§ 81.530 Technical requirements.

The authorized frequency tolerance, authorized class of emission, authorized emission-bandwidth, and authorized transmitter power for shipyard base stations and shipyard mobile stations shall be the same as is designated for coast stations in Subpart E of this part.

§ 81.531 Cooperative use of facilities.

If, in a particular geographic area, the use and operation of shipyard mobile stations and shipyard base stations by a plurality of station licensees using the same frequency assignment(s) causes intolerable interference, even though all provisions of this part relative to the reduction of interference have been fully complied with, the Commission may, in accordance with the provisions of the Communications Act, require the involved station licensees to join in a single cooperative organization for rendition of the necessary land mobile service within the affected area by a single station licensee.

§ 81.532 General operating procedure.

(a) All communication engaged in by shipyard base and mobile stations shall be limited to the minimum practicable transmission time, and each station licensee shall employ standardized operating practices and procedures to this effect.

(b) Each licensee of shipyard mobile stations shall exercise such control over the transmissions of those stations as is necessary to avoid interference to calls from ship stations which may be transmitted on the radio-channel used by the shipyard mobile stations.

(c) Calling a particular station, either by voice or by other means, shall not continue for a period of more than 30 seconds in each instance. If the called station is not heard to reply, that station shall not again be called until after an interval of three minutes. In event of an emergency involving safety, these time limitations shall not apply.

(d) Shipyard base stations may use authorized classes of emission for the selective calling of shipyard mobile stations on each radio-channel authorized

for communication between such base and mobile stations.

§ 81.533 Identification of stations.

(a) All emissions of a shipyard base station shall be clearly identified by voice transmission therefrom in the English language of either (1) the official call sign assigned to that station (the official call sign assigned to the same station as a coast station in accordance with § 81.72) by the Commission, or (2) the name of the station licensee (in abbreviated form if practicable) as formally reported to and approved by the Commission; if the licensee operates more than one shipyard base station within mutual interference range, the name of the licensee shall be followed by a digit indicating distinctly the respective land station, as formally reported to the Commission.

(b) All emissions of a shipyard mobile station shall be clearly identified by voice transmission in the English language of either (1) the single official call sign assigned by the Commission to the shipyard mobile station(s) of that licensee in the particular geographic area, followed by two digits indicating distinctly the respective shipyard land mobile unit as reported to the Commission, or (2) the name of the station licensee (in abbreviated form if practicable) as formally reported to and approved by the Commission, followed by two digits indicating distinctly the respective shipyard land mobile unit as reported to the Commission.

(c) Identification of stations as prescribed in this section shall be made: (1) Whenever another station called;

19

(2) Upon completion of each communication with any other station;

(3) At the beginning and upon completion of each transmission made for any other purpose.

§ 81.534 Procedure in testing.

With respect to test transmission, the provisions of § 81.367 which apply to limited coast stations and marine-utility stations shall apply also to shipyard base stations and shipyard mobile stations: Provided, That the term "licensed radio

operation" as used in paragraph (a) (1) of that section shall, with respect to test operation of shipyard mobile stations pursuant to this section, be construed in each instance to mean the operator Hicensee on duty at the control point of the associated shipyard base station as provided in § 81.156 (a) (1).

§ 81.535 Station documents.

(a) With respect to documents required to be available at a shipyard base station, the provisions of § 81.369 which apply to limited coast stations using telephony shall apply also to shipyard base

stations.

'b' Each shipyard mobile station shall be provided with the following documents during its hours of service:

1) A valid station authorization, available in accordance with § 81.102.

(2) The necessary operator license(s), available in accordance with the provisions of § 81.159 this requirement is not applicable when the station is operated under the provision of § 81.158.

28 FR. 1404. Dec. 21, 1963, as amended at 32 F.R. 13664, Sept. 29, 1967] § 81.536 Station records.

a 1 With respect to station records required to be maintained by a shipyard base station, the provisions of | 81.370 which apply to limited coast stations using telephony shall apply also to shipyard base stations.

2. Each licensee of a land station operated as a shipyard base station shall, upon specific request made by the Commission, be responsible for the submission of such reports as are requested by the Commission to show the value and practical performance of that station and the associated shipyard mobile station(s) in the land mobile service in relation to the maritime mobile service for which the same land station is licensed.

by Unless otherwise determined by the Commission subsequent to pertinent developments in the use and operation of shipyard mobile stations, no station records need be maintained by those stations upon the express condition that (1) such station records as are required by

other applicable sections of this part (imcluding §§ 81.109, 81.110, and 81.111) are maintained as part of the required records of the associated shipyard base station, and (2) the records of the lamer station with respect to the log entries required by § 81.370(a) (7), (8) and (9) shall include the specified informamon concerning the involved shipyard mobile station(s).

