Goto Section: 74.638 | 74.643 | Table of Contents
FCC 74.641
Revised as of October 1, 2007
Goto Year:2006 |
2008
Sec. 74.641 Antenna systems.
(a) For fixed stations operating above 2025 MHz, the following standards
apply:
(1) Fixed TV broadcast auxiliary stations shall use directional antennas
that meet the performance standards indicated in the following table. Upon
adequate showing of need to serve a larger sector, or more than a single
sector, greater beamwidth or multiple antennas may be authorized. Applicants
shall request, and authorization for stations in this service will specify,
the polarization of each transmitted signal. Booster station antennas having
narrower beamwidths and reduced sidelobe radiation may be required in
congested areas, or to resolve interference problems.
(i) Stations must employ an antenna that meets the performance standards for
Category B. In areas subject to frequency congestion, where proposed
facilities would be precluded by continued use of a Category B antenna, a
Category A antenna must be employed. The Commission may require the use of a
high performance antenna where interference problems can be resolved by the
use of such antennas.
(ii) Licensees shall comply with the antenna standards table shown in this
paragraph in the following manner:
(A) With either the maximum beamwith to 3 dB points requirement or with the
minimum antenna gain requirement; and
(B) With the minimum radiation suppression to angle requirement.
Antenna Standards
Frequency (MHz) Category Maximum beamwidth to 3 dB points^1(included angle
in degrees) Minimum antenna gain (dbi) Minimum radiation suppression to
angle in degrees from centerline of main beam in decibels
5 ° to 10 ° 10 ° to 15 ° 15 ° to 20 ° 20 ° to 30 ° 30 ° to 100 ° 100 ° to 140 ° 140 ° to
180 °
1,990 to 2,110 A
B 5.0
8.0 n/a
n/a 12
5 18
18 22
20 25
20 29
25 33
28 39
36
6,875 to 7,125 A
B 1.5
2.0 n/a
n/a 26
21 29
25 32
29 34
32 38
35 41
39 49
45
12,700 to 13,250 A
B 1.0
2.0 n/a
n/a 23
20 28
25 35
28 39
30 41
32 42
37 50
47
17,700 to 19,700 A
B 2.2
2.2 38
38 25
20 29
24 33
28 36
32 42
35 55
36 55
36
^1If a licensee chooses to show compliance using maximum beamwith to 3 dB
points, the beamwidth limit shall apply in both the azimuth and the
elevation planes.
(2) New periscope antenna systems will be authorized upon a certification
that the radiation, in a horizontal plane, from an illuminating antenna and
reflector combination meets or exceeds the antenna standards of this
section. This provision similarly applies to passive repeaters employed to
redirect or repeat the signal from a station's directional antenna system.
(3) The choice of receiving antennas is left to the discretion of the
licensee. However, licensees will not be protected from interference which
results from the use of antennas with poorer performance than identified in
the table of this section.
(4) [Reserved]
(5) Pickup stations are not subject to the performance standards herein
stated.
(b) All fixed stations are to use antenna systems in conformance with the
standards of this section. TV auxiliary broadcast stations are considered to
be located in an area subject to frequency congestion and must employ a
Category A antenna when:
(1) A showing by an applicant of a new TV auxiliary broadcast station or
Cable Television Relay Service (CARS) station, which shares the 12.7–13.20
GHz band with TV auxiliary broadcast, indicates that use of a category B
antenna limits a proposed project because of interference, and
(2) That use of a category A antenna will remedy the interference thus
allowing the project to be realized.
(c) As an exception to the provisions of this section, the FCC may approve
requests for use of periscope antenna systems where a persuasive showing is
made that no frequency conflicts exist in the area of proposed use. Such
approvals shall be conditioned to a standard antenna as required in
paragraph (a) of this section when an applicant of a new TV auxiliary
broadcast or Cable Television Relay station indicates that the use of the
existing antenna system will cause interference and the use of a category A
or B antenna will remedy the interference.
(d) As a further exception to the provision of paragraph (a) of this
section, the Commission may approve antenna systems not conforming to the
technical standards where a persuasive showing is made that:
(1) Indicates in detail why an antenna system complying with the
requirements of paragraph (a) of this section cannot be installed, and
(2) Includes a statement indicating that frequency coordination as required
in Sec. 74.604 (a) was accomplished.
[ 45 FR 78693 , Nov. 26, 1980, as amended at 49 FR 7131 , Feb. 27, 1984; 49 FR 37778 , Sept. 26, 1984; 50 FR 7342 , Feb. 22, 1985; 51 FR 19840 , June 3, 1986;
52 FR 7143 , Mar. 9, 1987; 55 FR 11587 , Mar. 29, 1990; 56 FR 50663 , Oct. 8,
1991; 62 FR 4922 , Feb. 3, 1997; 68 FR 12771 , Mar. 17, 2003]
Goto Section: 74.638 | 74.643
Goto Year: 2006 |
2008
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