Richard,

Randall & Boot's original magnetron used to be displayed in the
London, England, Science Museum. It was all by itself in a very
large, securely locked glass case. No magnet. I don't know whether it
is still there.

It lay there, all forlorn, hardly noticed, about the same
insignificant size as a small, half-size, rusty can of baked beans.

My sentiments lie with R and B, slaving away in the laboratory at
Birmingham University while the Luftwaffer rained down bombs and
incendiaries on the city. At the time, the top-secret goings-on were
unknown to me, and I spent my time in a corrugated-iron air raid
shelter in the back garden just a few miles down the road.

A few years later, having joined the RAF as a Radar technician, I had
the pleasure of holding a production model in one hand and the magnet
in the other. At the other end of the workshop bench a parabolic dish
rotated once every two seconds. It is not true that a 50 kW peak pulse
power at 3000 Mhz sterilises one's reproductive organs. I have
fathered 5 children.

It was left to the Japanese to populate the World's kitchens with
microwave ovens. Beyond the first, no magnetron has ever been made in
the industrial city of Birmingham, England. But they don't make many
motor cars there any more either.