47 CFR 73.155: Directional antenna performance recertification.

A station licensed with a directional antenna pattern pursuant to a proof of performance using moment method modeling and internal array parameters as described in § 73.151(c) shall recertify the performance of the antenna monitor sampling system only in the case of repair to or replacement of affected system components, and then only as to the repaired or replaced system components. Any recertification of repaired or replaced system components shall be performed in the same manner as an original certification of the affected system components under § 73.151(c)(2)(i) of this part. The results of the recertification measurements shall be retained in the station's public inspection file.