On Mon, 4 Jan 2010, Scott Dorsey wrote:

Barry wrote:
I know this is a very long shot, but I wondered if anyone has a
geiger-muller tube lurking anywhere?
Perhaps you may know of a supplier or have an old geiger counter that you
may wish to dispose of?


Not sure if you've seen these but...

http://www.goldmine-elec-products.co...?number=G17365

The thing about these is that the glass is designed to block lower energy
radiation. Still, if you want to detect background gamma radiation, it's
not bad. It's probably okay for beta radiation too although you don't know
until you test it.

The market is glutted with Victoreen survey meters. Millions of them were
made for the civil defense folks in the fifties and sixties, and they are
all on the surplus market. They also don't respond well to lower energy
particles, and the scale calibration is useless because the integrator stage
is intended for use in very high radiation environments, but they are very
cheap.

But there was also a need for geiger counters so you could go out and
prospect for uranium. I hadn't given it a lot of thought, until a few
years ago when I found a "magazine" about how to prospect for uranium.
I guess it was published by Fawcett, from the fifties, when it was common
to issue single issue magazines that would be books if they were published
more formally. I have no idea how common the "hobby" was, or how many
geiger counters it sold, but it did seem a big concept for a while.
Robert Heinlein even has some bad guys in one of his juvenile novels
prospecting for uranium on the moon.

There have been solid-state replacements for geiger tubes in recent
decades, but at the moment I can't think of what. Some projects used
existing components that reacted to radiation, but I seem to recall there
were solid-state devices that came along.

Michael VE2BVW