FCC 90.539 Revised as of September 29, 2014
Goto Year:2013 |
§ 90.539 Frequency stability.
Transmitters designed to operate in 769-775 MHz and 799-805 MHz
frequency bands must meet the frequency stability requirements in this
(a) Mobile, portable and control transmitters must normally use
automatic frequency control (AFC) to lock on to the base station
(b) The frequency stability of base transmitters operating in the
narrowband segment must be 100 parts per billion or better.
(c) The frequency stability of mobile, portable, and control
transmitters operating in the narrowband segment must be 400 parts per
billion or better when AFC is locked to the base station. When AFC is
not locked to the base station, the frequency stability must be at
least 1.0 ppm for 6.25 kHz, 1.5 ppm for 12.5 kHz (2 channel aggregate),
and 2.5 ppm for 25 kHz (4 channel aggregate).
(d) The frequency stability of base transmitters operating in the
wideband segment must be 1 part per million or better.
(e) The frequency stability of mobile, portable and control
transmitters operating in the wideband segment must be 1.25 parts per
million or better when AFC is locked to a base station, and 5 parts per
million or better when AFC is not locked.
[ 63 FR 58651 , Nov. 2, 1998, as amended at 65 FR 53646 , Sept. 5, 2000;
72 FR 48861 , Aug. 24, 2007]
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