SIST EN 60244-11:1999

SLOVENSKI STANDARD
SIST EN 60244-11:1999
01-januar-1999
Methods of measurement for radio transmitters - Part 11: Transposers for FM
sound broadcasting (IEC 60244-11:1989)
Methods of measurement for radio transmitters -- Part 11: Transposers for FM sound
broadcasting
Meßverfahren für Funksender -- Teil 11: Umsetzer für FM-Tonrundfunk
Méthodes de mesure applicables aux émetteurs radioélectriques -- Partie 11:
Réémetteurs pour la radiodiffusion sonore à modulation de fréquence
Ta slovenski standard je istoveten z: EN 60244-11:1993
ICS:
33.060.20 Sprejemna in oddajna Receiving and transmitting
oprema equipment
SIST EN 60244-11:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60244-11:1999

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SIST EN 60244-11:1999

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SIST EN 60244-11:1999

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SIST EN 60244-11:1999

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SIST EN 60244-11:1999

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SIST EN 60244-11:1999
NORME
CEI
INTERNATIONALE
IEC
60244-11
INTERNATIONAL
Première
édition
STANDARD
First edition
1989-01
Méthodes de mesure applicables aux
émetteurs radioélectriques
Onzième partie:
Réémetteurs pour la radiodiffusion sonore
à modulation de fréquence
Methods of measurement for radio transmitters
Part 11:
Transposers for FM sound broadcasting
© IEC 1989 Droits de reproduction réservés —
Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part
of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. 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
CODE PRIX
Commission Electrotechnique Internationale
S
PRICE CODE
International Electrotechnical Commission
IEC
MemayHapoAHaa GneKTpoTexHN4ecnaR HoMHCCHfi
Pour prix, voir catalogue en vigueur
• • For price, see current catalogue

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CONTENTS
Page
FOREWORD 5
PREFACE 5
7
INTRODUCTION
Clause
1. Scope 7
7
2. Object
SECTION ONE - GENERAL CONDITIONS OF OPERATION AND MEASUREMENT
3. Definition 9
4. Input and output signal arrangement 9
9
5. General conditions regarding input signal source and test load
11
6. Terms and definitions for input and output signals
7. General conditions of operation 13
SECTION Two - INPUT AND OUTPUT LEVELS AND GENERAL TRANSPOSER CHARACTERISTICS
8. Input impedance mismatch 13
9. Adjustment and measurement of input levels 13
10. Automatic gain control 13
11. Adjustment and measurement of output power 15
15
12. Frequency
13. Internally generated unwanted signals at the transposer input 17
SECTION THREE - TRANSMISSION PERFORMANCE CHARACTERISTICS
17
14. Amplitude/baseband-frequency characteristic
19
15. Audio-frequency harmonic distortion
16. Harmonic distortion in the coded channels of a stereophonic service 19
17. Crosstalk attenuation (stereophonic separation) 21
21
18. Linear and non-linear crosstalk between A and B channels
23
19. Baseband-frequency intermodulation
25
20. Transmission performance for supplementary services (under consideration)
SECTION FOUR - UNWANTED MODULATION AND SPURIOUS EMISSIONS
25
21. Introduction
Unwanted frequency modulation 25
22.
Unwanted amplitude modulation 29
23.
24. Unwanted modulation in the presence of an interfering input signal 31
25. Unwanted modulation signals in the presence of two interfering input signals 33
26. Spurious emissions in the absence of interfering input signals 33
27. Spurious emissions in the presence of interfering input signals 33
35
28. Changes in performance caused by feedback from output to input
APPENDIX A - Input impedance 39

