NCJ Number
80420
Date Published
1981
Length
45 pages
Annotation
Results of tests to determine whether 26 personal FM radio transceivers meet minimum performance requirements for use in law enforcement are reported.
Abstract
The 26 transceivers represented basic models produced by 8 separate manufacturers. Transceiver performance was tested under ambient temperature conditions, conditions of high and low operating voltages, vibration, and extremes of humidity and temperature. Results indicate that all of the transceivers met sensitivity requirements under ambient temperature conditions, but only 72 percent met sensitivity requirements under extremes of temperature and humidity. With regard to selectivity (i.e., capability of differentiating between the desired signal and other signals), only six transceivers complied with all four of the selectivity requirements of the standard (usable band width, adjacent channel selectivity, spurious response attenuation, and intermodulation). The majority met all of the requirements for receiver squelch circuit function to prevent a receiver from producing output power in the absence of a radio frequency input signal. Nine of the transceivers equaled the standard for receiver audio frequency (levels of audio output power, audio distortion, audio frequency response, and audio hum and noise). Twenty-four of the transceivers maintained carrier output power within allowed tolerances, and only one transceiver did not meet the carrier frequency tolerance. Taken collectively, transceiver performance was least satisfactory in the area of transmitter audio frequency modulation (audio frequency harmonic distortion, FM hum and noise, audio frequency response, frequency deviation, and modulation limiting). Electromagnetic compatibility, antenna effectiveness, and battery life were also tested. A summary page for each transceiver contains a brief description of the transceiver, the manufacturer's published specifications, and the performance requirements of the standard for tests under standard conditions. A bibliography and a list of manufacturers are supplied.