IEC 61097-9:1997

INTERNATIONAL
IEC
STANDARD 61097-9
First edition
1997-12
Global maritime distress and safety
system (GMDSS) –
Part 9:
Shipborne transmitters and receivers for use in
the MF and HF bands suitable for telephony,
digital selective calling (DSC) and narrow band
direct printing (NBDP) – Operational and
performance requirements, methods of testing
and required test results
Système mondial de détresse et de sécurité
en mer (SMDSM) –
Partie 9:
Emetteurs et récepteurs de bord de navires utilisables dans les
bandes décamétriques et hectométriques pour la téléphonie,
l’appel sélectif numérique (ASN) et l’impression directe à bande
étroite (IDBE) – Exigences d’exploitation et de fonctionnement,
méthodes d’essai et résultats d’essai exigés
Reference number
IEC 61097-9: 1997(E)
Numéros des publications Numbering
Depuis le 1er janvier 1997, les publications de la CEI As from the 1st January 1997 all IEC publications are
sont numérotées à partir de 60000. issued with a designation in the 60000 series.
Publications consolidées Consolidated publications
Les versions consolidées de certaines publications de Consolidated versions of some IEC publications
la CEI incorporant les amendements sont disponibles. including amendments are available. For example,
Par exemple, les numéros d’édition 1.0, 1.1 et 1.2 edition numbers 1.0, 1.1 and 1.2 refer, respectively, to
indiquent respectivement la publication de base, la the base publication, the base publication
publication de base incorporant l’amendement 1, et la incorporating amendment 1 and the base publication
publication de base incorporant les amendements 1 incorporating amendments 1 and 2.
et 2.
Validité de la présente publication Validity of this publication
Le contenu technique des publications de la CEI est The technical content of IEC publications is kept under
constamment revu par la CEI afin qu'il reflète l'état constant review by the IEC, thus ensuring that the
actuel de la technique. content reflects current technology.
Des renseignements relatifs à la date de Information relating to the date of the reconfirmation of
reconfirmation de la publication sont disponibles dans the publication is available in the IEC catalogue.
le Catalogue de la CEI.
Les renseignements relatifs à ces révisions, à l'établis- Information on the revision work, the issue of revised
sement des éditions révisées et aux amendements editions and amendments may be obtained from
peuvent être obtenus auprès des Comités nationaux de IEC National Committees and from the following
la CEI et dans les documents ci-dessous: IEC sources:
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Publié annuellement et mis à jour régulièrement Published yearly with regular updates
(Accès en ligne)* (On-line access)*
Terminologie, symboles graphiques Terminology, graphical and letter
et littéraux symbols
En ce qui concerne la terminologie générale, le lecteur For general terminology, readers are referred to
se reportera à la CEI 60050: Vocabulaire Electro- IEC 60050: International Electrotechnical Vocabulary
technique International (VEI). (IEV).
For graphical symbols, and letter symbols and signs
Pour les symboles graphiques, les symboles littéraux
et les signes d'usage général approuvés par la CEI, le approved by the IEC for general use, readers are
lecteur consultera la CEI 60027: Symboles littéraux à referred to publications IEC 60027: Letter symbols to
utiliser en électrotechnique, ymboles be used in electrical technology, IEC 60417: Graphical
la CEI 60417: S
graphiques utilisables sur le matériel. Index, relevé et symbols for use on equipment. Index, survey and
compilation des feuilles individuelles, et la CEI 60617: compilation of the single sheets and IEC 60617:
Graphical symbols for diagrams.
Symboles graphiques pour schémas.
Publications de la CEI établies par IEC publications prepared by the same
le même comité d'études technical committee
The attention of readers is drawn to the end pages of
L'attention du lecteur est attirée sur les listes figurant
à la fin de cette publication, qui énumèrent les this publication which list the IEC publications issued
publications de la CEI préparées par le comité by the technical committee which has prepared the
d'études qui a établi la présente publication. present publication.
* Voir adresse «site web» sur la page de titre. * See web site address on title page.

