Portable Airplane Detector Worn by "Spotter"

Item

Civilian and military airplane “spotters” can convert themselves into mobile listening stations with the aid of a portable plane detector designed for use where more elaborate units are not available. Sound of an approaching plane is picked up by a microphone centered in a parabolic concentrator worn as a headpiece. When a low-pitched sound is heard in the earphones, the listener turns his body until the sound is at its loudest, in which position he will be facing its source and can focus his binoculars swiftly and accurately on the aircraft for identification. The amplifier, batteries and accessories are housed in a carrying case slung over the watcher’s shoulder. Three miniature tubes are used in the amplifier. Filters eliminate noises other than those created by airplanes. Volume can be controlled to suit the operator.

Title (Dublin Core)
Portable Airplane Detector Worn by "Spotter"
Subject (Dublin Core)
en
en
Article Title and/or Image Caption (Dublin Core)
Portable Airplane Detector Worn by "Spotter"
Language (Dublin Core)
Eng
Temporal Coverage (Dublin Core)
World War II
Date Issued (Dublin Core)
1942-06
Is Part Of (Dublin Core)
Popular Mechanics, vol. 77, n. 6, 1942
pages (Bibliographic Ontology)
45
Rights (Dublin Core)
Public domain
Source (Dublin Core)
Google books
Archived by (Dublin Core)
Enrico Saonara