Goto Section: 90.241 | 90.243 | Table of Contents
FCC 90.242
Revised as of October 1, 2011
Goto Year:2010 |
2012
§ 90.242 Travelers' information stations.
(a) The frequencies 530 through 1700 kHz in 10 kHz increments may be
assigned to the Public Safety Pool for the operation of Travelers'
Information Stations subject to the following conditions and
limitations.
(1) [Reserved]
(2) Each application for a station or system shall be accompanied by:
(i) A statement certifying that the transmitting site of the Travelers'
Information Station will be located at least 15 km (9.3 miles) measured
orthogonally outside the measured 0.5 mV/m daytime contour (0.1 mV/m
for Class A stations) of any AM broadcast station operating on a first
adjacent channel or at least 130 km (80.6 miles) outside the measured
0.5 mV/m daytime contour (0.1 mV/m for Class A stations) of any AM
broadcast station operating on the same channel, or, if nighttime
operation is proposed, outside the theoretical 0.5 mV/m-50% nighttime
skywave contour of a U.S. Class A station. If the measured contour is
not available, then the calculated 0.5 mV/m field strength contour
shall be acceptable. These contours are available at the concerned AM
broadcast station and FCC offices in Washington, DC.
(ii) In consideration of possible cross-modulation and inter-modulation
interference effects which may result from the operation of a
Travelers' Information Station in the vicinity of an AM broadcast
station on the second or third adjacent channel, the applicant shall
certify that it has considered these possible effects and, to the best
of its knowledge, does not foresee interference occurring to broadcast
stations operating on second or third adjacent channels.
(iii) A map showing the geographical location of each transmitter site
and an estimate of the signal strength at the contour of the desired
coverage area. For a cable system, the contour to be shown is the
estimated field strength at 60 meters (197 feet) from any point on the
cable. For a conventional radiating antenna, the estimated field
strength contour at 1.5 km (0.93 mile) shall be shown. A contour map
comprised of actual on-the-air measurements shall be submitted to the
Commission within 60 days after station authorization or completion of
station construction, whichever occurs later. A sufficient number of
points shall be chosen at the specified distances (extrapolated
measurements are acceptable) to adequately show compliance with the
field strength limits.
(iv) For each transmitter site, the transmitter's output power, the
type of antenna utilized, its length (for a cable system), its height
above ground, distance from transmitter to the antenna, and the
elevation above sea level at the transmitting site.
(3) Travelers' Information Stations will be authorized on a primary
basis on 530 kHz and on a secondary basis to stations authorized on a
primary basis in the band 535-1705 kHz.
(4) A Travelers' Information Station authorization may be suspended,
modified, or withdrawn by the Commission without prior notice or right
to hearing if necessary to resolve interference conflicts, to implement
agreements with foreign governments, or in other circumstances
warranting such action.
(5) The transmitting site of each Travelers' Information Station shall
be restricted to the immediate vicinity of the following specified
areas: Air, train, and bus transportation terminals, public parks and
historical sites, bridges, tunnels, and any intersection of a Federal
Interstate Highway with any other Interstate, Federal, State, or local
highway.
(6) A Travelers' Information Station shall normally be authorized to
use a single transmitter. However, a system of stations, with each
station in the system employing a separate transmitter, may be
authorized for a specific area provided sufficient need is demonstrated
by the applicant.
(7) Travelers' Information Stations shall transmit only noncommercial
voice information pertaining to traffic and road conditions, traffic
hazard and travel advisories, directions, availability of lodging, rest
stops and service stations, and descriptions of local points of
interest. It is not permissible to identify the commercial name of any
business whose service may be available within or outside the coverage
area of a Travelers' Information Station. However, to facilitate
announcements concerning departures/arrivals and parking areas at air,
train, and bus terminals, the trade name identification of carriers is
permitted.
(b) Technical standards. (1) The use of 6K00A3E emission will be
authorized, however N0N emission may be used for purposes of receiver
quieting, but only for a system of stations employing "leaky" cable
antennas.
(2) A frequency tolerance of 100 Hz shall be maintained.
(3) For a station employing a cable antenna, the following restrictions
apply:
(i) The length of the cable antenna shall not exceed 3.0 km (1.9
miles).
(ii) Transmitter RF output power shall not exceed 50 watts and shall be
adjustable downward to enable the user to comply with the specified
field strength limit.
(iii) The field strength of the emission on the operating frequency
shall not exceed 2 mV/m when measured with a standard field strength
meter at a distance of 60 meters (197 feet) from any part of the
station.
(4) For a station employing a conventional radiating antenna(s) (ex.
vertical monopole, directional array) the following restrictions apply:
(i) The antenna height above ground level shall not exceed 15.0 meters
(49.2 feet).
(ii) Only vertical polarization of antennas shall be permitted.
(iii) Transmitter RF output power shall not exceed 10 watts to enable
the user to comply with the specified field strength limit.
(iv) The field strength of the emission on the operating frequency
shall not exceed 2 mV/m when measured with a standard field strength
meter at a distance of 1.50 km (0.93 miles) from the transmitting
antenna system.
(5) For co-channel stations operating under different licenses, the
following minimum separation distances shall apply:
(i) 0.50 km (0.31 miles) for the case when both stations are using
cable antennas.
(ii) 7.50 km (4.66 miles) for the case when one station is using a
conventional antenna and the other is using a cable antenna.
(iii) 15.0 km (9.3 miles) for the case when both stations are using
conventional antennas.
(6) For a system of co-channel transmitters operating under a single
authorization utilizing either cable or conventional antennas, or both,
no minimum separation distance is required.
(7) An applicant desiring to locate a station that does not comply with
the separation requirements of this section shall coordinate with the
affected station.
(8) Each transmitter in a Travelers Information Station shall be
equipped with an audio low-pass filter. Such filter shall be installed
between the modulation limiter and the modulated stage. At audio
frequencies between 3 kHz and 20 kHz this filter shall have an
attenuation greater than the attenuation at 1 kHz by at least:
60 log[10](f/3) decibels.
where "f" is the audio frequency in kHz. At audio frequencies above 20
kHz, the attenuation shall be at least 50 decibels greater than the
attenuation at 1 kHz.
[ 43 FR 54791 , Nov. 22, 1978; 44 FR 67118 , Nov. 23, 1979; 49 FR 48712 ,
Dec. 14, 1984, as amended at 54 FR 39740 , Sept. 28, 1989; 56 FR 64874 ,
Dec. 12, 1991; 62 FR 18928 , Apr. 17, 1997; 65 FR 60877 , Oct. 13, 2000;
67 FR 63289 , Oct. 11, 2002; 72 FR 35195 , June 27, 2007; 73 FR 25497 ,
May 6, 2008]
Goto Section: 90.241 | 90.243
Goto Year: 2010 |
2012
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