INTERNATIONAL
IEC
STANDARD
61097-9
First edition
1997-12
Global maritime distress and safety
system (GMDSS) –
Part 9:
Shipborne transmitters and receivers for use in
the MF and HF bands suitable for telephony,
digital selective calling (DSC) and narrow band
direct printing (NBDP) – Operational and
performance requirements, methods of testing
and required test results
Système mondial de détresse et de sécurité
en mer (SMDSM) –
Partie 9:
Emetteurs et récepteurs de bord de navires utilisables dans les
bandes décamétriques et hectométriques pour la téléphonie,
l’appel sélectif numérique (ASN) et l’impression directe à bande
étroite (IDBE) – Exigences d’exploitation et de fonctionnement,
méthodes d’essai et résultats d’essai exigés
 IEC 1997 Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including
photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
XA
International Electrotechnical Commission
For price, see current catalogue

– 2 – 61097-9 © IEC:1997(E)
CONTENTS
Page
FOREWORD . 5
Clause
1 Scope . 6
2 Normative references. 7
3 Performance requirements . 8
3.1 Introduction . 8
3.2 Power supplies . 9
3.3 Control . 9
3.4 Interfaces . 9
3.5 Frequency indication. 9
3.6 Distress controls. 9
3.7 Control panel priority . 10
3.8 Labels . 10
3.9 Safety precautions. 11
3.10 Classes of emission . 11
3.11 Frequency bands. 11
3.12 Warming-up period. 11
4 Transmitter . 11
4.1 Frequencies and classes of emission. 11
4.2 Frequency accuracy and stability . 12
4.3 Output power. 12
4.4 Transmitter input . 13
4.5 Permissible warming-up period . 13
4.6 Continuous operation. 13
4.7 Controls and indicators . 13
4.8 Safety precautions. 14
4.9 Power supply. 14
4.10 Synthesizer lock . 14
4.11 Channel switching . 14
4.12 NBDP transmit and receive timing. 14
5 Receiver . 14
5.1 Frequencies and classes of emission. 14
5.2 Frequency stability and accuracy . 15
5.3 Usable sensitivity. 15
5.4 Receiver output . 15
5.5 Permissible warming-up period . 15
5.6 Immunity to interference . 15
5.7 Controls . 15

61097-9 © IEC:1997(E) – 3 –
Clause Page
5.8 Power supply. 16
5.9 Antenna static protection . 16
5.10 Loudspeaker switching . 16
5.11 Noise reducer. 16
5.12 Audio gain control and automatic gain control (AGC). 16
5.13 NBDP transmit and receive timing. 16
6 Radiotelephone alarm signal generator. 16
6.1 Introduction . 16
6.2 General . 16
6.3 Frequency and duration of tones. 17
6.4 Modulation . 17
6.5 Controls . 17
6.6 Duration of alarm signal. 17
6.7 Alarm signal repeat . 17
6.8 Activation of the radio telephone transmitter . 17
6.9 Aural monitoring . 17
7 Methods of testing and required test results . 17
7.1 Test conditions . 18
7.2 Performance check. 18
7.3 Environmental tests . 19
7.4 Electromagnetic compatibility (EMC). 19
7.5 Immunity . 19
7.6 Acoustic noise . 19
7.7 Compass safe distance . 20
7.8 Safety precautions. 20
7.9 General conditions of measurement. 20
8 Transmitter . 22
8.1 General . 22
8.2 Frequency error. 22
8.3 Output power and intermodulation products . 23
8.4 Unwanted frequency modulation . 24
8.5 Sensitivity of the microphone . 25
8.6 Sensitivity of the 600 Ω line input for SSB telephony . 25
8.7 Automatic level control and/or limiter for SSB telephony. 26
8.8 Audio frequency response using SSB telephony. 26
8.9 Power of out-of-band emissions using SSB telephony . 27
8.10 Power of conducted spurious emissions of SSB telephony . 28
8.11 Residual hum and noise power using telephony . 28
8.12 Residual frequency modulation on DSC and NBDP . 29
8.13 Carrier suppression . 29
8.14 Continuous operation. 30
8.15 Protection of the transmitter. 30
8.16 Residual RF noise power . 31
8.17 Switching time for NBDP. 31

