Largest vacuum tube ever made

[N2IXK]

Interesting. I wonder if this tube went on to commercial use, and was eventually assigned a type number?

As far as early tubes in the 100 kW power class, there were at least 2 other types. The type 862 was a 5 foot long water-cooled beast, which saw service (20 of them- 12 as class C RF power amps, plate modulated by 8 more!) in the experimental transmitter built by RCA for WLW, when they were running under special authorization at 500kW output. A great page about the station with a lot of pictures:

http://hawkins.pair.com/wlw.shtml

A good picture of an 862 tube:

http://radioheaven.homestead.com/RCA862.html

The RCA datasheet for the 862:

http://tubedata.tubes.se/sheets/049/8/862A.pdf


The other early "superpower" tube was the Western Electric 320A, which was developed for Mexican "Border Blaster" station XERA. Only 9 were ever made, 8 for the XERA transmitter, and one spare. Some neat pictures and info:

http://www.oldradio.com/archives/hardware/WE320A.htm

http://hawkins.pair.com/mexblast.shtml


Of course, both of these "beastatrons" were soon eclipsed in terms of raw power. I believe the title of "most powerful tube" is still held by the Eimac 8974 tetrode, used in megawatt class shortwave transmitters and particle accelerators:

http://www.cpii.com/docs/datasheets/81/8974.pdf

That guy takes nearly 10 kW just to heat the filaments! 22.5kV on the plate at 125 *AMPERES* plate current for a shade over 2 MEGAwatts of RF output in class C.