RCA 3V4 Radiotron Electron Tube – St. John's Institute (Hua Ming)
3V4 Power Amplifier Pentode Tube. Designed for use in the power output stage of compact, battery operated equipment. MFR: RCA, Zenith, Sylvania, Raytheon. SKU: 3V4. New old stock. No longer available for
20160227 Datasheet 3v 4 Battery Tube : General Electric : Free Download, Borrow, and Streaming : Internet Archive
Two Tube Broadcast Receiver: 1951 | OneTubeRadio.com