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
METHODS OF MEASUREMENT
FOR RADIO TRANSMITTERS
Part 11: Transposers for FM sound broadcasting
FOREWORD
1) The formal decisions or agreements of the I EC on technical matters, prepared by Technical Committees on which all the National
Committees having a special interest therein are represented, express, as nearly as possible, an international consensus of opinion
on the subjects dealt with.
2) They have the form of recommendations for international use and they are accepted by the National Committees in that sense.
3) In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the text
of the IEC recommendation for their national rules in so far as national conditions will permit. Any divergence between the
IEC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in the latter.
PREFACE
This standard has been prepared by Sub-Committee 12C: Transmitting equipment, of IEC Technical Committee No. 12:
Radiocommunications.
The text of this standard is based on the following documents:
Six Months' Rule Report on Voting
12C(CO)203 12C(CO)209
Full information on the voting for the approval of this standard can be found in the Voting Report indicated in the table above.
The following IEC Publications are quoted in this standard:
Publications Nos.: 244 : Methods of measurement for radio transmitters.
244-1 (1968) : Part 1: General conditions of measurement, frequency, output power and power con-
sumption.
244-1A (1968) : First supplement: Appendices.
244-2 (1969) : Part 2: Bandwidth, out-of-band power and power of non-essential oscillations.
244-2A (1969) : First supplement: Appendices.
244-2B (1969) : Second supplement: Modulating signals for the measurement of bandwidth and out-of-
band power of transmitters for telephony and sound broadcasting.
244-3 (1972) : Part 3: Wanted and unwanted modulation.
244-3A (1971) : First supplement: Appendices.
244-3B (1972) : Second supplement: Unwanted modulation, including hum and noise modulation.
244-4 (1973) : Part 4: Amplitude/ frequency characteristics and non-linearity distortion in transmitters for
radiotelephony and sound broadcasting.
244-12 (1989) : Guidelines for drawing up descriptive leaflets for transmitters and transposers for sound
and television broadcasting.
487-1 (1984) : Methods of measurement for equipment used in terrestrial radio-relay systems, Part 1:
Measurements common to sub-systems and simulated radio-relay systems.

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METHODS OF MEASUREMENT
FOR RADIO TRANSMITTERS
Part 11: Transposers for FM sound broadcasting
INTRODUCTION
This standard is one of a series of parts of IEC Publication 244, describing recommended methods
of measurement for assessing the performance of radio transmitters.
A number of the existing parts of I E C Publication 244 are currently under review and several of the
older parts will be revised or withdrawn. When this process is complete, the overall publication will
comprise one part dealing with general characteristics, with cross-references to relevant CCIR publications
and the Radio Regulations, and a number of specialist parts, each dealing with a particular type of
transmitter.
This new part, therefore, incorporates all recommended measurements for FM sound broadcasting
transposers in a single publication and supersedes all clauses dealing with FM broadcasting transposers
in the following publications:
Publication 244-2, first edition, 1969
Publication 244-2A, first edition, 1969
Publication 244-2B, first edition, 1969
Publication 244-3, first edition, 1972
Publication 244-3A, first edition, 1971
Publication 244-3B, first edition, 1972
Publication 244-4, first edition, 1973
1. Scope
This standard applies to transposers, as defined in Clause 3, operating in accordance with current
CCIR Recommendation 450 for FM sound broadcasting at VHF, including stereophony. It also
covers requirements for other multiplexed subcarrier services.
2. Object
This standard lays down detailed methods of measurements, selected and recommended for
assessing the essential performance and general characteristics of FM sound broadcasting trans-
posers. It is not mandatory to measure all the defined characteristics. Fewer or additional measure-
ments may be appropriate. Any additional measurements should preferably be in accordance with
relevant standards published by the IEC or by other international bodies.
Limiting values for acceptable performance are not specified, as these are normally given in the
equipment specification, or in requirements laid down by the responsible regulating bodies.
This standard shall be used in conjunction with IEC Publications 244-1 and 244-1A (now being
revised) or, in due course, with the future edition replacing these publications.

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For guidance on the information to be given in descriptive leaflets particular to the type of equip-
ment considered in this standard, refer to the relevant sections of IEC Publication 244-12.
The methods of measurement described in this standard are intended for type tests but they may
also be used for acceptance tests and factory tests. (See IEC Publication 244-1 for the meaning of
these terms.)
SECTION ONE - GENERAL CONDITIONS OF OPERATION
AND MEASUREMENT
Definition
3.
The term "FM sound broadcasting transposer" is used in this standard to refer to that equipment
in an FM sound broadcasting relay station which is connected between the feeder terminations of
the receiving antenna and the transmitting antenna, and in which a frequency transposition is per-
formed without demodulation. The majority of the measurements apply also to a receiver/trans-
mitter combination.
Any device for the suppression of unwanted signals, irrespective of whether or not it is located
inside the transposer, shall be considered to be part of the transposer for the purpose of this
standard.
4. Input and output signal arrangement
For the purpose of measurement, the transposer can be considered in terms of input and output
characteristics, and of transmission performance.
Depending on the particular measurements, one of the three measuring arrangements described
below may be employed. Details of the arrangements are given in Figures 1, 2 and 3.
The modulating signals for the test transmitters in Figures 1 to 3 shall be provided by:
- one or more baseband (audio) signal generators,
- a high quality stereo coder of specified characteristics,
auxiliary devices for the supplementary multiplexed subcarrier services, if required.
-
All measurements concerning transmission performance are carried out with baseband signals at
the output of the test demodulator or, for some stereo tests, at the output of a high quality stereo
decoder.
Because the results of these measurements are critically dependent on the performance of the test
equipment, it is necessary first to check the overall performance of the test equipment in the absence
of the transposer.
5. General conditions regarding input signal source and test load
5.1 Input signal source
The rated load impedance of the test transmitter shall be equal to the nominal input impedance
of the transposer over the whole FM broadcasting band.

