(!!!!) (Best Value Pair) 6B4G Raytheon NOS 1940's separate plates, 1 branded Philco (90ma and 91.5ma)1 matched pair) 6B4G Raytheon NOS 1940's separate plates 1 tube) 90. 0ma Gm=5850 Raytheon branded Philco same build 1 tube) 91. 5ma Gm=5600 Raytheon hairline crack in base see pic 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,