Artikel 143

(1) The radiotelephone installation shall include transmitting and receiving equipment and appropriate sources of energy (referred to in this Regulation as the transmitter, the receiver, the radiotelephone distress frequency watch receiver, and the source of energy respectively).
(2) The transmitter shall be capable of transmitting on the radiotelephone distress frequency and on at least one other frequency in the bands between 1 605 kilohertz and 2 850 kilohertz, using the classes of emission assigned by the Radio Regulations for these frequencies. In normal operation a double sideband transmission or a single sideband transmission with full carrier (i.e. A3H) shall have a depth of modulation of at least 70 per cent at peak intensity. Modulation of a single sideband transmission with reduced or suppressed carrier (A3A, A3J) shall be such that the unwanted emission shall not exceed the values given in the Radio Regulations.
(3) (a) In vessels of 45 metres in length and over, the transmitter shall have a minimum normal range of 150 miles and shall be capable of transmitting clearly perceptible signals from ship to ship by day and under normal conditions and circumstances over this range. (Clearly perceptible signals will normally be received if the root mean square value of the field strength produced at the receiver by an unmodulated carrier is at least 25 microvolts per metre for A3 and A3H emissions.)
(b) In vessels of less than 45 metres in length the transmitter shall produce a power in the antenna of at least 15 watts for A3 emission or 60 watts for A3H emission. In any case the transmitter shall have a minimum normal range of at least 75 miles.
(a) In vessels of 45 metres in length and over, the transmitter shall have a minimum normal range of 150 miles and shall be capable of transmitting clearly perceptible signals from ship to ship by day and under normal conditions and circumstances over this range. (Clearly perceptible signals will normally be received if the root mean square value of the field strength produced at the receiver by an unmodulated carrier is at least 25 microvolts per metre for A3 and A3H emissions.)
(b) In vessels of less than 45 metres in length the transmitter shall produce a power in the antenna of at least 15 watts for A3 emission or 60 watts for A3H emission. In any case the transmitter shall have a minimum normal range of at least 75 miles.
(4) The transmitter shall be fitted with a device for generating the radiotelephone alarm signal by automatic means so designed as to prevent actuation by mistake. The device shall be capable of being taken out of operation at any time in order to permit the immediate transmission of a distress message. Arrangements shall be made to check periodically the proper functioning of the device on frequencies other than the radiotelephone distress frequency using a suitable artificial antenna.
(5) The device required by paragraph (4) shall comply with the following requirements: (a) the tolerance of the frequency of each tone shall be plus or minus 1.5 per cent;
(b) the tolerance on the duration of each tone shall be plus or minus 50 milliseconds;
(c) the interval between successive tones shall not exceed 50 milliseconds; and
(d) the ratio of the amplitude of the stronger tone to that of the weaker shall be within the range of 1 to 1.2.
(a) the tolerance of the frequency of each tone shall be plus or minus 1.5 per cent;
(b) the tolerance on the duration of each tone shall be plus or minus 50 milliseconds;
(c) the interval between successive tones shall not exceed 50 milliseconds; and
(d) the ratio of the amplitude of the stronger tone to that of the weaker shall be within the range of 1 to 1.2.
(6) The receiver required by paragraph (1) shall be capable of receiving the radiotelephone distress frequency and at least one other frequency available for maritime radiotelephone stations in the bands between 1 605 kilohertz and 2 850 kilohertz, using the classes of emission assigned by the Radio Regulations for these frequencies. In addition the receiver shall permit the reception of such other frequencies, using the classes of emission assigned by the Radio Regulations, as are used for the transmission by radiotelephony of meteorological messages and such other communications relating to the safety of navigation as may be considered necessary by the Administration. The receiver shall have sufficient sensitivity to produce signals by means of a loudspeaker when the receiver input is as low as 50 microvolts.
(7) The radiotelephone distress frequency watch receiver shall be pre-set to this frequency. It shall be provided with a filtering unit or a device to silence the loudspeaker in the absence of a radiotelephone alarm signal. The device shall be capable of being easily switched in and out and may be used when, in the opinion of the skipper, conditions are such that maintenance of the listening watch would interfere with the safe navigation of the vessel.