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5.2 Test load
The transposer shall be terminated with a test load, the impedance of which, expressed in terms
of return loss relative to the nominal load impedance of the transposer, shall not be less than:
- 26 dB at frequencies within the FM broadcasting band at the output of the transposer.
- 16 dB at frequencies of any measured unwanted frequency outside this band.
5.3 Connection of measuring equipment to the transposer
The preferred arrangement for the test load for low power transposers is an attenuator, the output
of which is used to feed the radio-frequency test equipment.
Alternatively, especially for high power transposers, the test equipment may be connected to the
transposer output through a calibrated directional coupler or suitable matching network inserted
in the line between the transposer and the test load.
Any measuring instruments used at the input of the transposer are connected to the input through
a calibrated directional coupler or suitable matching network inserted in the line between the input
signal source and the transposer.
The terms "connected to the input" and "connected to the output" will hereafter be used for test
equipment connected as described above.
6. Terms and definitions for input and output signals
6.1 Test signals
a) Monophonic signal
The monophonic test input signal is a signal at the appropriate carrier frequency, modulated by
the standard reference audio-frequency (<_ 1 000 Hz), with a specified frequency deviation. If
required, other audio modulation frequencies may be chosen.
b) Stereophonic signal
The stereophonic input test signal is a signal at the appropriate carrier frequency modulated by
a coded stereo (multiplex) signal in accordance with the standard concerned.
The standard reference audio-frequency, <_ 1 000 Hz, shall be applied to both left-hand channel
A and right-hand channel B, or to one of them only, as required for each particular test. The
frequency deviation for each component of the multiplex stereo signal shall be specified and shall
comply with the standard concerned. When required, other audio modulating frequencies may
be chosen.
c) Additional supplementary multiplexed subcarrier services
When required, additional supplementary multiplexed subcarrier services, with specified charac-
teristics, shall be introduced in the test signal.
6.2 Definitions relating to the transposer input signal
a) Input voltage
The r.m.s. voltage of a frequency modulated r.f. carrier at the input of the transposer expressed
in µV or dB(xV).
b) Reference input level
The reference input level for a monophonic or stereophonic input signal is 60 dB(µV), i.e. 1 mV.
c) Input voltage range
The input voltage range of a transposer is the range of input voltage within which the transposer
performance specifications apply.

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6.3 Definitions relating to the output signal
a) Rated output power
When the transposer is operating under specified conditions, its rated output power is the power
of the unmodulated carrier.
b) Reference output level
The reference output level (0 dB) is the level corresponding to rated output power.
7. General conditions of operation
The transposer shall be tested under the following conditions:
a) The measurements shall be made under standard environmental testing conditions (see IEC
Publication 244-1). If required, they shall be repeated for other environmental conditions, in
accordance with the equipment specification.
b) Owing to practical limitations on the siting of receiving and transmitting antennas, there will be
some coupling between them.
Where such coupling is specified, all the transposer tests shall be carried out with this coupling
simulated by feeding part of the output signal to the input terminal of the transposer by means
of directional couplers or resistive pads inserted in the input and output lines of the transposer
(see Figure 1).
Note. - Special measurements concerning transposer instability due to coupling between the input and output are described
in Clause 28.
SECTION TWO - INPUT AND OUTPUT LEVELS AND GENERAL
TRANSPOSER CHARACTERISTICS
8. Input impedance mismatch
The input impedance mismatch is expressed in terms of return loss.
The input impedance mismatch shall be measured over the whole FM broadcasting band
and input voltage range, using any suitable measuring techniques such as those described in
Appendix A.
When an input filter is used, the measurement should be restricted to the pass-band of the transposer.
Note. -
9. Adjustment and measurement of input levels
The required level at the input of the transposer may be obtained directly from a test transmitter
if it is provided with an adjustable and calibrated output. If not, the output of the test transmitter
can be measured with a calibrated spectrum analyser through a calibrated directional coupler
or attenuator. The test signal level is then set to the required value by means of an adjustable
attenuator.
10. Automatic gain control
If the transposer incorporates an adjustable automatic gain control facility, it shall be adjusted
in accordance with the manufacturer's instructions.
Note. - Normally limiters in the FM transposers will ensure constant output power.

