50B5 Beam Power Tube. A miniature radio tube by RCA, U.S.A. #21002 | M-Ware
50B5 @ The Valve Museum
Vintage+NOS+RCA+50B5+Vacuum+Tube+Tubes+USA+Tested+Tub20044 for sale online | eBay
5 Vintage ITT 50B5/A4388 Miniature Tetrode Audio Output Valve - BangyBang Tubes : Amazon.ca: Musical Instruments, Stage & Studio
5-Buck Amp
50B5 Beam Power Amplifier Tube. Designed to be used in the output stage of compact AC-DC receivers. MFR: GE, Westinghouse, Sylvania. SKU: 50B5. New old stock. No longer available for export.
Tubo a vuoto Tung Sol 50B5 per radio da tavolo a tubo nuovo - Etsy Italia