12 volt heater/filament tubes Dual Triode, Medium-mu, designed for use in equipment having series heater-string arrangement.
TRIODE-PENTODE TOSHIBA VACUUM TUBE 10KR8 NEW IN BOX
12 volt heater/filament tubes ECC81, 6060, B309, M8162 ,GE6201 High-mu dual triode. Commonly used as R.F. amplifier/mixer in VHF circuits.
VACUUM TUBE