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Adjustment and measurement of output power
11.
If the transposer is provided with a control for the adjustment of output power, the output power
shall be set to the rated value for the reference input signal.
The power at the transposer output is measured without modulation using a bolometer, or
calculated by measuring the r.m.s. voltage on the test load.
For any level of the input signal within the input voltage range, the output power of the transposer
shall remain within the specified tolerances.
12. Frequency
This clause concerns the measurement of frequency transposition error and frequency transposi-
tion stability. The terms frequency error and frequency stability (both long-term and short-term
stability) are defined in Clauses 8 and 12 of IEC Publication 244-1.
12.1 Frequency transposition error
The frequency transposition error of a transposer is the error in output frequency when the input
signal frequency is correct.
12.1.1 Test conditions and measuring equipment
a) Arrangement A (Figure 1) is employed, the transposer being adjusted in accordance with Clauses
9, 10 and 11, without modulation.
b) The measurement of frequency shall be made after the warming-up times specified for the
transposer and the measuring equipment have elapsed.
c) Any suitable method for measuring frequency may be used.
12.1.2 Measuring procedure
Either of the following two methods may be used, dependent on the design of the transposer:
a) Frequency transposition error referred to the frequency of the input signal
1. Measure the frequencies of the input and output signals of the transposer simultaneously.
2. Calculate the difference between the two frequencies so measured.
3. Calculate the difference between the specified values of the carrier frequencies at the input
and output of the transposer.
The difference between the values obtained in Items 2 and 3 above, expressed in hertz, is the
4.
frequency transposition error of the transposer.
b) Frequency transposition error referred to the local oscillator frequencies
The transposer may employ either single or double frequency conversion. When, with double
frequency conversion, the two oscillators for the conversion operate in such a way that the
frequency difference between them depends upon a single local oscillator, it is preferable to check
the frequency of this oscillator only.
In all cases, the measurement procedure is as follows:
1. Measure the frequency of the local oscillators simultaneously as in Step 1 of Item a) above.
2. Calculate the difference between the frequencies of the carrier signals at the input and output
of the transposer from the frequency or frequencies so measured.
3. Proceed as in Steps 3 and 4 of Item a) above.

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12.2 Frequency transposition stability
Compliance with any short-term or long-term frequency transposition stability specified for the
transposer can be checked by measuring the frequency transposition error, expressed in hertz, in
accordance with Sub-clause 12.1 above. Frequency transposition stability is the difference between
the highest and the lowest values of frequency transposition error during a stipulated period. The
periods for short-term and long-term stability shall be one hour and six months, respectively.
13. Internally generated unwanted signals at the transposer input
Internally generated unwanted signals at the transposer input may appear in the presence or the
absence of the wanted input signals.
13.1 Test conditions and measuring equipment
a)
Arrangement A (Figure 1) is employed, the transposer being adjusted in accordance with Clauses
9, 10 and 11.
b) A spectrum analyzer is connected to the measurement output of a directional coupler of known
coupling factor, inserted in the appropriate direction, between the input signal source and the
transposer input so that the spectrum analyzer measures only signals from the transposer input.
13.2
Measurement procedure
a) Unwanted signals in the absence of the wanted input signal
1.
From the spectrum analyzer, record the level and frequency of each unwanted component,
ignoring those whose level is less than a specified value.
2. Convert the levels obtained into terms of dB(µW).
b) Unwanted signals in the presence of the wanted input signal
1.
Adjust the level of the unmodulated input signal of the transposer to correspond to the
maximum of the input voltage range.
2. Proceed with Steps 1 and 2 of Item a) above, disregarding the reflected components of the
wanted input signal.
SECTION THREE - TRANSMISSION PERFORMANCE CHARACTERISTICS
14.
Amplitude /baseband-frequency characteristic
The amplitude/baseband-frequency characteristic is the variation with frequency of the ampli-
tude of the demodulated signal, relative to the amplitude at a certain reference frequency, for a
constant value of the frequency deviation of the r.f. input signal.
a)
Arrangement B (Figure 2) is used, the transposer being adjusted in accordance with Clauses 9,
10 and 11.
b)
The baseband frequency generator shall cover the whole baseband frequency range up to 100 kHz
either in steps by manual control or continuously by a sweeping device.
c)
With pre- and de-emphasis switched out, the output of the test demodulator is connected to a
spectrum analyzer or other voltage measuring device.
14.1
Measuring procedure
a) The r.f. signal at the transposer input is adjusted to any specified level within the input voltage
range.

