(!!!!) (Best Overall Pair) 6528 Raytheon graphite plates NOS and like new 1970 era (125ma/135ma and 119/129ma)1 pair) 6528 Raytheon graphite plates NOS and like new 1970 era same build original boxes 1 tube) 125 135ma Gm=25,500 25,000 like new but probably is NOS small amount of staining above edge of metal base 1 tube) 119 129ma Gm=24,400 25,000 NOS tubes branded CK 6528 boxes branded CK 6528A Vplate=140 Vgriod= 10 NOS mA = 100 120mA NOS Gm range 24,000 30,000 graphite plates