Designed for use in the audio-frequency power-output stage of radio receivers. New old stock * No longer available for export. MFR: Raytheon, GE SKU: 50C5
Designed to be used in line operated equipment having series connected heaters and the heater is tapped to permit use of a lamp. New old stock * New in Box * No longer available for export. MFR: GE, RCA, CBS SKU: 50DC4
Designed primarily for grounded grid operation in the input stage of broad band amplifiers. New old stock * New In Box * No longer available for export. MFR: Raytheon, RCA SKU: 58-Remote
Designed to operate in the out put stages of audio amplifiers designed to operate from transformerless AC or AC/DC power supplies. New old stock * New in Box * No longer available for export. MFR: Dumont, Tung-Sol SKU: 60FX5
