(b)Radio receiving installations. Protection for Table Mountain Radio Receiving Zone, Boulder County, Colorado: Applicants for a station authorization to operate in the vicinity of Boulder County, Colorado under this Part are advised to give due consideration, prior to filing applications, to the need to protect the Table Mountain Radio Receiving Zone from harmful interference. These are the research laboratories of the Department of Commerce, Boulder County, Colorado. To prevent degradation of the present ambient radio signal level at the site, the Department of Commerce seeks to ensure that the field strengths of any radiated signals (excluding reflected signals) received on this 1800 acre site (within the area bounded by 40°09'10" N Latitude on the north, 105°13'31" W Longitude on the east, 40°07'05" N Latitude on the south, and 105°15'13" W Longitude on the west) resulting from new assignments (other than mobile stations) or from the modification of relocation of existing facilities do not exceed the following values: Frequency range | Field strength in authorized bandwidth of service (mV/m) | Power flux density in authorized bandwidth of service (dBW/m2)1 |
Below 540 kHz | 10 | -65.8 |
540 to 1700 kHz | 20 | -59.8 |
1.7 to 470 MHz | 10 | 2-65.8 |
470 to 890 MHz | 30 | 2-56.2 |
Above 890 MHz | 1 | 2-85.8 |
1 Equivalent values of power flux density are calculated assuming free space characteristic impedance of 376.7 = 120 ohms.
2 Space stations shall conform to the power flux density limits at the earth's surface specified in appropriate parts of the FCC rules, but in no case should exceed the above levels in any 4 kHz band for all angles of arrival.
(1) Advance consultation is recommended particularly for those applicants who have no reliable data which indicates whether the field strength or power flux density figures in the above table would be exceeded by their proposed radio facilities (except mobile stations). In such instances, the following is a suggested guide for determining whether coordination is recommended:(i) All stations within 2.4 km (1.5 statute miles);(ii) Stations within 4.8 km (3 statute miles) with 50 watts or more effective radiated power (ERP) in the primary plane polarization in the azimuthal direction of the Table Mountain Radio Receiving Zone;(iii) Stations within 16 km (10 statute miles) with 1 kW or more ERP in the primary plane of polarization in the azimuthal direction of Table Mountain Receiving Zone;(iv) Stations within 80 km (50 statute miles) with 25 kW or more ERP in the primary plane polarization in the azimuthal direction of Table Mountain Receiving Zone.(2) Applicants concerned are urged to communicate with the Radio Frequency Management Coordinator, Institute for Telecommunication Sciences, 325 Broadway, Boulder, CO 80305; telephone (303) 497-4220, email frequencymanager@ntia.gov, in advance of filing their applications with the Commission.(3) The Commission will not screen applications to determine whether advance consultation has taken place. However, applicants are advised that such consultation can avoid objectimns from the Department of Commerce or proceedings to modify any authorization which may be granted which, in fact, delivers a signal at the site in excess of the field strength specified herein.