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Quiet Zone Directory
John B. Johnston W3BE
certain areas at places where the FCC regulates our amateur service, it is necessary for the radiation intensity transmitted from our stations to be restricted so as to minimize possible disruption
on radio astronomy and other RF-sensitive reception. Let’s be good spectrum sharers. Know where those quiet zones are
located and avoid transmissions being made by your amateur station from within them.
Except for automatically controlled beacons – discussed below -
most of our amateur station transmissions can be characterized as short-term intermittent low to medium power communications.
As such, they should pose little or no disruption to most quiet zone reception. But it is best to check with the area frequency
coordinator or field office supervisor for assurance that your station’s transmissions are such as to minimize any possible
negative impact highly sensitive radio reception in the Quiet Zone.
The following is a summary of the quiet zones codified in Part 97 and Part 1.
from Part 97
NRQZ (National Radio Quiet Zone), defined in Section 97.3(a)(33) as the area in Maryland, Virginia, and West Virginia Bounded by 39°15' N on the north, 78°30' W on the east,
37°30' N on the south and 80°30' W on the west. Section 97.203(e) says: Before establishing an automatically controlled beacon in the National Radio Quiet Zone or before changing the
transmitting frequency, transmitter power, antenna height or directivity, the station licensee must give written notification
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 facilities. Section 97.13(b) says that a station within 1 mile of an FCC monitoring facility must protect that facility from harmful interference.
Failure to do so could result in imposition of operating restrictions upon the amateur station by a District Director pursuant
to 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. Geographical coordinates of the protected field offices that
require protection are listed in Section 0.121(c) together with their geographical coordinates. They are: date of notification, the FCC will take whatever action is deemed
Section 97.3(a)(9) defines a beacon as an amateur station transmitting communications for the purposes of observation of propagation and
reception or other related experimental activities.
Section 97.3(a)(6) defines automatic control as the use or devices and procedures for control of a station while it is transmitting so that
compliance with the FCC Rules is achieved without the control operator being present at the control point.
Section 97.203(d) authorizes a beacon to be automatically controlled while it is transmitting on certain frequency segments and bands.
Also, read and heed NRQZ under the
rubric Part 1 below.
Other areas where amateur station transmissions may be restricted are near FCC monitoring stations:
Kenai, Alaska, 60°43'26.0"
N. Latitude, 151°20'15.0" W. Longitude
Douglas, Arizona, 31°30'02.3" N. Latitude, 109°39'14.3" W. Longitude
Powder Springs, Georgia,
33°51'44.4" N. Latitude, 84°43'25.8" W. Longitude
Waipahu, Hawaii, 21°22'33.6" N. Latitude, 157°59'44.1" W. Longitude
Maine, 44°26'42.3" N. Latitude, 69°04'56.1" W. Longitude
Laurel, Maryland, 39°09'54.4" N. Latitude, 76°49'15.9"
Michigan, 42°36'20.1" N. Latitude, 85°57'20.1" W. Longitude
Grand Island, Nebraska, 40°55'21.0" N. Latitude,
98°25'43.2" W. Longitude
Canandaigua, New York, 42°54'48.2" N. Latitude, 77°15'57.9" W. Longitude
Santa Isabel, Puerto Rico,
18°00'18.9" N. Latitude, 66°22'30.6" W. Longitude
Ferndale, Washington, 48°57'20.4" N. Latitude, 122°33'17.6" W. Longitude
Kingsville, Texas, 27°26'30.1"
N. Latitude, 97°53'01.0" W. Longitude
Also, read and heed
FCC protected field offices under the rubric Excerpts from Part 1 below.
While not designated as quiet zones, there are areas where amateur stations must not transmit because of the sharing
requirements codified in Section 97.303. One such wide-ranging area is along our entire northern United States border with Canada. By Section 97.301(a), amateur stations are authorized to transmit in the 420-450 MHz 70 cm band subject to the sharing requirements codified in
Sections 97.303(a), (b), and (f). Section 97.303(f)(1) says that no amateur station shall transmit from north of Line A in the 420–430 MHz segment. Section 97.3(a)(30) says:
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.
There should be, therefore, no 420-430 MHz
transmissions by amateur stations from north of Line A within the United States.
Excerpts from Part 1
NRQZ: National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, West Virginia,
and the Naval Radio Research Observatory site at Sugar Grove, Pendleton County, West Virginia. Read Section 1.924(a). The more inclusive requirements of this paragraph are to minimize possible interference over the specific protection against
automatically-controlled amateur radio beacon stations codified in Section 97.203(e).
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: firstname.lastname@example.org.
FCC protected field offices: Section 1.924(c) 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.
For a listing of the FCC monitoring facilities where amateur station transmissions may be restricted see Other Areas under
the rubric Excerpts from Part 97 above.
