Signedraised lettering on front panel: Radar-Eye
plate on front panel, top center: U.S. PATENET RE 25,100 / PINKERTON / ELECTRO-SECURITY CORP. / WEBSTER, MASS. U.S.A. / FOREIGN PATENTS PENDING
plate on front panel, top right: PINKERTON / (logo) / SECURITY SERVICE
plate inside lid: RADAR-EYE / U.S. PATENT NUMBER RE 25,100 / MODEL A7-5 SERIAL 3391 / VOLTAGE 115 VAC 60 ~ AMP 50 / PINKERTON ELECTRO-SECURITY CORP. / (logo) / WEBSTER, MASS. U.S.A.
Inscribedon small round sticker over keyhole: O.K.
FunctionThis type of device used a generated RF field for detecting intrusion. When this field was disrupted this would cause the alarm to sound.
The system works using the same principle as police highway radars: when radio waves bounce off moving objects, their frequency is slightly altered. When the device detects a change in frequency, it sounds the alarm.
Historical AttributesUsed by D.P. Wheatland in the Pingree Farm House 1966 to 1967, removed in 1982 to Radio Shed. May have been used for intrusion detection inside Radio Shed as well.
Primary SourcesThis device is described in Popular Mechanics, December 1967, pp.86-89. Available in Google Books here.
For an earlier description of a smaller version of this device, see Popular Mechanics, September 1963, p. 191. Available in Google Books here.
ProvenanceDavid Wheatland.