Within certain areas where our amateur service is regulated by the FCC, it is necessary for radiation to be restricted so as to minimize possible impact on the operations of radio astronomy or other facilities that are highly sensitive to interference.  The following is a summary of those affected areas.  

Interference Office

National Radio Astronomy Observatory

P.O. Box 2, Green Bank, WV 24944. 

 

   The notification must include the geographical coordinates of the antenna, antenna ground elevation above mean sea level (AMSL), antenna center of radiation above ground level (AGL), antenna directivity, proposed frequency, type of emission, and transmitter power.  If an objection to the proposed operation is received by the FCC from the National Radio Astronomy Observatory for itself or on behalf of the Naval Research Laboratory at Sugar Grove, Pendleton County, WV, within 20 days from the date of notification, the FCC will take whatever action is deemed appropriate.

Line A begins at Aberdeen, WA, running by great circle arc to the intersection of 48° N, 120° W, thence along parallel 48° N, to the intersection of 95° W, thence by great circle arc through the southernmost point of Duluth, MN, thence by great circle arc to 45° N, 85° W, thence southward along meridian 85° W, to its intersection with parallel 41° N, thence along parallel 41° N, to its intersection with meridian 82° W, thence by great circle arc through the southernmost point of Bangor, ME, thence by great circle arc through the southernmost point of Searsport, ME, at which point it terminates. 

   OTHER QUIET ZONES  There are seven other rules for quiet zones listed in Section 1.924.  They are:

   Table Mountain Radio Receiving Zone of the Research Laboratories located in Boulder County, Colorado.  Read Section 1.924(b).  The Department of Commerce seeks to ensure that the field strengths of any radiated signals (excluding reflected signals) received on this 1800 acre site resulting from new assignments (other than mobile stations) or from the modification or relocation of existing facilities do not exceed the values given in a table.  Advance consultation is recommended, particularly for applicants that have no reliable data to indicate whether the field strength or power flux density figures in the table would be exceeded by their proposed radio facilities.  Coordination is recommended for stations located within 1.5 miles of the Table Mountain Radio Receiving Zone; stations located within 3 miles transmitting with 50W or more ERP in the primary plane of polarization in the azimuthal direction of the Table Mountain Radio Receiving Zone; stations located with 10 miles transmitting with 1 kW or more ERP in the primary plane of polarization in the azimuthal direction of Table Mountain Radio Receiving Zone;  stations located within 50 miles transmitting with 25 kW or more ERP in the primary plane of polarization in the azimuthal direction of Table Mountain Receiving Zone.  Communicate with the Radio Frequency Manager, Department of Commerce, 325 Broadway, Boulder, CO 80305; Telephone: 303–497–4619, Fax: 303–497–6982, E-mail: frequencymanager@its.bldrdoc.gov.

   FCC protected field offices.  Read Section 1.924(c).  It is intended to minimize possible interference to FCC monitoring activities.  It says that applications for stations (except mobile stations) that could produce on any channel a direct wave fundamental field strength of greater than 10 mV/m (−65.8 dBW/m2 power flux density assuming a free space characteristic impedance of 120π Ω) in the authorized bandwidth at the protected field office may be examined to determine the potential for interference with monitoring activities. After consideration of the effects of the predicted field strength of the proposed station, including the cumulative effects of the signal from the proposed station with other ambient radio field strength levels at the protected field office, the FCC may add a condition restricting radiation toward the protected field office to the station authorization.

In the event that the calculated field strength exceeds 10 mV/m at the protected field office site, or if there is any question whether field strength levels might exceed that level, advance consultation with the FCC to discuss possible measures to avoid interference to monitoring activities should be considered. Prospective applicants may communicate with: Chief, Enforcement Bureau, Federal Communications Commission, Washington, DC 20554.

Advance consultation is recommended for applicants that have no reliable data to indicate whether the field strength or power flux density figure indicated would be exceeded by their proposed radio facilities. Coordination is recommended for stations located within 1.5 miles of the protected field office; within 3 miles with 50 W or more average ERP in the primary plane of polarization in the azimuthal direction of the protected field offices; within 10 miles with 1 kW or more average ERP in the primary plane of polarization in the azimuthal direction of the protected field office; within 50 miles with 25 kW or more average ERP in the primary plane of polarization in the azimuthal direction of the protected field office.

SO WHAT?  Note that Section 1.924  is worded in terms of applicants and licensees planning to construct and operate a new or modified station at a permanent fixed location.  Amateur stations are not required to have any such location and their licensees do not make application to the FCC for either a frequency assignment or a permanent fixed location for their stations.  They are authorized frequency bands by Section 97.301.  They are, moreover - with the exceptions noted above - authorized to transmit from anywhere the amateur service is regulated by the FCC, read Section 97.5, and on and over the high seas outside any area where the amateur service is regulated by any authority other than the FCC, read Section 97.301. 

A GOOD AMATEUR PRACTICE, therefore, is to know where these other quiet zones are located and to avoid transmissions being made by your amateur station from within those zones where the rules indicate they could have a possible impact on the operations of radio astronomy or other facilities that are highly sensitive to interference.  Read BE Informed No. 30 GEPS AND GAPS OTA26.  With the exception of the above mentioned automatically-controlled beacons, most amateur station transmissions can be characterized as short-term intermittent low to medium power communications.  As such, they should pose little or no threat to the quiet zones.  But it is best to check with the zone frequency coordinator or field office supervisor for assurance that your station’s transmissions are such as to minimize possible impact on the operations of radio astronomy or other facilities that are highly sensitive to interference. 

