ETSI ETS 300 720 ed.1 (1997-03)
Radio Equipment and Systems (RES); Technical characteristics and methods of measurement for UHF on-board communications systems and equipment
Radio Equipment and Systems (RES); Technical characteristics and methods of measurement for UHF on-board communications systems and equipment
DE/RES-01011
Radijska oprema in sistemi (RES) - Tehnične karakteristike in merilne metode za VHF komunikacijske sisteme in naprave za ladijske notranje zveze
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-1999
5DGLMVNDRSUHPDLQVLVWHPL 5(6 7HKQLþQHNDUDNWHULVWLNHLQPHULOQHPHWRGH]D
9+)NRPXQLNDFLMVNHVLVWHPHLQQDSUDYH]DODGLMVNHQRWUDQMH]YH]H
Radio Equipment and Systems (RES); Technical characteristics and methods of
measurement for UHF on-board communications systems and equipment
Ta slovenski standard je istoveten z: ETS 300 720 Edition 1
ICS:
33.060.99 Druga oprema za radijske Other equipment for
komunikacije radiocommunications
47.020.70 Navigacijska in krmilna Navigation and control
oprema equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN ETS 300 720
TELECOMMUNICATION March 1997
STANDARD
Source: ETSI TC-RES Reference: DE/RES-01011
ICS: 33.020
Key words: Maritime, radio
Radio Equipment and Systems (RES);
Technical characteristics and methods of measurement for UHF
on-board communications systems and equipment
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1997. All rights reserved.
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ETS 300 720: March 1997
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.
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ETS 300 720: March 1997
Contents
Foreword .7
1 Scope .9
2 Normative references.9
3 Definitions, abbreviations and symbols.9
3.1 Definitions .9
3.2 Abbreviations .9
3.3 Symbols .9
4 General requirements .9
4.1 Construction.9
4.2 Frequencies .10
4.3 Controls.10
4.4 Switching time.10
4.5 Safety precautions .10
4.6 Class of emission and modulation characteristics.11
4.7 Battery.11
4.8 Loudspeaker and microphone .11
4.9 Labelling.11
4.10 Equipment documentation .11
5 Test conditions, power sources and ambient temperatures .11
5.1 Normal end extreme test conditions .11
5.2 Test power source .11
5.3 Normal test conditions .12
5.3.1 Normal temperature and humidity.12
5.3.2 Normal test voltage .12
5.4 Extreme test conditions .12
5.4.1 Extreme temperatures.12
5.4.1.1 Upper extreme temperature .12
5.4.1.2 Lower extreme temperature .12
5.4.2 Extreme test power supply values.12
5.4.2.1 Upper extreme test voltage .12
5.4.2.2 Lower extreme test voltage .12
5.5 Procedure for tests at extreme temperatures.12
6 General conditions of measurement .13
6.1 Test connections.13
6.2 Arrangements for test signals.13
6.2.1 Test signals applied to the transmitter input.13
6.2.2 Test signals applied to the antenna terminal.13
6.3 Receiver mute or squelch facility .13
6.4 Normal test modulation.13
6.5 Artificial antenna .14
6.6 Test channels .14
6.7 Measurement uncertainty and interpretation of the measuring results.14
6.7.1 Measurement uncertainty.14
6.7.2 Interpretation of the measurement results .14
7 Environmental tests.14
7.1 Procedure .14
7.2 Performance check.15
7.3 Drop test on to a hard surface .15
7.3.1 Definition .15
7.3.2 Method of measurement .15
