NCJ Number
92645
Date Published
1983
Length
44 pages
Annotation
This guide provides information on the choice of mobile radio equipment, addressing factors that law enforcement purchasers should consider, test results of selected equipment, tradeoffs in system and equipment performance, and Federal Communications Commission (FCC) regulations.
Abstract
Following a brief overview of FM mobile communication development, the booklet focuses on a system's technical aspects, explaining coverage by different frequency bands, manmade noise, and interference. It then describes two examples of tradeoffs that system designers might encounter: talking range versus interference and simplex versus duplex communications. The chapter on FCC regulatory aspects examines frequency allocation, acceptable transmitter equipment, and the petition by land-mobile radio service for additional radio frequency spectrum to relieve existing congestion and anticipated growth in mobile communications. Technical information is provided for the following equipment: mobile radios; antennas; power sources; microphones and speakers; and accessories such as repeaters, voting receiver systems, voice privacy systems, automatic vehicle location systems, and scanning receivers. Suggestions on service and safety cover maintenance through in-house, local contract, and factory services, maintenance costs, the danger of extended close exposure to high rf fields, detonating explosive mixtures, and other occupational hazards. The section on purchasing lists questions that agencies should answer before buying mobile communications equipment. Photographs, diagrams, 39 footnotes, and 22 references are supplied.