47 CFR 90.539 - Frequency stability.

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§ 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 section.

(a) Mobile, portable and control transmitters must normally use automatic frequency control (AFC) to lock on to the base station signal.

(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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United States Code
Statutes at Large

Title 47 published on 2015-10-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 47 CFR Part 90 after this date.

  • 2015-11-25; vol. 80 # 227 - Wednesday, November 25, 2015
    1. 80 FR 73696 - Public Safety and Homeland Security Bureau Seeks Comment on FirstNet's Incumbent Relocation Proposal
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      FEDERAL COMMUNICATIONS COMMISSION
      Proposed rule.
      Comments are due on or before December 9, 2015.
      47 CFR Part 90