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ETS 300 720: March 1997
7.3.3 Requirement . 15
7.4 Temperature tests. 16
7.4.1 General . 16
7.4.2 Dry heat . 16
7.4.2.1 Method of measurement. 16
7.4.2.2 Requirement . 16
7.4.3 Damp heat . 16
7.4.3.1 Method of measurement. 16
7.4.3.2 Requirement . 16
8 Transmitter . 17
8.1 Frequency error. 17
8.1.1 Definition. 17
8.1.2 Method of measurement. 17
8.1.3 Limits . 17
8.2 Carrier power. 17
8.2.1 Definition. 17
8.2.2 Method of measurement. 17
8.2.3 Limit . 17
8.3 Frequency deviation . 17
8.3.1 Definition. 17
8.3.2 Maximum frequency deviation. 17
8.3.2.1 Method of measurement. 17
8.3.2.2 Limit. 17
8.3.3 Frequency deviation at modulation frequencies above 3 kHz . 18
8.3.3.1 Method of measurement. 18
8.3.3.2 Limits. 18
8.4 Limitation characteristics of the modulator. 18
8.4.1 Definition. 18
8.4.2 Method of measurement. 18
8.4.3 Limit . 18
8.5 Sensitivity of the modulator, including microphone . 19
8.5.1 Definition. 19
8.5.2 Method of measurement. 19
8.5.3 Limit . 19
8.6 Audio frequency response. 19
8.6.1 Definition. 19
8.6.2 Method of measurement. 19
8.6.3 Limit . 19
8.7 Audio frequency harmonic distortion of the emission. 20
8.7.1 Definition. 20
8.7.2 Method of measurement. 20
8.7.3 Limit . 21
8.8 Adjacent channel power. 21
8.8.1 Definition. 21
8.8.2 Method of measurement. 21
8.8.3 Limit . 21
8.9 Residual modulation of the transmitter. 21
8.9.1 Definition. 21
8.9.2 Method of measurement. 21
8.9.3 Limit . 21
8.10 Transient frequency behaviour of the transmitter. 22
8.10.1 Definition. 22
8.10.2 Method of measurement. 22
8.10.3 Limits . 23
8.11 Conducted spurious emissions conveyed to the antenna. 25
8.11.1 Definition. 25
8.11.2 Method of measurement. 25
8.11.3 Limit . 25
9 Receiver. 25
9.1 Harmonic distortion and rated audio frequency output power. 25
9.1.1 Definition. 25
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ETS 300 720: March 1997
9.1.2 Methods of measurement .25
9.1.3 Limits.26
9.2 Audio frequency response .26
9.2.1 Definition .26
9.2.2 Method of measurement .26
9.2.3 Limits.26
9.3 Maximum usable sensitivity .27
9.3.1 Definition .27
9.3.2 Method of measurement .27
9.3.3 Limits.28
9.4 Co-channel rejection.28
9.4.1 Definition .28
9.4.2 Method of measurement .28
9.4.3 Limit.28
9.5 Adjacent channel selectivity.28
9.5.1 Definition .28
9.5.2 Method of measurement .28
9.5.3 Limits.29
9.6 Spurious response rejection .29
9.6.1 Definition .29
9.6.2 Method of measurement .29
9.6.3 Limit.29
9.7 Intermodulation response .29
9.7.1 Definition .29
9.7.2 Method of measurement .30
9.7.3 Limit.30
9.8 Blocking or desensitisation .30
9.8.1 Definition .30
9.8.2 Method of measurement .30
9.8.3 Limit.30
9.9 Conducted spurious emissions conveyed to the antenna .31
9.9.1 Definition .31
9.9.2 Method of measurement .31
9.9.3 Limit.31
Annex A (normative): Adjacent channel power measurement.32
A.1 Method of measurement .32
A.2 Power measuring receiver specification.32
A.2.1 IF filter.32
A.2.2 Attenuation indicator .34
A.2.3 RMS value indicator.34
A.2.4 Oscillator and amplifier .34
History.35
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ETS 300 720: March 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Radio Equipment and
Systems (RES) Technical Committee of the European Telecommunications Standards Institute (ETSI).