Observatory, Puerto Rico: Section 1.924(d) says that licensees must make reasonable efforts to protect the Observatory from interference. Licensees planning to
construct and operate a new station at a permanent fixed location on the islands of Puerto Rico, Desecheo, Mona, Vieques or
Culebra in services in which individual station licenses are issued by the FCC; planning to construct and operate a new station
at a permanent fixed location on these islands that may cause interference to the operations of the Arecibo Observatory in
services in which individual station licenses are not issued by the FCC; or planning a modification of any existing station
at a permanent fixed location on these islands that would increase the likelihood of causing interference to the operations
of the Arecibo Observatory must notify the Interference Office, Arecibo Observatory, HC3 Box 53995, Arecibo, Puerto Rico 00612,
in writing or electronically (e-mail address: email@example.com), of the technical parameters of the planned operation.
In our amateur radio service, this provision does not apply to repeaters that transmit on the 1.2 cm or shorter wavelength
bands; and the coordination provision does not apply to repeaters that are located 9.942 miles or more from the Arecibo observatory.
Satellite Earth Stations: Located in the Denver, Colorado and Washington, DC
areas. Read Section 1.924(e). Coordination is required in the 17.8–19.7 GHz band. Our amateur service has no allocation there.
MHz band: Section 1.924(f) says that applicants should not expect to be accommodated if their area of service is:
(w)ithin 100 miles of 41°45'00.2" N, 70°30'58.3" W.
(Massachusetts), 64°17'00.0" N., 149°10'00.0" W. (Alaska), 48°43'00.0" N., 97°54'01.4"
W. (North Dakota);
within 124 miles of 32°38'00.5" N., 83°34'59.7" W. (Georgia), 31°25'00.6" N., 100°24'01.3"
Or within 150
miles of 39°07'59.6" N., 121°26'03.9" W. (California);
Or within 200 miles of 28°21'01.0" N., 80°42'59.2" W. (Florida),
30°30'00.7" N., 86°29'59.8" W. (Florida), 34°08'59.6" N, 119°11'03.8" W. (California);
Or in Arizona, Florida, portions of California
and Nevada south of 37°10' N. and portions of Texas and New Mexico bounded by 31°45' N., 34°30' N., 104°00'
W., and 107°30' W.
Geostationary Operational Environmental Satellite Earth stations receiving in the band 1670–1675 MHz, which are located at Wallops Island,
VA, Fairbanks, AK, and Greenbelt, MD. Read Section 1.924(g). It says that licensees planning to construct and operate a new or modified station within the area bounded by a circle
with a radius of 100 kilometers (62.1 miles) that is centered on 37°56'44" N, 75°27'37" W (Wallops Island)
or 64°58'22" N, 147°30'04" W (Fairbanks) or within the area bounded by a circle with a radius of 65 kilometers
(40.4 miles) that is centered on 39°00'02" N, 76°50'29" W (Greenbelt) must notify the National Oceanic and
Atmospheric Administration (NOAA) of the proposed operation. For this purpose, NOAA maintains the GOES coordination Web page
at http://www.osd.noaa.gov/radio/frequency.htm, which provides the technical parameters of the earth stations and the point-of-contact
for the notification. The notification shall include the following information: Requested frequency, geographical coordinates
of the antenna location, antenna height above mean sea level, antenna directivity, emission type, equivalent isotropically
radiated power, antenna make and model, and transmitter make and model. Licensees are required to protect the Wallops Island
and Fairbanks sites at all times. Licensees are required to protect the Greenbelt site only when it is active. Licensees should
coordinate appropriate procedures directly with NOAA for receiving notification of times when this site is active.
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 fixed 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 Hams At Sea BE Informed No. 1.6.
Q. I have a General Class license. If I take up residence near a FCC monitoring
station, would I be allowed to have a ham station?
A. Yes, because your amateur operator/primary station license grant – as it appears
on the ULS - is both an operator license and a station license. Section 97.5 - together with Section 97.301 - authorizes your station to transmit from almost anywhere the amateur service is regulated by the FCC and on and over the high seas outside any area where the amateur service is regulated by any authority other than the FCC.
Depending upon how close to the protected field office the station at your residence might be, however, operating restrictions
could be imposed by the FCC District Director.
Section 1.924(c)(1) says that licensees (you) and applicants (not you) planning to construct and operate a new or modified station at a permanent
fixed location near an FCC protected field office are advised to give consideration, prior to filing applications, to
the need to avoid interfering with the monitoring activities of that office.
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, for example, 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 QTH 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, together with 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 encounter a very low level of ambient radio noise.
Transmitting at high power, however, may be another matter. First, there
is Section 97.203(e). It 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,
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
(possibly 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. Using a map of Maryland,
draw that the circle 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)
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.
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 except for a beacon station as detailed in Part 97?
A. You might make that argument. There
is no guarantee of success. The more likely meaning is there is 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). By which section is an amateur operator to be guided?
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.
Where are the quiet zone rules for repeaters? I can’t find anything in Part 97 about not transmitting on an active repeater
input channel unless you intend to access the repeater. Is it in there and if so, where is it?
A. It is in Section 97.101(b). It simply says: Each station licensee and each control operator must cooperate in selecting transmitting channels and
in making the most effective use of the amateur service frequencies. No frequency will be assigned for the exclusive use of
amateur service community does a fine job of repeater band planning, coordination, and cooperation. Our stewardship of that
very valuable public spectrum resource is an ideal example off good citizenry.
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Supersedes all prior versions