– 4 – 61097-9 © IEC:1997(E)
Clause Page
9 Receiver . 32
9.1 Audio frequency output levels . 32
9.2 Frequency error. 32
9.3 Unwanted frequency modulation . 33
9.4 Audio frequency pass band. 34
9.5 Maximum usable sensitivity . 35
9.6 Harmonic content in output . 36
9.7 Adjacent channel selectivity. 36
9.8 Blocking . 38
9.9 Cross-modulation . 39
9.10 Intermodulation . 39
9.11 Spurious response rejection ratio. 40
9.12 Audio frequency intermodulation . 42
9.13 Conducted spurious emissions into the antenna. 43
9.14 Internally generated spurious signals . 43
9.15 Improvement in signal-to-noise ratio with AGC . 43
9.16 AGC range . 44
9.17 AGC time constants (attack and recovery time). 44
9.18 Switching time for NBDP. 45
9.19 Reciprocal mixing . 45
9.20 Protection of input circuits . 46
Figures
1 – Limits for unwanted emission (MF/HF transmitter). 47
2 – Limits for automatic level control. 48
3 – Limits for audio frequency response. 49
Annexes
A – Relationship between bit error rate (BER) input and symbol error rate (SER) output . 50
B – Bibliography . 54
C – Delays in equipment and its effect on narrow band direct printing communication
in the GMDSS using the protocol in Recommendation ITU-R M.625. 55

61097-9 © IEC:1997(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS) –
Part 9: Shipborne transmitters and receivers for use in the MF and HF
bands suitable for telephony, digital selective calling (DSC) and
narrow band direct printing (NBDP) –
Operational and performance requirements,
methods of testing and required test results
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61097-9 has been prepared by IEC technical committee 80:
Maritime navigation and radiocommunication equipment and systems.
The text of this standard is based on the following documents:
FDIS Report on voting
80/147/FDIS 80/164/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
Annexes A, B and C are for information only.
The bilingual version of this standard will be issued later.

– 6 – 61097-9 © IEC:1997(E)
GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS) –
Part 9: Shipborne transmitters and receivers for use in the MF and HF
bands suitable for telephony, digital selective calling (DSC) and
narrow band direct printing (NBDP) –
Operational and performance requirements,
methods of testing and required test results
1 Scope
This part of IEC 61097 specifies the minimum operational and performance requirements and
methods of testing with required test results for transmitters and receivers capable of voice
communication, digital selective calling and narrow band direct printing telegraphy for the
GMDSS operating in either the medium frequency band only or in medium and high frequency
bands allocated in the ITU Radio Regulations to the Maritime Mobile Service, as required by
Chapter IV of SOLAS 1974 as amended in 1988 and which is associated with IEC 60945.
When a requirement in this standard is different from IEC 60945, the requirement of this
standard shall take precedence.
This standard refers to equipment for:
– single side-band (SSB) transmission and reception for radiotelephony;
– frequency shift keying or single side-band transmission and reception for digital selective
calling signals (DSC) according to Recommendation ITU-R M.493-7; and
– frequency shift keying or single side-band transmission and reception for narrow band direct
printing telegraphy (NBDP) according to Recommendation ITU-R M.625-3;
as applicable.
This standard refers to radio equipment, which is not integrated with DSC encoders or
decoders, or NBDP modems, but defines the interfaces with, and the RF characteristics of,
such equipment.
NOTE – The requirements for integrated DSC encoders or decoders may be found in IEC 61097-3 and for
integrated NBDP modems in the future IEC 61097-11.
These requirements include the relevant provisions of the Radio Regulations and of the IMO
Resolutions A.334(IX), A.421(XI), A.694(17), A.804(19), and A.806(19) and SOLAS.
NOTE – The requirement for two-tone generators (A.421(XI)) is only applicable until 1 February 1999.
If the equipment, or parts of it, is designed in such a manner that it can be used for other
categories of maritime radiocommunication services (e.g. radio data or facsimile transmission),
those parts of the equipment shall fulfil the relevant requirements of the appropriate standards
for the service(s) in question.
NOTE – All text of this standard the wording of which is identical to that in IMO Resolutions and to that in the
relevant ITU-R Recommendations is printed in italics and is prefixed by references (804 etc.) in brackets. When the
text is identical in A.804 and A.806 the reference A.806 will be used.