Transposition dates
Date of adoption: 21 February 1997
Date of latest announcement of this ETS (doa): 30 June 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 December 1997
Date of withdrawal of any conflicting National Standard (dow): 31 December 1997
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ETS 300 720: March 1997
1 Scope
This ETS states the minimum technical characteristics required for UHF radio equipment and systems
operating on frequencies allocated to the maritime mobile services by the ITU Radio Regulations,
appendix 20 [1].
2 Normative references
This ETS incorporates by dated or undated reference provisions from other publications. These normative
references are cited at the appropriate places in the text and the publications are listed hereafter. For
dated references subsequent references to, or revisions of any of these publications apply to this ETS
only when incorporated in it by amendment or revision. For undated references, the latest edition of the
publication referred to applies.
[1] ITU Radio Regulations, appendix 20: "Characteristics of equipment used for on-
board communication in the bands between 450 and 470 MHz".
[2] ETR 028: "Radio Equipment and Systems (RES); Uncertainties in the
measurement of mobile radio equipment characteristics".
[3] Recommendation ITU-T P.53 (1988): "Psophometers (apparatus for the
objective measurement of circuit noise)".
[4] Recommendation ISO 694: "Positioning of magnetic compasses in ships".
3 Definitions, abbreviations and symbols
3.1 Definitions
For the purposes of this ETS, the following definition applies:
modulation index: The ratio between the frequency deviation and the modulation frequency.
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
emf electro-motive force
ERP effective radiated power
RF radio frequency
SINAD signal + noise + distortion / noise + distortion
3.3 Symbols
For the purposes of this ETS, the following symbol applies:
-5
dBA acoustic level in dB relative to 2 × 10 Pa
4 General requirements
4.1 Construction
The mechanical and electrical construction and finish of the equipment shall conform in all respects to
good engineering practice and the equipment shall be suitable for use on board ships.
The equipment's colour shall be neither orange nor yellow.
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ETS 300 720: March 1997
4.2 Frequencies
The equipment shall operate either on single-frequency or two-frequency simplex channels on those
frequencies specified in appendix 20 of the Radio Regulations [1].
Table 1: Single frequency simplex channels
Channel designator Frequency
Channel A 467,525 MHz
Channel B 467,550 MHz
Channel C 467,575 MHz
Channel D 457,525 MHz
Channel E 457,550 MHz
Channel F 457,575 MHz
Table 2: Two-frequency simplex channels for use with repeater only
Channel designator Transmit frequency Receive frequency
Channel G 467,525 MHz 457,525 MHz
Channel H 467,550 MHz 457,550 MHz
Channel J 467,575 MHz 457,575 MHz
Independent selection of transmitting and receiving frequencies shall not be possible.
The equipment shall be fitted with at least one single-frequency simplex channel, the frequency of which
shall be 457,525 MHz.
It shall not be possible to transmit during channel-switching operations.
4.3 Controls
The equipment shall have the following controls:
- a channel selector which shall indicate the designator of the channel to which the equipment is set;
- on/off switch for the equipment with visual indication that the equipment is switched on;
- a manual non-locking, push-to-talk switch to operate the transmitter;
- an audio-frequency power volume control.
The user shall not have access to any control which, if wrongly set, might impair the technical
characteristics of the equipment.
4.4 Switching time
The channel switching arrangements shall be such that the time necessary to change over from using one
of the channels to using any other channel does not exceed 5 seconds.
The time necessary to change over from transmission to reception and vice versa, shall not
exceed 0,3 seconds.
4.5 Safety precautions
Provision shall be made for protecting equipment from the effects of excessive current or voltage. Means
shall be incorporated to prevent reversal of polarity of the battery power supply.
Equipment with an antenna socket shall not be damaged by the effect of open-circuit or short-circuit of the
antenna socket for a period of at least 5 minutes.
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ETS 300 720: March 1997
The manufacturer shall declare the compass safe distance according to Recommendation ISO 694 [4],
Method B.
4.6 Class of emission and modulation characteristics
The equipment shall use phase modulation, G3E (frequency modulation with a pre-emphasis of
6 dB/octave).
