Re: [amsat-bb] Homemade Geiger Counter

[Brian <bmitton1@xxxxxxxxxxxxxx>]

Bob,

What I did, was to just buy one of these;
http://lndinc.com/gm/gmbg.htm

For a power supply, I used an inverter for a cold cathode
fluorescent lamp.  I got a filter / regulator circuit from
the 1972 ARRL handbook.
The output circuit is straight from the brochure.
The output from the GM tube goes to the IRQ pin of a PIC.
The trick here is not to pull up too hard.  The internal
"weak" pull up was too strong!

Good luck, and I hope we never need these.

Brian
N8NPA

Anthony Monteiro wrote:

 >> Hi Bob,
 >>
 >> How about this one using a neon bulb?
 >> http://www.elecdesign.com/Articles/Index.cfm?ArticleID=1634
 >> Tony AA2TX
 >>
 >> ---
 >> At 11:48 AM 7/27/2004 -0400, Robert Bruninga wrote:
 >>
 >
 >>>> As we approach armagedon, I thought it might
 >>>> be nice to have a Geiger counter.
 >>>>
 >>>> Which, if I recall is just an ionization chamber,
 >>>> a voltge charge and an audio amp.  Since Radio
 >>>> Shack does not have GeigerMueller tubes, do I
 >>>> remember correctly that you could even use
 >>>> a flourescent bulb for the ionization chamber?
 >>>>
 >>>> Just thought it would be nice to have something
 >>>> to detect high energy particles around the house
 >>>> or on a satellite, or feeding alerts onto APRS?
 >>>> (hence asking on both sigs)..
 >>>>
 >>>> Bob
 >>>> ----
----
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