5 Oct
2005
5 Oct
'05
6:44 a.m.
>>>> "Tony" == Tony Duell <ard
at p850ug1.demon.co.uk> writes:
> > I am told, BTW, that several radar operates
in planes in the
> last war > were killed when the plane had a heavy landing, the
> radar display CRT > imploded, and they were litterally shot in the
> face by bits of the > electron gun.
>
> Not something I'd heard before - but I can certainly believe that;
> such displays tend to be pretty large in diameter and of course
> are flat-faced so must be naturally pretty weak toward the centre
> of the face.
Tony> Actually, no. The standard radar CRT over here at that time was
Tony> the VCR97. That's a 6" diaameter thing with a fairly convex
Tony> screen. (Incidentally, VCR stood for Valve, Cathode Ray, or so
Tony> I am told).
But larger flat face radar tubes appeared in the 1960s if not
earlier. The CDC 6000 series console (DD60) uses a pair of radar
tubes, with electrostatic deflection. I'm not sure exactly how big
they are, but certainly not less than 12 inches. They were probably
at least 2 feet long. Deflection voltage is around 2 kV, supplied by
an amplifier chain ending in a 3CX100A5 microwave transmitter tube.
The radar tubes used until maybe 5 years ago at US air traffic control
centers were at least that big, possibly bigger, and also flat.
paul