950's: Ken Rad, Tungsol, Sylvania, Raytheon)