The equipment shall be designed to operate with a channel spacing of 25 kHz.
4.7 Battery
The battery may be an integral part of the equipment.
Primary and/or secondary batteries may be used.
Provisions shall be made for replacing the battery easily.
If the equipment is fitted with secondary batteries, a suitable battery charger shall be recommended by the
manufacturer.
4.8 Loudspeaker and microphone
The equipment shall be provided with a microphone and a loudspeaker which may be combined.
In the transmit condition the output of the receiver shall be muted.
4.9 Labelling
All controls shall be clearly labelled. The labelling shall include:
- the name of the manufacturer and his trade mark;
- the type number and serial number of the equipment; and
- the compass safe distance.
4.10 Equipment documentation
For the purpose of conformance testing in accordance with this ETS, adequate technical and operational
documentation shall be supplied with the equipment.
5 Test conditions, power sources and ambient temperatures
5.1 Normal end extreme test conditions
Tests shall be made under normal test conditions and also, where stated, under extreme test conditions.
5.2 Test power source
Unless otherwise stated, the battery of the equipment shall be replaced by a test power source capable of
producing normal and extreme test voltages as specified in subclauses 5.3.2 and 5.4.2.
The voltage of the power source shall be measured at the input terminal of the equipment.
During testing, the power source voltage shall be maintained within a tolerance of ±3 % relative to the
voltage level at the beginning of each test.
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5.3 Normal test conditions
5.3.1 Normal temperature and humidity
The normal temperature and humidity conditions for tests shall be a combination of temperature and
humidity within the following limits:
- temperature: +15 °C to +35 °C;
- relative humidity: 20 % to 75 %.
5.3.2 Normal test voltage
The normal test voltage shall be the nominal voltage of the battery as declared by the manufacturer.
5.4 Extreme test conditions
5.4.1 Extreme temperatures
5.4.1.1 Upper extreme temperature
Tests at the upper extreme temperature shall be made at +55 °C.
5.4.1.2 Lower extreme temperature
Tests at the lower extreme temperature shall be made at -20 °C.
5.4.2 Extreme test power supply values
5.4.2.1 Upper extreme test voltage
The upper extreme test voltage shall be declared by the manufacturer and shall not be lower than the
following:
- when using primary batteries, the voltage corresponding to the voltage that a fresh battery gives at
the upper extreme temperature when loaded with a load equal to that of the equipment in the muted
receive condition;
- when using secondary batteries, the voltage corresponding to the voltage that a fully charged
battery gives at the upper extreme temperature when loaded with a load equal to that of the
equipment in the muted receive condition.
5.4.2.2 Lower extreme test voltage
The lower extreme test voltage shall be declared by the manufacturer and shall not be higher than the
following:
- when using primary batteries, 0,85 times the voltage that a fresh battery gives at the lower extreme
temperature when loaded with a load equal to that of the equipment in the muted receive condition;
- when using secondary batteries, 0,85 times the voltage that a fully charged battery gives at the
lower extreme temperature when loaded with a load equal to that of the equipment in the muted
receive condition.
5.5 Procedure for tests at extreme temperatures
The equipment shall be placed in the test chamber at normal temperature. The maximum rate if rising or
reducing the temperature of the chamber shall be 1 °C/minute. The equipment shall be switched off during
the temperature-stabilising periods.
Before conducting tests at extreme temperatures, the equipment in the test chamber shall have reached
thermal equilibrium and be subjected to the extreme temperature for a period of 10 to 16 hours.
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ETS 300 720: March 1997
For tests at the lower extreme temperature, the equipment shall then be switched on to the standby or
receive condition for one minute, after which the relevant tests shall be performed.
For tests at the higher extreme temperature, the equipment shall then be switched on in the high power
transmit condition for half an hour, after which the relevant tests shall be performed.
The temperature of the chamber shall be maintained at the extreme temperatures for the whole duration
of the performance tests.
