Sec. 73.62  Directional antenna system tolerances.

    (a) Each AM station operating a directional antenna must maintain 
the indicated relative amplitudes of the antenna base currents and 
antenna monitor currents within 5% of the values specified therein. 
Directional antenna relativephase currents must be maintained to within 
&177;3 deg. of the values specified on the instrument of 
authorization, unless other tolerances are specified therein.
    (b) Whenever the operating parameters of a directional antenna 
cannot be maintained within the tolerances specified in paragraph (a) of 
this section, the following procedures will apply:
    (1) The licensee shall measure and log every monitoring point at 
least once for each mode of directional operation. Subsequent variations 
in operating parameters will require the remeasuring and logging of 
every monitoring point to assure that the authorized monitoring point 
limits are not being exceeded.
    (2) Provided each monitoring point is within its specified limit, 
operation may continue for a period up to 30 days before a request for 
Special Temporary Authority (STA) must be filed, pursuant to paragraph 
(b)(4) of this section,

[[Page 26]]

to operate with parameters at variance from the provisions of paragraph 
(a) of this section.
    (3) If any monitoring point exceeds its specified limit, the 
licensee must either terminate operation within 3 hours or reduce power 
in accordance with the applicable provisions of Sec. 73.1350(d), in 
order to eliminate any possibility of interference or excessive 
radiation in any direction.
    (4) If operation pursuant to paragraph (b)(3) of this section is 
necessary, or before the 30 day period specified in paragraph (b)(2) of 
this section expires, the licensee must request a Special Temporary 
Authority (STA) in accordance with Sec. 73.1635 to continue operation 
with parameters at variance and/or with reduced power along with a 
statement certifying that all monitoring points will be continuously 
maintained within their specified limits.
    (5) The licensee will be permitted 24 hours to accomplish the 
actions specified in paragraph (b)(1) of this section; provided that, 
the date and time of the failure to maintain proper operating parameters 
has been recorded in the station log.
    (c) In any other situation in which it might reasonably be 
anticipated that the operating parameters might vary out of tolerance 
(such as planned array repairs or adjustment and proofing procedures), 
the licensee shall, before such activity is undertaken, obtain an STA in 
accordance with Sec. 73.1635 in order to operate with parameters at 
variance and/or with reduced power as required to maintain all 
monitoring points within their specified limits.

[ 50 FR 30946 , July 31, 1985, as amended at  60 FR 55480 , Nov. 1, 1995]