(8) To permit rapid change-over from transmission to reception when manual switching is used, the control for the switching device shall, where practicable, be located on the microphone or the telephone handset.
(9) (a) While the vessel is at sea, there shall be available at all times a main source of energy sufficient to operate the installation over the normal range required in paragraph (3).
(b) A reserve source of energy shall be provided: (i) in the upper part of vessels of 45 metres in length and over; and
(ii) in a position as high as practicable in vessels of less than 45 metres in length, which under all circumstances shall have sufficient capacity to operate the transmitter and receiver for at least 6 hours continuously under normal working conditions.
(i) in the upper part of vessels of 45 metres in length and over; and
(ii) in a position as high as practicable in vessels of less than 45 metres in length,
(c) If the reserve source of energy supplies several of the radio installations mentioned in paragraph (10) its capacity shall be sufficient to operate the transmitter and receiver of these installations continuously and simultaneously for at least 6 hours unless one switchgear permits the selective operation of the radio installations.
(d) The reserve source of energy may also be used as the main source of energy, provided that the manner of installation and use is such that these requirements are met at all times when the vessel is at sea.
(e) A reserve source of energy is not required for the radiotelephone installation if a reserve medium frequency radiotelegraph installation with a reserve source of energy is fitted.
(a) While the vessel is at sea, there shall be available at all times a main source of energy sufficient to operate the installation over the normal range required in paragraph (3).
(b) A reserve source of energy shall be provided: (i) in the upper part of vessels of 45 metres in length and over; and
(ii) in a position as high as practicable in vessels of less than 45 metres in length, which under all circumstances shall have sufficient capacity to operate the transmitter and receiver for at least 6 hours continuously under normal working conditions.
(i) in the upper part of vessels of 45 metres in length and over; and
(ii) in a position as high as practicable in vessels of less than 45 metres in length,
(c) If the reserve source of energy supplies several of the radio installations mentioned in paragraph (10) its capacity shall be sufficient to operate the transmitter and receiver of these installations continuously and simultaneously for at least 6 hours unless one switchgear permits the selective operation of the radio installations.
(d) The reserve source of energy may also be used as the main source of energy, provided that the manner of installation and use is such that these requirements are met at all times when the vessel is at sea.
(e) A reserve source of energy is not required for the radiotelephone installation if a reserve medium frequency radiotelegraph installation with a reserve source of energy is fitted.
(10) The reserve source of energy shall be used to supply only: (a) the radiotelephone installation;
(b) the radiotelegraph installation or the reserve radiotelegraph installation, including the radiotelegraph auto alarm and the device required by Regulation 137(12) for keying radiotelegraph alarm signals if electrically operated;
(c) the VHF installation;
(d) the emergency light required by Regulation 142(5); and
(e) the device required by paragraph (4) for generating the radiotelephone alarm signal.
(a) the radiotelephone installation;
(b) the radiotelegraph installation or the reserve radiotelegraph installation, including the radiotelegraph auto alarm and the device required by Regulation 137(12) for keying radiotelegraph alarm signals if electrically operated;
(c) the VHF installation;
(d) the emergency light required by Regulation 142(5); and
(e) the device required by paragraph (4) for generating the radiotelephone alarm signal.
(11) Notwithstanding the provisions of paragraph (10), the Administration may authorize the use of the reserve source of energy for a direction-finder, if fitted, and for a number of low-power emergency circuits which are wholly confined to the upper part of the vessel such as emergency lighting on the embarkation station for survival craft, on condition that the additional loads can be readily disconnected, and that the source of energy is of sufficient capacity to carry them.
(12) While the vessel is at sea, any battery provided shall be kept charged so as to meet the requirements of paragraph (9) and in any case shall be capable of being brought to a fully charged state within a period of 16 hours.
(13) An antenna shall be provided and installed and, if suspended between supports liable to whipping, shall be protected against breakage. In addition, a spare antenna shall be carried on board completely assembled for immediate replacement or, where this is not practicable, sufficient antenna wire and insulators to enable a spare antenna to be erected. The necessary tools to erect an antenna shall also be provided.