Sec. 73.1692  Broadcast station construction near or installation on an AM broadcast tower.

    Where a broadcast licensee or permittee proposes to mount a 

broadcast antenna on an AM station tower, or where construction is 

proposed within 0.8 km of an AM nondirectional tower or within 3.2 km of 

an AM directional station, the broadcast licensee or permittee is 

responsible for ensuring that

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the construction does not adversely affect the AM station, as follows:

	 (a) Installations on an AM nondirectional tower. During installation 

of the broadcast antenna and related equipment, the AM station shall 

determine operating power by the indirect method (see Sec. 73.51). Upon 

the completion of the installation, antenna impedance measurements on 

the AM antenna shall be made, and, prior to or simultaneously with the 

filing of the license application covering the broadcast station 

installation, an application on FCC Form 302-AM (including a tower 

sketch of the installation) shall be filed with the Commission for the 

AM station to return to direct power measurement.

	(b) Installations on an AM directional array. Prior to commencing 

construction, the broadcast permittee or licensee shall notify the AM 

station so that, if necessary, the AM station may determine operating 

power by the indirect method (see Sec. 73.51) and request special 

temporary authority pursuant to Sec. 73.1635 to operate with parameters 

at variance in order to maintain monitoring point field strengths within 

authorized limits. Both prior to the commencement of construction and 

upon completion of construction, a partial proof of performance (as 

defined by Sec. 73.154) shall be conducted to establish that the AM 

array has not been adversely affected. Prior to or simultaneously with 

filing of the license application to cover the broadcast station 

construction, the results of the partial proof of performance shall be 

filed with the Commission on Form 302-AM.

	(c) Tower erections or modifications within 0.8 km of an AM    

nondirectional tower. Prior to commencing the construction of tower 

modifications, or the erection of a new tower, within 0.8 km of an AM 

nondirectional tower, the broadcast permittee or licensee is required to 

notify the AM station so that the AM station may commence determining 

operating power by the indirect method (see Sec. 73.51). The broadcast 

licensee or permittee shall be responsible for the installation and 

continued maintenance of detuning apparatus necessary to prevent adverse 

effects on the radiation pattern of the AM station. Both prior to 

construction of the tower modifications and upon completion of 

construction, antenna impedance measurements of the AM station shall be 

made. In addition, sufficient field strength measurements taken at a 

minimum of 10 locations along each of 8 equally spaced radials, shall be 

made to establish that the AM radiation pattern is essentially 

omnidirectional. Prior or simultaneously with the filing of the 

application for license to cover this permit, the results of the 

impedance measurements and the field strength measurements shall be 

filed with the Commission on FCC Form 302-AM for the AM station to 

return to the direct method of power determination.

	(d) Tower erections or modifications within 3.2 km of an AM    

directional station. Prior to commencing construction of tower 

modifications, or the erection of a new tower structure, within 3.2 km 

of an AM directional array, the broadcast permittee or licensee shall 

notify the AM station so that, if necessary, the AM station may 

determine operating power by the indirect method (see Sec. 73.51) and 

request special temporary authority pursuant to Sec. 73.1635 to operate 

with parameters at variance in order to maintain monitoring point field 

strengths within authorized limits. The broadcast licensee or permittee 

shall be responsible for the installation and continued maintenance of 

detuning apparatus necessary to prevent adverse effects upon the 

radiation pattern of the AM station. Both prior to the commencement of 

construction and upon completion of construction, a partial proof of 

performance (as defined by Sec. 73.154) shall be conducted to establish 

that the AM array has not been adversely affected. Prior to or 

simultaneously with filing of the license application to cover the 

broadcast station construction, the results of the partial proof of 

performance shall be filed with the Commission on Form 302-AM.

[62 FR 51062, Sept. 30, 1997