NCJ Number
106788
Date Published
1987
Length
17 pages
Annotation
This equipment standard for fixed and base-station FM transmitters, developed by the Law Enforcement Standards Laboratory, specifies performance and other requirements for meeting the needs of criminal justice agencies for high quality performance.
Abstract
In addition to covering minimum performance at environmental extremes, including humidity and temperature stability; audio modulation (AM), including audio harmonic distortion, FM hum and noise level, audio responses, and modulation limiting; and radio frequency characteristics such as output power, frequency stability, AM hum and noise level, and carrier attack time. Other standards consider electromagnetic compatibility characteristics relevant to conducted and radiated spurious transmissions and sideband spectrum. Test methods for these requirements and characteristics also are provided. The standards apply to transmitters without special subsystems such as selective signaling or voice privacy, or in which such subsystems are bypassed or disabled during testing for compliance with these standards. It covers Type I (25-50 MHz), II (150-174 MHz), III (400-512 MHz), and IV (806-866 MHz) transmitters. 13 figures, 2 references, and 6-item bibliography.