At the end of the test, and with the equipment still in the chamber, the chamber shall be brought to room
temperature in not less than one hour. The equipment shall then be exposed to normal room temperature
and humidity for not less than three hours or until moisture has dispersed, whichever is the longer, before
the next test is carried out. Alternatively, observing the same precautions, the equipment may be returned
directly to the conditions required for the start of the next tests.
6 General conditions of measurement
6.1 Test connections
For the purpose of testing, suitable connections to the following test points shall be made available:
- the antenna terminal (for 50 Ω connection);
- the transmitter audio input(s);
- the receiver audio output(s);
- the push-to-talk switch;
- the battery terminals for test power source connections.
6.2 Arrangements for test signals
6.2.1 Test signals applied to the transmitter input
For the purpose of tests, the transmitter internal microphone shall be disconnected and an audio
frequency signal generator shall be applied to the transmitter audio input terminals.
6.2.2 Test signals applied to the antenna terminal
Test signal generators shall be connected to the antenna terminal in such a way that the impedance
presented to the receiver input is 50 Ω, irrespective of whether one or more test signals are applied
simultaneously.
The levels of the test signals shall be expressed in terms of the emf.
The effects of any intermodulation product and noise product in the test signal generators should be
negligible.
The nominal frequency of the receiver is the carrier frequency of the selected channel.
6.3 Receiver mute or squelch facility
Unless otherwise specified, the receiver squelch facility shall be made inoperative for the duration of the
tests.
6.4 Normal test modulation
For normal test modulation, the modulation frequency shall be 1 kHz and the frequency deviation shall be
±3 kHz.
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6.5 Artificial antenna
When tests are conducted with an artificial antenna, this shall be a 50 Ω non-reactive, non-radiating load.
6.6 Test channels
For equipment operating in both the 457 MHz and 467 MHz bands, tests shall be carried out at the highest
and lowest channels within the frequency range of the equipment, unless otherwise stated.
6.7 Measurement uncertainty and interpretation of the measuring results
6.7.1 Measurement uncertainty
Table 3: Absolute measurement uncertainties: maximum values
-7
RF frequency ±1 x 10
RF power ±0,75 dB
Maximum frequency deviation:
- within 300 Hz to 6 kHz of audio frequency: ±5 %
- within 6 kHz to 25 kHz of audio frequency: ±3 dB
Deviation limitation ±5 %
Adjacent channel power ±5 dB
Audio output power ±0,5 dB
Amplitude characteristics of receiver limiter ±1,5 dB
Sensitivity at 20 dB SINAD ±3 dB
Two-signal measurement ±4 dB
Three-signal measurement ±3 dB
Radiated emission of transmitter ±6 dB
Radiated emission of receiver ±6 dB
Transmitter transient time ±20 %
Transmitter transient frequency ±250 Hz
For the test methods according to this ETS the uncertainty figures are valid to a confidence level of 95 %
calculated according to the methods described in ETR 028 [2].
6.7.2 Interpretation of the measurement results
The interpretation of the results recorded in a test report for the measurements described in this ETS shall
be as follows:
- the measured value related to the corresponding limit will be used to decide whether an equipment
meets the requirements of this ETS;
- the measurement uncertainty value for the measurement of each parameter shall be included in the
test report;
- the recorded value of the measurement uncertainty shall be, for each measurement, equal to or
lower than the figures in table 3.
7 Environmental tests
7.1 Procedure
Environmental tests shall be carried out before any other tests of the same equipment in respect to the
other requirements of this ETS are performed. The tests shall be carried out in the order they appear in
this ETS.
Unless otherwise stated, the equipment shall be connected to an electrical power source during the
periods for which it is specified that electrical tests shall be carried out. These tests shall be performed
using normal test voltage and on one channel only.
