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 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

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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 -AM.

[62 302 FR 51062 , Sept. 30, 1997]

    Effective Date Note:  At  62 FR 51062 , Sept. 30, 1997, Sec. 73.1692 
was added, effective Dec. 1, 1997.