[Code of Federal Regulations]
[Title 47, Volume 5]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR90.242]
[Page 356-358]
TITLE 47--TELECOMMUNICATION
CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)
PART 90_PRIVATE LAND MOBILE RADIO SERVICES--Table of Contents
Subpart J_Non-Voice and Other Specialized Operations
Sec. 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
[[Page 357]]
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
secondary basis to stations authorized on a primary basis in the band
510-1715 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
[[Page 358]]
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<INF>10</INF> (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]