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7.2 Performance check
For the purpose of this ETS, the term "performance check" shall be taken to mean:
- for the transmitter:
- carrier frequency:
- with the transmitter connected to an artificial antenna (see subclause 6.5), the
transmitter shall be keyed without modulation. The carrier frequency shall be within
± 2,3 kHz of the nominal carrier frequency;
- output power:
- with the transmitter connected to an artificial antenna (see subclause 6.5), the
transmitter shall be keyed without modulation. With the output power switch set at
maximum, the output power shall be between 0,4 W and 4 W;
- for the receiver:
- maximum usable sensitivity:
- a test signal at the nominal frequency of the receiver modulated with normal test
modulation (see subclause 6.4) shall be applied to the receiver input. The level of the
input signal shall be adjusted until the SINAD at the output of the receiver is 20 dB and
the output power is at least the rated output power (see subclause 9.1.3). The level of
the input signal shall be less than +12 dBμV.
7.3 Drop test on to a hard surface
7.3.1 Definition
The immunity against the effects of dropping is the ability of the equipment to maintain the specified
mechanical and electrical performance after being subjected to a series of drops on a hard wooden test
surface.
7.3.2 Method of measurement
The hard wooden test surface shall consist of a piece of solid hard wood with a minimum thickness of
15 cm and a mass of 30 kg or more.
The test shall consist of a series of 6 drops, one on each surface of the equipment.
During the test the equipment shall be fitted with a suitable set of batteries and antenna but it shall be
switched off. The test shall be carried out under normal temperature and humidity conditions.
The height of the lowest part of the equipment under test relative to the test surface at the moment of
release shall be 1 m.
If the equipment is to be used with, for example, a separate microphone and/or loudspeaker, the test shall
be carried out for those accessories separately.
Following the test, the equipment shall be subjected to a performance check.
7.3.3 Requirement
The requirement for the performance check shall be met.
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7.4 Temperature tests
7.4.1 General
The maximum rate of raising or reducing the temperature of the chamber in which the equipment is being
tested shall be 1 °C/minute.
7.4.2 Dry heat
7.4.2.1 Method of measurement
The equipment shall be placed in a chamber of normal temperature. The temperature shall then be raised
to and maintained at +70 °C (±3 °C) for a period of at least 10 hours. After this period any climatic control
device provided in the equipment may be switched on and the chamber cooled to 55 °C (±3 °C). The
cooling of the chamber shall be completed within 30 minutes.
The equipment shall then be switched on and shall be kept working continuously for a period of two hours.
The transmitter shall be keyed with a duty cycle of one minute transmission and four minutes reception.
The equipment shall be subjected to a performance check during the two-hour period.
The temperature of the chamber shall be maintained at +55 °C (±3 °C) during the two-hour period.
At the end of the test, and with the equipment still in the chamber, the chamber shall be brought to room
temperature in not less than one hour. The equipment shall then be exposed to normal room temperature
and humidity for not less than three hours before the next test is carried out.
7.4.2.2 Requirement
The requirement for the performance check shall be met.
7.4.3 Damp heat
7.4.3.1 Method of measurement
The equipment shall be placed in a chamber at normal room temperature and humidity which, steadily,
over a period three hours (±30 minutes), shall be heated from room temperature to +40 °C (± 3°C) and
shall during this period be brought to a relative humidity of 93 % (±2 %) so that excessive condensation is
avoided.
30 minutes later the equipment shall be switched on, and shall then be kept working continuously for a
period of two hours. The transmitter shall be keyed with a duty cycle of one minute transmission and four
minutes reception.
The equipment shall be subjected to a performance check during the two-hour period.
The temperature and relative humidity of the chamber shall be maintained at +40 °C ± 3 °C and
93 % ± 2 % during the two-hour, 30 minutes period.
At the end of the test, and with the equipment still in the chamber, the chamber shall be brought to room
temperature in not less than one hour. The equipment shall then be exposed to normal room temperature
and humidity for not less than three hours, or until moisture has dispersed, whichever is longer, before the
next test is carried out.
7.4.3.2 Requirement
The requirement for the performance check shall be met.
