47 C.F.R. § 87.71 Frequency measurements.
Title 47 - Telecommunication
A licensed operator must measure the operating frequencies of all land-based transmitters at the following times: (a) When the transmitter is originally installed; (b) When any change or adjustment is made in the transmitter which may affect an operating frequency; or (c) When an operating frequency has shifted beyond tolerance.
Title 47: Telecommunication
PART 87—AVIATION SERVICES
Subpart C—Operating Requirements and Procedures
Operating Requirements
§ 87.71 Frequency measurements.
