(!!!!) (Recommended Pair) 6C4C=6B4G Russian NOS 1963-1969 (86ma and 88ma) (these are some of the best sounding 6B4G ever made)

1 matched pair) 6C4C=6B4G Russian NOS 1963 and 1969 in white boxes 1 tube) 86ma Gm=6300 (1963)  1 tube) 88ma Gm=6400 (1969) taller glass Internal construction superior to American made 6B4G   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)