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ETS 300 720: March 1997
8 Transmitter
8.1 Frequency error
8.1.1 Definition
The frequency error is the difference between the measured carrier frequency and its nominal value.
8.1.2 Method of measurement
The carrier frequency shall be measured in the absence of modulation, with the transmitter connected to
an artificial antenna (see subclause 6.5). Measurements shall be made under normal test conditions (see
subclause 5.3) and under extreme test conditions (subclauses 5.4.1 and 5.4.2 applied simultaneously).
8.1.3 Limits
The frequency error shall not exceed 2,3 kHz.
8.2 Carrier power
8.2.1 Definition
The carrier power is the mean power delivered to the artificial antenna during one radio frequency cycle in
the absence of modulation.
8.2.2 Method of measurement
The transmitter shall be connected to an artificial antenna (see subclause 6.5) and the power delivered to
this artificial antenna shall be measured. The measurements shall be made under normal test conditions
(see subclause 5.3) and under extreme test conditions (subclauses 5.4.1 and 5.4.2 applied
simultaneously).
If an output power switch is fitted it shall be placed in the maximum position.
8.2.3 Limit
The carrier power shall not exceed 4 W.
8.3 Frequency deviation
8.3.1 Definition
The frequency deviation is the difference between the instantaneous frequency of the modulated radio
frequency signal and the carrier frequency in the absence of modulation.
8.3.2 Maximum frequency deviation
8.3.2.1 Method of measurement
The frequency deviation shall be measured at the output with the transmitter connected to an artificial
antenna (see subclause 6.5), by means of a deviation meter capable of measuring the maximum
deviation, including that due to any harmonics and intermodulation products which may be generated in
the transmitter.
The modulation frequency shall be varied between 100 Hz and 3 kHz. The level of this test signal shall be
20 dB above the level which produces normal test modulation (see subclause 6.4). This test shall be
carried out with the output power switch set at maximum and then at minimum.
8.3.2.2 Limit
The maximum frequency deviation shall not exceed ±5 kHz.
- 14 dB/octave - 14 dB/octave
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ETS 300 720: March 1997
8.3.3 Frequency deviation at modulation frequencies above 3 kHz
8.3.3.1 Method of measurement
The transmitter shall operate under normal test conditions (see subclause 5.3) connected to a load as
specified in subclause 6.5. The transmitter shall be modulated by the normal test modulation (see
subclause 6.4). With the input level of the modulating signal being kept constant, the modulation
frequency shall be varied between 3 kHz and 25 kHz and the frequency deviation shall be measured.
8.3.3.2 Limits
For modulation frequencies between 3 kHz and 6 kHz the frequency deviation shall not exceed the
frequency deviation with a modulation frequency of 3 kHz. For a modulation frequency of 6 kHz, the
frequency deviation shall not exceed ±1,5 kHz, as shown in figure 1.
For modulation frequencies between 6 kHz and 25 kHz, the frequency deviation shall not exceed that
given by a linear response of frequency deviation (in dB) against modulation frequency, starting at the
point where the modulation frequency is 6 kHz and the frequency deviation is ±1,5 kHz and inclined at
14 dB per octave, with the frequency deviation diminishing as the modulation frequency increases, as
shown in figure 1.
± 5 kH z
m easured
x
at 3 kHz
x
± 1,5 kH z
0 300 Hz 3 kHz 6 kHz
25 kHz
Audio frequency
Figure 1: Frequency deviation versus audio modulation frequency
8.4 Limitation characteristics of the modulator
8.4.1 Definition
This characteristic expresses the capability of the transmitter of being modulated with a deviation
approaching the maximum deviation specified in subclause 8.3.2.
8.4.2 Method of measurement
A modulating signal at a frequency of 1 kHz shall be applied to the transmitter, and its level adjusted so
that the frequency deviation is ±1 kHz. The level of the modulating signal shall then be increased by 20 dB
and the dev
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