61097-9 © IEC:1997(E) – 7 –
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61097. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 61097 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60945:1996, Maritime navigation and radiocommunication equipment and systems –
General requirements – Methods of testing and required test results
IEC 61097-3:1994, Global maritime distress and safety system (GMDSS) – Part 3: Digital
selective calling (DSC) equipment – Operational and performance requirements, methods of
testing and required tests results
IEC 61097-8 – Global maritime distress and safety system (GMDSS) – Part 8: Shipborne
watchkeeping receivers for reception of digital selective calling (DSC) in the maritime MF,
MF/HF and UHF bands – Operational and performance requirements, methods of testing and
1)
required test results
IEC 61162-1:1995, Maritime navigation and radiocommunication equipment and systems –
Digital interfaces – Part 1: Single talker and multiple listeners
ISO 3791:1967, Office machines and data processing equipment – Keyboard layouts for
numeric applications
International Convention on Safety of Life at Sea (SOLAS):1974 (as amended), Chapter IV:
Radiocommunications
IMO Resolution A.334(IX):1975, Recommendation on operational standards for radiotelephone
transmitters and receivers
IMO Resolution A.421(XI):1979, Operational standards for radiotelephone alarm signal
generators
IMO Resolution A.694(17):1991, General requirements for shipborne radio equipment forming
part of the global maritime distress and safety system (GMDSS) and for electronic navigational
aids
IMO Resolution A.804(19):1995, Performance standards for shipborne MF radio installations
capable of voice communication and digital selective calling
IMO Resolution A.806(19):1995, Performance standards for shipborne MF/HF radio
installations capable of voice communication, narrow-band direct-printing and digital selective
calling
ITU :1994, Radio Regulations
ITU-R M.493-7:1995, Digital selective-calling system for use in the maritime mobile service
ITU-R M.625-3:1995, Direct-printing telegraph equipment in the maritime mobile service
–––––––––––
1)
To be published.
– 8 – 61097-9 © IEC:1997(E)
ITU-T E.161 (formerly CCITT Recommendation E.161):1988, Arrangement of figures, letters
and symbols on telephones and other devices that can be used for access to a telephone
network
ITU-T V.11:1993, Electrical characteristics for balanced double-current interchange circuits
operating at data signalling rates up to 10 Mbits/s
3 Performance requirements
3.1 Introduction
(806/A1) The MF or MF/HF radiotelephone, narrow band direct printing and digital selective
calling installation, in addition to meeting the requirements of the Radio Regulations, shall
comply with the following performance standards and with the general requirements as set out
in Assembly Resolution A.694(17) as specified in IEC 60945.
(806/A2.1) The installation which may consist of more than one piece of equipment shall be
capable of operating on single-frequency channels or on single- and two-frequency channels.
(806/A2.2) The equipment shall provide for the following categories of calling using both voice
and digital selective calling (DSC):
1 distress, urgency and safety;
2 ship operational requirements; and
3 public correspondence.
(806/A2.3) The equipment shall provide for the following categories of communications using
voice and optionally narrow band direct printing (NBDP) for MF equipment and both for MF/HF
equipment.
(806/A2.4) The equipment shall comprise at least:
1 a transmitter/receiver, including antenna(e);
2 an integral control unit and/or one or more separate control units;
3 a microphone with a press to transmit switch, which may be combined with a telephone in a
handset;
4 an internal or external loudspeaker;
5 an integral or separate narrow band direct printing facility for MF/HF equipment; and
6 an integral or separate digital selective calling facility.
NOTE – (806/A2.4.7) The installation shall also comprise a dedicated DSC watchkeeping facility maintaining a
continuous watch on distress channels only. Where a scanning receiver is employed to watch more than one DSC
distress channel, all selected channels should be scanned within 2 s and the dwell time on each channel shall be
adequate to allow detection of the dot pattern which precedes each DSC call. The scan shall only stop on detection
of a 100 baud dot pattern (see IEC 61097-8).
3.2 Power supplies
(806/A3) The MF or MF/HF radio installation shall be powered from the ship’s main source of
electrical energy. In addition, it shall be possible to operate the MF or MF/HF installation from
an alternative source of electrical energy.