FREQUENTLY ASKED QUESTIONS

    Although you would not be filing said application, and you may not view your amateur station as being at a permanent fixed location, you should consider the standards as insight into what the FCC expects in the way of carrying out your obligation to protect the monitoring station.  It is unlikely that it expects you to carry a weapon and perform sentry duties.

   Q.  What is the difference in meaning between the terms advanced coordination as stated in Section 1.924(c)(v) and advanced consultation as stated in Section 1.924(c)(vi)?

   A.  Neither term is defined in Part 1.   So we must assume that the modifier advanced means some action the licensee performs before establishing a station.  Coordination must mean to notify the protected field office supervisor of your planned station location and pertinent transmitting parameters and receive assurance that there is no objection.  Consultation must mean to discuss the matter with the protected field office supervisor and implement any recommendations received.

   Q.  I have an Amateur Class license.  If I establish a home in the National Radio Quiet Zone, would I be allowed to have a ham station?

   A.  Yes, because you are also the holder of an FCC-issued station license grant.  Section 97.5 and Section 97.301 authorize your station to transmit from almost anywhere the amateur service is regulated by the FCC and on or over the high seas outside any area where the amateur service is regulated by any authority other than the FCC.  An amateur station located in the NRQZ should enjoy a very low level of ambient radio noise.  Transmitting, however, may be another matter.

   First, there is Section 97.203(e) which says:

   Before establishing an automatically controlled beacon in the NRQZ or before changing the transmitting frequency, transmitter power, antenna height or directivity, the station licensee must give written notification thereof to the Interference Office, National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944.

   While that may not be the type of amateur station you intend to establish, there is still the matter of Section 1.924(a).  It says the requirements of this paragraph are intended to minimize possible interference at the Observatories. 

   Applicants (not you) and licensees (you) planning to construct and operate a new or modified station at a permanent fixed location within the NRQZ  must notify the Director, National Radio Astronomy Observatory, Post Office Box No. 2, Green Bank, West Virginia 24944, in writing, of the technical details of the proposed operation. The notification must include the geographical coordinates of the antenna location, the antenna height, antenna directivity (if any), the channel, the emission type and power. 

 

   Although you may not consider your relatively modest amateur station as being at a permanent fixed location in the same sense as the monstrous NRQZ receive-only antennas, keep in mind that they are super sensitive to even minute radio signals.

   Q.  I reside in a suburb of Washington, DC.  How can I determine if my station is within the Washington, DC area government satellite earth station coordination circle?

   A. Section 1.924(e)(2) says that is within a radius of 110 miles of 38°48'00" N. Lat./76°52'00" W. Long.  Consult a map of Maryland or enter the coordinates into maps.google.com and find that the circle is around Andrews AFB.  That probably includes your location. 

    Relax!  Coordination is required only in the 17.8–19.7 GHz band.  Our amateur service has no allocation there.   

   Q.  That Line A is news to me.  I thought that 70 cm was an amateur radio band.  Where did that no transmitting on 420-430 MHz north of Line A come from?

   A.  See Section 97.303(f).  It says that the 420–430 MHz segment is allocated to the amateur service in the United States on a secondary basis, and is allocated in the fixed and mobile (except aeronautical mobile) services in the International Table of allocations on a primary basis. No amateur station transmitting in this band shall cause harmful interference to, nor is protected from interference due to the operation of, stations authorized by other nations in the fixed and mobile (except aeronautical mobile) services.

   Further, it says that the 430–440 MHz segment is allocated to the amateur service on a secondary basis in ITU Regions 2 and 3. No amateur station transmitting in this band in ITU Regions 2 and 3 shall cause harmful interference to, nor is protected from interference due to the operation of, stations authorized by other nations in the radiolocation service. In ITU Region 1, the 430–440 MHz segment is allocated to the amateur service on a co-primary basis with the radiolocation service. As between these two services in this band in ITU Region 1, the basic principle that applies is the equality of right to operate. Amateur stations authorized by the United States and radiolocation stations authorized by other nations in ITU Region 1 shall operate so as not to cause harmful interference to each other.

   Finally, it says that no amateur station transmitting in the 449.75–450.00 MHz segment shall cause interference to, nor is protected from interference due to the operation of stations in, the space operation and space research services.

   For more information on Line A, see http://www.fcc.gov/oet/info/maps/canline/linea.html.

    Let’s jealously guard our reputation for being good spectrum sharing neighbors.

   Q.  The FCC no longer requests the location of operation of an amateur station on the application and no specific location is stated on the license grant.  Does this mean that an amateur station does not have a permanent fixed location and therefore is not required to be compliant with Section 1.924 with the exception of a beacon station as detailed in Part 97?

   A.  You might make that argument.  There will be no guarantee of success from here.

   The more likely meaning, however, is that the concern is for our amateur stations that would be transmitting from the same location and causing interference for extended periods of time.    

   Q.  There are requirements for notification of a FCC monitoring station in Section 1.924 that are not as detailed and are not the same as in Section 97.13(b).  Which section is an amateur operator guided by? 

   A.  Both.  The operative rule is Section 97.121.  Paragraph (b) therein says:  In general, such steps as may be necessary to minimize interference to stations operating in other services may be required after investigation by the FCC.    Failure to do so could result in imposition of operating restrictions upon the amateur station.

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January 11, 2012

Supersedes all prior versions