47 CFR 73.182 - Engineering standards of allocation.
|Class of station||Effective field (at 1 km)|
|Note (1): When a directional antenna is employed, the radiated signal of a broadcasting station will vary in strength in different directions, possibly being greater than the above values in certain directions and less in other directions depending upon the design and adjustment of the directional antenna system. To determine the interference in any direction, the measured or calculated radiated field (unattenuated field strength at 1 kilometer from the array) must be used in conjunction with the appropriate propagation curves. (See § 73.185 for further discussion and solution of a typical directional antenna case.)|
|Note (2): For Class B stations in Alaska, Hawaii, Puerto Rico and the U.S. Virgin Islands, 241 mV/m shall be used.|
|All Class A (except Alaskan)||362 mV/m.|
|Class A (Alaskan), B and D||282 mV/m.|
|Class C||241 mV/m.|
|Class of station||Class of channel used||Signal strength contour of area protected from objectionable interference 1(µV/m)||Permissible interfering signal (µV/m)|
|Day 2||Night||Day 2||Night 3|
|1 When a station is already limited by interference from other stations to a contour of higher value than that normally protected for its class, this higher value contour shall be the established protection standard for such station. Changes proposed by Class A and B stations shall be required to comply with the following restrictions. Those interferers that contribute to another station's RSS using the 50% exclusion method are required to either reduce their contributions to that RSS by 10%, or to a level at which their contributions no longer enter into the 50% RSS value, whichever is the lesser amount of reduction. Those interferers that contribute to a station's RSS using the 25% exclusion method but do not contribute to that station's RSS using the 50% exclusion method may make changes not to exceed their present contribution. Interferers not included in a station's RSS using the 25% exclusion method are permitted to increase radiation as long as the 25% exclusion threshold is not equalled or exceeded. In no case will a reduction be required that would result in a contributing value that is below the pertinent value specified in the table. This note does not apply to Class C stations; or to the protection of Class A stations which are normally protected on a single signal, non-RSS basis.|
|3 Skywave field strength for 10 percent or more of the time.|
|4 During nighttime hours, Class C stations in the contiguous 48 States may treat all Class B stations assigned to 1230, 1240, 1340, 1400, 1450 and 1490 kHz in Alaska, Hawaii, Puerto Rico and the U.S. Virgin Islands as if they were Class C stations.|
|Note: SC=Same channel; AC=Adjacent channel; SW=Skywave; GW=Groundwave|
|A||Clear||SC 100||SC 500 50% SW||SC 5||SC 25|
|AC 500||AC 500 GW||AC 250||AC 250|
|A (Alaskan)||......do||SC 100||SC 100 50% SW||SC 5||SC 5|
|AC 500||AC 500 GW||AC 250||AC 250|
|C||Local||500||No presc.4||SC25||Not presc.|
|D||Clear||500||Not presc||SC 25||Not presc.|
|Frequency separation of desired to undesired signals (kHz)||Desired Groundwave to:||Desired 50% Skywave to Undesired 10% Skywave (dB)|
|Undesired groundwave (dB)||Undesired 10% Skywave (dB)|
Title 47 published on 2014-10-01.
The following are only the Rules published in the Federal Register after the published date of Title 47.
For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.
Title 47 published on 2014-10-01
The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 47 CFR Part 73 after this date.