Subpart O-Violations

SOURCE: The provisions of this SubpaT O appear at 28 FR. 14006, Dec. 21, 1961 unless otherwise noted.

§ 81.551 Answers to notice of violation.

Any person receiving official notice of a violation of the terms of the Comm cations Act, any legislative act, Execu tive order, treaty to which the United States is a party, terms of a stanom or operator license, or the rules and regulations of the Federal Communicamoms Commission, shall, within ten days from such receipt, send a written answer, I duplicate, to the office of the Comm sion originating the official notice. ** an answer cannot be sent, or an acknowledgment made within such ten-day period by reason of illness or other avoidable circumstances, acknowledgment and answer shall be made at the earliest practicable date with a satisfactory explanation of the delay. The answer to each notice shall be complete in itself and shall not be abbreviated T reference to other communicamoms I answers to other notices. The answer shall contain a full explanation of the incident involved and shall set forth the action taken to prevent a continmaTICE or recurrence thereof. If the notice relates to lack of attention to, or improper operation of the station, or to log watch discrepancies, the answer shat give the name and license number of the Licensed operator on duty. § 81.552

Reports of infringements

the International Radio Regulations. In the event that infringement of the International Radio Regulations by a foreign station is detected, report thereaf may be made by the submission to the

SOURCE: The provisions of this Subpart P appear at 32 F.R. 6935, unless otherwise noted.

§ 81.601

Service authorized.

Operational fixed stations associated with the maritime mobile service consist of marine control stations, marine repeater stations, and marine relay stations which are authorized for service as follows:

(a) Marine control stations: to transmit exclusively to the particular coast station whose operation or emission is being controlled.

(b) Marine repeater stations: to transmit exclusively to other authorized marine repeater stations, or to designated radio receiving locations to which the respective transmitted communication is addressed, or to an authorized message center at a designated fixed location.

(c) Marine relay stations: to transmit to and receive from other authorized marine relay stations as specified in the station authorization.

1 These frequencies are available on a shared basis with the Manufacturers Radio Service.

(b) The frequencies listed in paragraph (a) of this section are assignable under the following conditions:

(1) In any area in the United States (including Alaska) a maximum of four frequencies may be assigned to operational fixed stations.

(2) All authorizations are subject to the condition that no harmful interference shall be caused to the service of existing and previously authorized operational fixed stations.

(3) If the Commission finds that the the public interest, convenience, or necessity would be served thereby, licensees of operational fixed stations authorized to operate on one or more of the frequencies specified in paragraph (a) of this section shall be required to share, on a coordinated noninterference basis, the use of their respective frequency assignments with other licensees using the same frequencies.

(4) All authorizations are subject to the condition that no harmful interference will be caused to television reception on Channels 4 and 5.

(5) The applicant agrees to eliminate any harmful interference caused by his operation to TV reception on either Channel 4 or 5, that might develop, by whatever means are found necessary, within 90 days of the time knowledge of said interference is first brought to his attention by the Commission. If said interference is not cleared up within the 90-day period, operation of the fixed station will be discontinued.

(6) Vertical polarization must be used. (7) Whenever it is proposed to locate a 72-76 Mc s fixed station less than 80, but more than 10 miles from the site of a TV transmitter operating on either Channel 4 or 5, or from the post office of a commonly in which such channels are assigned but are not in operation, the fixed station shall be authorized only if there are fewer than 100 family dwelling units (as defined by the U.S. Bureau of Census located within a circle centered at the location of the proposed fixed station family dwelling Trains 70 or more miles distant from the TV antenna site are not to be counted) the radios of which shall be determined by use of the chart entitled, "Chart for Determining Radius from Fixed Station in 72-76 Mes Band to Interference Contour Along Which 10 Percent of Service From Adjacent Channel Television Station Would Be Destroyed." Two charts are provided, one for Cham mel 4 and one for Channel 5. The Commission may, however, in a particular case, authorize the location of a

The applicant has a plam to control any interference that might develop 10 TV reception from s operations.

iv) The applicant is financially abie and agrees to make such adjustments in the TV receivers affected as may be necessary To eliminate terference caused by his operations.

8. All applications for authority to operate with a separation of less than 10 miles from the site of a TV transmitter operating on either Channel 4 or 5. c from the post office of a comety in which such channels are assigned bus are not in operation, will be returned without action. (See charts.)

L G

transmission line efficiency, %

power gain of the antenna with respect to a half
wave dipole in free space.

For a directional antenna use the power in the main lobe.

h-height in feet of the center of the transmitting antenna array of the fixed 72-76 Mc/s station with respect to the average level of the terrain between 2 and 10 miles from such antenna in the direction of the TV station. (The method for determining this height is explained in detail in the TV Broadcast Rules.)

separation in miles between the television station antenna and the 72-76 Mc/s fixed station antenna.

20

1000

3. Where the second line intersects the S-r curves, read the value of r for the appropriate value of 5.