Hi Darby,
Firstly I thought your suggestion very strange as the only Klystron's I have come across have been in-built/integral within a metal cavity for good frequency stability, as any external sources could alter the frequency greatly if mounted in only a glass tube.
What I mean is externally- they don't look like the classic glass Vacuum tube- more like a small die-cast metal box, normally painted black.
Well, within a few seconds of a Google search I nailed it down and your friend seems to be correct!
It very much appears to be a CV35 WWII reflex klystron the info on it and it's equivalants are here
CV35
It is a low powered device (and to put that in to a total perspective, only 300 milliwatts, that is 0.3 watts of power, compared to some very high power units made by Mullard that produce over 50kW - that is 50,000 watts of output power! These mega power units are usually used by High power TV stations.
I have been in the BBC site at Crystal Palace (The main London TV mast) where those Klystron beasts used to (and probably still do?!) provide the main Terrestrial TV signals all pumped up a 1,000 foot tower approx!!!
I recall they looked very much like smallish/standard under kitchen worktop domestic fridges- normally white!
Now that is engineering!
(Info. on the CV35 etc. taken from Google):
Designed by EMI in 1941. Manufactured by EMI and, after initial assembly by the Radiophysics division of the Australian Council for Scientific Research, by Australian Standard Telephones Pty in New South Wales from 1942.
Factory installed external cavity; 2970 to 3095MHz tuning. 100mW minimum output power.
The geometry of this very early klystron made necessary the use of a quite high cavity voltage, 1 to 1.5kV, a severe limitation in airborne use. It wouldn't supply any more than 300 mW it seems, and was very useful for Radar monitors I would guess.
I must confess, I personally had not come across an "open glass tube" type such as this in my travels- but, then again- I have never looked inside any WWII radar gear!
The nearest I had seen were Nuvistors (Miniature, normally metal enclosed) Valves/Tubes or Acorn valves used in VHF/UHF test gear normally.
You certainly are never too old to learn
Very interesting-thanks!
Dave R
..and sincere apologies to those of you that find this tecchie stuff boring- sorry!
