14 Jul
2007
14 Jul
'07
1:35 a.m.
On Thu, 12 Jul 2007, Tony Duell wrote:
IIRC, the very common 2D21 (EN91 in Europe) is a hot
cathode tetrode
xenon thyratron.
Most of the time they are called PL21, I think because most other "big"
thyratrons are PLxx, too, even if this is syntactically incorrect
(they're not 300mA series heated power pentodes). From the several dozens
I have I don't have one that's labelled EN91.
Christian