AM Power and Operational issues

AM Station Power

Class Present Maximum Proposed Region II US-Mexican US-Canadian
A 50 kW Day
50 kW Night
100 kW Day *
50 kW Night
 100 kW Day
50 kW Night
 100 kW Day
50 kW Night
 50 kW Day
50 kW Night
B 50 kW Day
50 kW Night
50 kW Day
50 kW Night
50 kW Day
50 kW Night
50 kW Day
50 kW Night
50 kW Day
50 kW Night
BEx band 10 kW Day
1 kW Night
50 kW Day **
50 kW Night ***
50 kW Day
50 kW Night
10 kW Day
1 kW Night
10 kW Day
1 kW Night
C 1 kW Day
1 kW Night
1 kW Day
1 kW Night
1 kW Day
1 kW Night
1 kW Day
1 kW Night
1 kW Day
1 kW Night
D 50 kW Day
0.249 kW Night
50 kW Day
1 kW Night
 N/S N/S N/S

Note: * 0.025 mV/m contour shall not extend beyond Canadian border further than produced by 440 * Sqrt(P) mV/m at same location, where P is the

power in kiloWatts specified in the appropriate US-Canadian Agreement.

**  o.o25 mV/m contour shall not extend beyond the Canadian or Mexican border further than that produced by 980 mV/m at same location.

*** Night interfering signal shall not produce more than 0.083 mV/m 10% SWF on any Canadian or Mexican Allocation.

Redesignation of Class C Stations

Class C stations operating on 1230, 1240, 1340, 1400, 1450 or 1490 kHz may be re-designated as class D on its present channel upon application, including eligibility for greater day power, and transitional power authorizations, and utilizing its presently authorized night antenna and power.

Antenna Efficiency

It is proposed that antenna efficiency be removed as a licensing requirement.  There are several innovative designs for physically small antennas which may not currently be used because either they intrinsically develop less than the minimum field intensity specified in FCC rule 73.189, or because the addition of resistive loading to achieve an adequate bandwidth decreases the net efficiency below the presently required value.  Zoning, environmental and aviation limitations have severely limited the ability of AM stations to be relocated upon losing a transmitter site.  This has in several cases caused the loss of important AM service.

When a non-standard antenna is proposed,  the radiation efficiency should be established either by the methods of FCC rules 73.186, or by the specifications of the antenna manufacturer.   Antenna manufacturers must establish the performance of AM Antennas on sample antennas and maintain records of the measured antenna efficiency.

Synchronous Networks

Although there has been mixed success in implementing synchronous networks in the United States, operations in other countries with more than two members of the network, and using different synchronizing methods have had reasonably effective results.  Experimentation leading to permanent authorizations should be encouraged, particularly in the context of AM HD radio and other technologies.

Alternate Digital Transmission Systems

Regulations should be modified to permit medium wave HD Radio full digital operation under MA-3 and MA-4 modes, particularly in the expanded band.  Experimentation and developmental operation with DRM30 and other modulation systems should be encouraged.  It has been shown that hybrid AM HD operation causes significant in-market and skywave adjacent channel interference to other stations, and finding alternatives such as transition to HD Radio  MA-3, MA4 and Digital Radio Mondiale are needed if AM radio will have a successful transition to digital broadcasting.

Migration to Expanded Band

Class C, Class D and Class B stations should be given the opportunity to “flash cut” to the expanded band.  The FCC could open a window and accept minor change applications to move to the expanded band.  All correct and non mutually exclusive applications can be granted, then the FCC could open a window for coordinated technical modifications.  Those applications that are then non -mutually exclusive would then be granted.  Remaining mutual exclusivity would be resolved by improvement in population and service for each mutually exclusive proposal.  The present service area would be analyzed and decreased by existing received interference.  This area would be compared with the proposed service (as reduced by any interference received).   Coverage credit would also be issued for additional service area gained if existing interference to other stations was eliminated.   A credit could be assigned for those applications that propose to operate digital only.  The station with the greater gain in service would be issued an authorization and the other(s) dismissed.

After this window has been processed, the FCC could then open a window for new digital only and additional “flash cut” modifications to digital only stations in the expanded band,

In the case that a Class D AM station seeks to “flash Cut” to the expanded band but it is impractical to operate with 1000 Watts at night while protecting domestic stations and/or meet international requirements,  or cannot maintain an adequate night service area while avoiding interference to other expanded band stations, the Class D station should be permitted to migrate as a class D station.

Local Media Ownership and FCC Fees

AM Radio stations produce only one program channel, FM stations regularly produce two or more  channels using HD radio.  AM daytime and Class C stations have no protected night service, so they have effective service hours of operation of only one half day each day.   The programs of both AM and FM stations are an equivalent audio service in the community. As such, AM radio stations do not have the same weight toward local radio ownership dominance  It is proposed that AM and FM stations be counted for local ownership considerations as a single category (AM and FM stations added toward a single total)  Class A and B stations should count as one half of an FM station and Class C and D stations should count as one fourth of an FM station.

With respect to FCC regulatory fees, AM stations should have fees one half of that of equivalent coverage FM stations since AM stations have fewer channels of programming, and Class C and D stations have fees of one quarter of the equivalent coverage FM station since they have only half the hours of protected service.

 

 


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