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, Cossor, 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
PX4
This directly heated triode had a long career. It was
in production from the late twenties until the mid fifties. The
performance, especially the anode dissipation improved slowly
over time, as the design as improved. These valves are still
much sought after by the single ended triode amplifier enthusiasts
and this is reflected in the high prices achieved for NOS examples
on E-Bay. A single valve can produce up to 3.5 watts of Class A power.
This Osram example was probably made just before WWII.
Here are PDFs of the data sheets from the 1938-1939
Osram Valves handbook - page 1,
page 2. If you want lots more about
the PX4 then go to the excellent px4.org
website run by John Pinner.