61097-9 © IEC:1997(E) – 9 –
3.3 Control
(806/A4) It shall be possible to conduct distress and safety communications from the position
or in the vicinity of the position, from which the vessel is normally navigated.
3.4 Interfaces
Inputs and outputs applicable to the type of equipment shall be provided as follows:
– Transmitters:
SSB Telephony: – 600 Ω earth free audio input
– Microphone input
– Keying line
DSC and NBDP with analogue interfaces: – 600 Ω earth free audio input
– Keying line
DSC and NBDP with digital interfaces: – ITU-T V.11
– Keying line
– Receivers:
SSB Telephony: – 600 Ω earth free audio output
– Earphone output
– Speaker output
DSC and NBDP with analogue interfaces: – 600 Ω earth free audio output
DSC and NBDP with digital interfaces: – ITU-T V.11
– Control(s):
If a control interface is provided to the equipment it shall meet the requirements of
IEC 61162-1. Other interfaces may be provided in addition. Connection of or failure within
any external circuits shall not degrade the equipment.
3.5 Frequency indication
Radiotelephone frequencies (J3E and H3E) shall be designated in terms of the carrier
frequency; NBDP and DSC frequencies (F1B and J2B) shall be designated in terms of the
assigned (centre) frequency, as defined in the Radio Regulations, and shall be clearly
identifiable on the control panel of the equipment. Independent choice and indication of
transmitting and receiving frequencies shall be possible.
3.6 Distress controls
(806/A2.5) A distress alert shall be activated only by means of a dedicated distress button.
This button shall not be any key of an ITU-T (E.161) digital input panel or an ISO keyboard
(ISO 3791) provided on the equipment.
(806/A2.6) The dedicated distress button shall:
1 be clearly identified; and
2 be protected against inadvertent operation.

– 10 – 61097-9 © IEC:1997(E)
(806/A2.7) The distress alert initiation shall require at least two independent actions.
(806/A2.8) The equipment shall indicate the status of the distress alert transmission.
(806/A2.9) It shall be possible to interrupt and initiate distress alerts at any time.
All adjustments and controls necessary for switching the transmitter and receiver to operate on
the distress and safety channels applicable to the equipment shall be clearly marked in order
that this operation can be performed easily.
3.7 Control panel priority
If the accessible controls are located on a separate control panel and if there are two or more
control panels, one of the control panels shall have priority over the others. If there are two or
more control panels, when any control panel is in use, this shall be clearly indicated on all of
the other control panels.
3.8 Labels
Labels shall be in accordance with IEC 60945.
Those of the following distress frequencies:
DSC Telephony NBDP
(kHz) (kHz) (kHz)
2 187,5 2 182,0 2 174,5
4 207,5 4 125,0 4 177,5
6 312,0 6 215,0 6 268,0
8 414,5 8 291,0 8 376,5
12 577,0 12 290,0 12 520,0
16 804,5 16 420,0 16 695,0
applicable to the equipment, shall be clearly indicated, either on the front panel of the
equipment or on an instruction label supplied with the equipment.
3.9 Safety precautions
3.9.1 Memories
The information in user programmable memory devices shall be protected from interruptions in
the power supply of up to at least 24 h duration. Any software required to facilitate operation in
accordance with this standard shall be permanently installed within the equipment.
Key parameters relating to the equipment and any software necessary for its initial activation or
reactivation shall be stored in solid state non-volatile memory. Facilities shall be provided to
protect all operational software incorporated in the equipment. It shall not be possible during
routine use for the operator to augment, amend or erase any software in the equipment
required for operation in accordance with this standard.
Means shall be provided to monitor the operational software of the equipment automatically at
appropriate regular intervals, and to activate an alarm in the event of failure.

61097-9 © IEC:1997(E) – 11 –
3.10 Classes of emission
The equipment shall provide for the transmission and reception of upper side-band signals
using the classes of emission as appropriate for the equipment:
– J3E: single side-band telephony with the carrier suppressed at least 40 dB below peak
envelope power;
– H3E: single side-band telephony on the frequency 2 182 kHz only with the carrier 4,5 dB to
6 dB below peak envelope power; and
– F1B: frequency shift keying suitable for digital selective calling with a frequency shift of
±85 Hz. (This may be achieved by use of a 1 700 Hz subcarrier. The class of modulation is
then J2B).
The receiver may also provide for the reception of signals of other classes of emission.
3.11 Frequency bands
The equipment shall be capable of operating in either the MF frequency or in the MF and HF
frequency bands.
3.11.1 MF frequency band
The equipment shall provide for the transmission and/or reception in the appropriate
frequencies between 1 605 kHz and 4 000 kHz allocated in the Radio Regulations to the
Maritime Mobile Service.
3.11.2 HF frequency bands
The equipment shall provide for the transmission and/or reception in the appropriate
frequencies in the bands between 4 MHz and 27,5 MHz allocated in the Radio Regulations to
the Maritime Mobile Service.
3.12 Warming-up period
3.12.1 Time
The equipment shall be operational and shall meet the requirements of this standard one
minute after switching on, except as provided in 3.12.2.
3.12.2 Heaters
If the equipment includes parts which require to be heated in order to operate correctly, for
example crystal ovens, then a warming-up period of 30 min from the instant of application of
power to those parts shall be allowed, after which the requirements of this standard shall be
met.
4 Transmitter
4.1 Frequencies and classes of emission
(806/B1.1) The transmitter shall be capable of transmitting on either:
(804/B1.1) a number of frequencies in the bands between 1 605 kHz and 4 000 kHz
considered by the administration as adequate for the operation of the ship, but at least on
the frequencies 2 182 kHz and 2 187,5 kHz,

