Model 631 Vic-Tic
Radiation Survey Meter
Victoreen Model 631 "Vic-Tic"
The "Vic-Tic" is a commercial model radiation survey meter manufactured in the mid to late 1950's.
Manufactured by The Victoreen Instrument Company in Cleveland Ohio, the retail price on this unit was
$125.00 in 1955, which was a major expense at a time when the average weekly wage was $78.12.
This particular unit came to me with the optional external probe, original box and the
check source, no manual or carry strap was included. There is no serial number on this unit.
Range of 0 - 100,000 Counts Per Minute over 4 scales.
The case and top are made of gold colored anodized aluminum , the aluminum handle and bottom
plate are natural color.
Dimensions: 7" Long x 3¾" Wide x 7" Tall (including handle)
Front & Rear End Views
The front has a opening for the optional external probe, a chrome plated cover goes over the hole when the
probe is not used. The rear has the internal mounted speaker.
There are no provisions for a headset for this model, only the speaker is used.
Left & Right Inside Views
This is a "hybrid" circuit which has vacuum tubes and a Raytheon CK722 transistor to amplify the audio
circuitry. The CK 722 shows a date code of 4-45, which is the 45th week of 1954. This is a very early
use of a transistor in a consumer product as the transistor was invented only 7 years earlier.
Front & Rear Inside Views
These views show the ¼" phone type jack for the optional external 1B85 probe, and the germanium
junction transistor amplified speaker.
Inside Bottom View
This view is with the probe-holding bottom cover removed and the batteries taken out.
This model uses two batteries, one Eveready No. 720 1½ volt battery and one Eveready No. 477
67½ volt battery.
Inside Bottom View
This view shows the batteries installed and the bottom plate with the 1B85 Geiger-Müller probe
mounted to it.
Bottom Plate & Check Source
The bottom plate of the "Vic-Tic" holds the Victoreen 1B85 Geiger-Müller probe.
The check source is laminated with plastic, and is listed on the box as " Radiation-Equivalent-Ore source".
Optional External Probe
The external probe was an option with this model and plugs into the front of the survey meter.
The probe is mounted on a 4 foot cable with a ¼" phone type jack. The Geiger-Müller probe is another
Victoreen 1B85 thin wall aluminum probe.
Close-Up of Meter Face & Controls
The meter is marked only in counts per minute. The controls are the scale selector switch and the
internal speaker volume control.
Bottom View
This shows the plastic covering over the 1B85 Geiger-Müller tube mounted to the inside of
the bottom plate.
