A relic from the Cold War nuclear jitter, a Geiger Counter's manualRadiac Set AN/PDR-27F

by Jim Cline

Background: Circa 1980 I bought an old surplus Geiger Counter, made in 1954. Although the over-hundred-volt batteries for it were no longer available, I was able to create a virtual battery for the high voltage for the vacuum-tube instrument by stacking 15 of the conventional 9 volt batteries together, and was able to use the instrument to measure the radiation in my environment. There seemed to be a high energy source of some kind occasionally toasting my immediate environment, source or type unknown. Unfortunately I was not able to have the Geiger Counter running at any time and place when the "energy beam" was toasting things including parts of me, so was not able to confirm its nature re nuclear energy sourcing or perhaps misuse of a structural inspection X-ray generator, or high intensity microwave beam.

I recall using a similar instrument during my training to be a Radiation Monitor back in the mid-1960's. The training taught how to use the instrument to locate areas of lesser radiation in case of a nuclear blast nearby that one had happened to survive. Part of training graduation was for all trainees to share in eating from a can of beans that had been subjected to severe radiation from our radiation sample used in the training course, to show we were confident of the edibility of contents of sealed canned goods, an important bit of knowledge in case things have been smashed all around your area. If I can find my copy of handouts of how to build a fallout shelter depending on circumstance material and time availability, I will add it to these Historical Items pages. People nowadays do not usually have the sense of any moment being bombed by a nuclear weapon, and how to deal with it rationally to optimize long term survivability of self and others.

The instrument is still in my possession (as of April 25, 2008; the world has gotten weird again, my belongings keep disappearing, so who knows of tomorrow here) although the old GC instrument is not currently working. Perhaps its manual's pages would be of historical interest to others, however; and so below are some representative pages from the manual and other related written material. Enjoy.

(Ref: http://www.escalatorhi.com/JimDabblingH/gcmid1960s.html )

Cover of the manual for the "Radiac Set AN/PDR-27F" Geiger Counter.

First page of the Table of Contents

Contents of the instrument's waterproof case.

Color codes used on parts in the instrument.

Original calibration card, showing calibration in 1966.

Overlay of my personal first calibration note, on top of an addendum sheet of the type used back then for a field change, T-2 to NAVSHIPS 91856, dated 29 March 1954. And my calibration overlay shows that my glowing-hands night-readable wristwatch, which I had worn day and night for decades, was producing between 1.5 to 3 mr/hr.