– 12 – 61097-9 © IEC:1997(E)
or on (806/B1.1) all frequencies allocated to the maritime mobile service in the frequency
band 1 605 kHz to 27 500 kHz. As a minimum, the following frequencies shall be readily
accessible to the operator: the voice frequencies 2 182 kHz, 4 125 kHz, 6 215 kHz,
8 291 kHz, 12 290 kHz and 16 420 kHz; the NBDP frequencies 2 174,5 kHz, 4 177,5 kHz,
6 268 kHz, 8 376,5 kHz, 12 520 kHz and 16 695 kHz; and the DSC frequencies 2 187,5 kHz,
4 207,5 kHz, 6 312 kHz, 8 414,5 kHz, 12 577 kHz and 16 804,5 kHz.
(806/B1.2) Radiotelephone frequencies are designated in terms of the carrier frequency;
NBDP and DSC frequencies are designated in terms of the assigned (centre) frequency. When
NBDP and DSC signals are transmitted using a transmitter in the J2B mode the (suppressed)
carrier frequency shall be adjusted so as to have the NBDP and the DSC signal transmitted on
the assigned frequency. The selected transmitter frequency shall be clearly identifiable on the
control panel of the transmitter.
(806/B1.3) The transmitter shall be capable of transmitting (upper side-band signals, where
appropriate) using classes of emission J3E, H3E and either J2B or F1B.
(806/B1.3.1) When switching to the preset distress frequency 2 182 kHz, the appropriate
class of emission in accordance with the Radio Regulations shall be selected automatically.
(804/B1.3.2) When switching to the preset distress frequency 2 187,5 kHz the class of
emission J2B or F1B shall be selected automatically.
(806/B1.3.2) When switching to the assigned (centre) frequencies for NBDP and DSC classes
of emission F1B or J2B shall be selected automatically.
(806/B1.4) It shall be possible to change the transmitter from any class of emission to another
for which it is designed to operate by means of not more than one control.
(806/B1.5) It shall be possible for the user to select transmission frequencies independent of
any receiver setting. This does not preclude the use of transceivers.
(806/B1.6) It shall be possible to change the transmitter quickly from operation on any
frequency to operation on any other frequency, and in any event within a period not exceeding
15 s. The equipment shall not be able to transmit during channel switching operations.
(806/B1.7) Means shall be provided to prevent over-modulation automatically.
4.2 Frequency accuracy and stability
(806/B2) The transmitted frequency shall remain within 10 Hz of the required frequency at all
times following the warming-up period.
1)
4.3 Output power
(806/B3.1) During normal modulation, the peak envelope power in the case of J3E or H3E
2)
emissions, or the mean power in the case of J2B or F1B emissions, shall be at least 60 W at
any frequency within the specified frequency range.
–––––––––––
1)
In determining the A2 area for MF coast stations an antenna efficiency of 25 % and an output power of 60 W for
ship installations are assumed.
2)
Note should be taken that in some areas of the world a 60 W value may not be adequate to ensure reliable
communications. A value greater than 60 W may be required in these areas.

