valve, tube, thermionic, electron, triode, tetrode, pentode, power, magic eye, tuning indicator, nixie, history, data, data sheet, specification, amplifier, radio, octal, B9A, B7G, B4, IO, KT88, KT66, 12AX7, 12AY7, 12AT7, ECC81, ECC82, ECC83, 6L6, 6V6, EL34, EL84, EM34, EM80, EM81, EM85, Mullard, Triotron, GEC, Gold Lion, Marconi, Svetlana, Brimar, Ferranti, RCA, Sylvania, GE,6202, amperex, arcturus, brimar, channelmaster, colvern, cossor dario, debanks, edicron, ediswan, ei, elpico, emi emston, era, eratron, ever-ready, ferranti, ge, gec heinz, kaufman, haltron, hivac, hrs, itt, jackson lamba, lorenz, marconi, mazda, mullard, national, osram philips, rank, raphone, raytheon, rca, rft, selectron sovtek, standard, svetlana, sylvania, telefunken, tronix, tungsram united, valvo, westinghouse, zaerix