Jordan Model AGB-10KG-SR "Radgun" (1957 - 1965)
Manufactured by Jordan Electronic Mfg. Co. Inc. of Pasadena California, the Radgun was a unique looking wide range ionization survey meter. It had a pistol grip, a gold cylindrical body with a circular logarithmic scale on one end, and it came in three versions: AGB-1G-SR, AGB-10G-SR, and the AGB-10KG-SR. The SR at the end of the model number referred to the built-in Sr-90 check source. The GB at the beginning of the number, referred to the fact that they were sensitive to gamma and beta radiation. The only difference between the three models was their ranges of operation.
The predecessors to the Radgun, the AGB-1-SR, AGB-10-SR and AGB-10K-SR, had a shorter body, a chrome metal handle, and a separate 5.75” x 3.5” x 2.25” control unit. They were produced at least as early as 1954.
most unique thing about the Radgun was not its appearance, but its use of
the Neher-White ionization chamber. This chamber had several interesting
features: the chamber current drove the meter directly in a logarithmic mode
without any type of amplification; the electrometer tube was sealed inside
the chamber itself; the chamber was of all steel construction; and it was
filled with argon at high pressure (Neher’s principal field of study was
cosmic radiation, a field in which the use of high pressure ion chambers was
commonplace). The steel construction provided
considerable strength, but it also created an over-response at low energies
that was compensated for by the use of a lead filter.
If desired, the chamber could be detached and connected to a six-foot extension probe or a 25” cable.
Detector: high pressure (10 atmospheres), argon filled detachable ion chamber with a 20 mg/cm2 window.
Ranges: Log scale,
4.5” diameter and 12.75” long
Batteries: three 1.34 volt, one 5 volt, and three 30 volt batteries
Donated by Ron Kathren
Nucleonics November 1957 p 198.
Nucleonics January 1958 p 36.
brochure “Survey Meters, Dosimeters”, Form 3038-61, 1961;
Manual for Jordan Model AGB-10G-SR - the circuit diagram for the Radgun
carries two dates
Copyright 1999, Oak Ridge Associated Universities