61097-9 © IEC:1997(E) – 13 –
3)
(806/B3.2) If the rated output power exceeds 400 W in the band, provision shall be made for
reducing the output to 400 W or less (806/B3.2). Generally, only the minimum power necessary
shall be used for all radio communications.
(334/4.2) If the rated output power of the transmitter exceeds 150 W, provision shall be made
for reducing the output power to a value of 60 W or less except for distress frequencies where
the output shall be at least 60 W.
4.4 Transmitter input
For the transmission of voice signals, the transmitter shall have a microphone input, suitable to
produce an output power level within –3 dB and –9 dB relative to full output power when a
sound level of 94 dBA is applied to the microphone.
Additionally an input, earth free, of 600 Ω and 0 dBm shall be provided for analogue signals.
For digital signals, the input shall comply to ITU-T V.11 when provided.
4.5 Permissible warming-up period
(806/B4) The equipment shall be capable of operation within 1 min after switching on.
4.6 Continuous operation
(806/B5) Continuous operation shall be possible when the transmitter is adjusted to operate
at its rated power.
4.7 Controls and indicators
(806/B6.1) Provision shall be made for indicating the antenna current or power delivered to
the antenna. Failure of the indicating system shall not interrupt the antenna circuit.
(806/B6.2) Manually tuned equipment shall be fitted with a sufficient number of indicators to
permit accurate and rapid tuning.
(806/B6.3) Operation of the transmit/receive control shall not cause unwanted emissions.
(806/B6.4) All adjustment and controls necessary for switching the transmitter to operate on
2 182 kHz and 2 187,5 kHz shall be clearly marked in order that these operations may be
performed readily.
4.7.1 Telephony transmit control
In the manual simplex or semi-duplex telephony operating mode, switching from the receiving
condition to the transmitting condition and vice versa, shall be accomplished by a single
control. Any such control shall be located on the microphone or telephone handset and when at
rest shall leave the equipment in the receive condition.
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3)
The Radio Regulations (RR 4357) specify a peak envelope power of 400 W for equipment operating in the MF
band in region 1.
– 14 – 61097-9 © IEC:1997(E)
4.8 Safety precautions
(806/B7) The equipment shall be so designed and constructed that when the transmitter is
providing power to the antenna, the transmitter is protected against damage resulting from
disconnection of the antenna or short-circuiting of antenna terminals. If this protection is
provided by means of a safety device, that device shall automatically be reset following
removal of the antenna open-circuit or short-circuit conditions.
4.9 Power supply
(806/B8.1) If it is necessary to delay the application of voltage, for example anode voltage, to
any part of the transmitter after switching on, this delay shall be provided automatically.
(806/B8.2) If the transmitter includes parts which are required to be heated in order to operate
correctly, for example crystal ovens, the power supplies to the heating circuits shall be so
arranged that they can remain operative when other supplies to or within the equipment are
switched off. If a special switch for the heating circuits is provided, its functions shall be clearly
indicated; it shall normally be in the "on" position and be protected against inadvertent
operation. A visual indication that power is connected to such circuits shall be provided. The
correct operating temperature shall be reached within a period of 30 min after the application of
power.
4.10 Synthesizer lock
It shall not be possible to transmit until any frequency synthesizer is locked.
4.11 Channel switching
It shall not be possible to transmit during transmitter channel switching operations.
4.12 NBDP transmit and receive timing
In the NBDP operating mode switching from the receiving condition to the transmitting
condition and vice versa, added together, shall be completed within 16 ms.
5 Receiver
5.1 Frequencies and classes of emission
(804/C1.1) The receiver shall be capable of either:
(804/C1.1) being tuned throughout the bands between 1 605 kHz and 4 000 kHz. Tuning
shall be either continuous, or incremental steps, or by the selection of a number of spot
frequencies considered by the Administration as adequate for the operation of the ship, or
by any combination of these methods. The frequencies 2 182 kHz and 2 187,5 kHz shall
always be included;
or (806/C1.1) being tuned throughout the bands between 1 605 kHz and 27,5 MHz. Tuning
shall be either continuous, or by incremental steps, or by the selection of a number of spot
frequencies considered by the Administration as adequate for the operation of the ship, or
by any combination of these methods. As a minimum, the following frequencies shall be
readily accessible to the operator: the carrier frequencies 2 182 kHz, 4 125 kHz, 6 215 kHz,
8 291 kHz, 12 290 kHz and 16 420 kHz for radiotelephony; the NBDP frequencies
2 174,5 kHz, 4 177,5 kHz, 6 268 kHz, 8 376,5 kHz, 12 520 kHz and 16 695 kHz; and the
DSC frequencies 2 187,5 kHz, 4 207,5 kHz, 6 312 kHz, 8 414,5 kHz, 12 577 kHz and
16 804,5 kHz.
61097-9 © IEC:1997(E) – 15 –
(806/C1.2) Radiotelephone frequencies shall be designated in terms of the carrier frequency;
NBDP and DSC frequencies shall be designated in terms of the assigned (centre) frequency.
The selected receiver frequency shall be clearly identifiable on the control p
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