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b) The frequency of the modulating signal is varied, either manually in steps or continuously by
a sweep generator, over the required frequency range, up to 15 kHz for monophony and up to
76 kHz for stereophony, keeping the frequency deviation of the test transmitter constant at a
specified value.
c)
The level of the demodulated signal is measured and recorded as a function of the modulation
frequency. The results shall be expressed in decibels relative to the level at the specified reference
frequency. The input frequency deviation shall also be stated.
15. Audio-frequency harmonic distortion
The harmonic distortion factor is the ratio, expressed in percentage, between (1) the r.m.s. value
of the sum of the second and higher harmonics and (2) the r.m.s. value of the sum of the
fundamental and all harmonics at the demodulator output, for a modulation signal at a given
frequency.
15.1 Test conditions and measuring equipment
a) The test conditions and measuring equipment are as given in Items
a) and b) of Clause 14
above.
b)
The output of the demodulator is connected to a distortion meter having sufficiently wide
bandwidth.
15.2 Measuring procedure
a)
The r.f. signal at the transposer input is adjusted to any specified level within the input voltage
range.
b)
The frequency of the modulating signal is varied manually over a range of from 40 Hz to
7 500 Hz, keeping the frequency deviation of the test transmitter constant at the rated maximum
value.
c)
The distortion of the demodulated signal, expressed as a percentage of the r.m.s. amplitude of
the total output signal, is measured and recorded.
d)
The pre- and de-emphasis filters in the stereo coder and stereo decoder shall be switched out of
circuit.
16. Harmonic distortion in the coded channels of a stereophonic service
16.1
Test conditions and measuring equipment
a)
Arrangement C (Figure 3) is used, the transposer being adjusted in accordance with Clauses 9,
10 and 11.
b)
The audiofrequency generator is connected to one of the two inputs (A or B) of the stereo coder
which supplies the modulating signal to the test transmitter.
c)
The output of the demodulator is connected to the stereo decoder and a distortion meter is
connected to one of the two outputs (A or B) of the decoder.
d)
The pre- and de-emphasis filters in the stereo coder and stereo decoder shall be switched out of
circuit.
16.2
Measuring procedure
a)
The r.f. signal at the transposer input is adjusted to any specified level within the input voltage
range.
b)
With the audio-frequency generator connected to the A input of the stereo coder, the frequency
is varied from 40 Hz to 7
500 Hz, keeping the frequency deviation of the r.f. test transmitter
constant at the rated maximum value.

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With the distortion meter connected to the A output of the stereo decoder, the harmonic
c)
distortion at this output is measured and recorded together with the level of the transposer input
voltage.
The same measuring procedure is repeated for channel B.
d)
attenuation (stereophonic separation)
17. Crosstalk
The crosstalk attenuation is the ratio, expressed in decibels, of the r.m.s. voltage at the output
of the modulated channel to the r.m.s. value of the sum of the linear and non-linear crosstalk
components and the noise at the output of the unmodulated channel.
The minimum value of the crosstalk attenuation for stereophony (stereophonic separation) after
decoding of the multiplex signal shall be measured for the maximum specified frequency deviation.
The stereophonic separation shall be given for both channels, for frequencies within the audio-
frequency band.
Test conditions and measuring equipment
17.1
a) Arrangement C (Figure 3) is used, the transposer being adjusted in accordance with Clauses 9,
10 and 11.
b) The audio-frequency generator is connected to one of the two inputs (A or B) of the stereo coder
which supplies the modulating signal to the test transmitter.
c) The output of the demodulator is connected to the stereo decoder and a voltmeter is connected
successively to the two outputs (A and B) of the decoder.
17.2 Measuring procedure
a) The r.f. signal at the transposer input is adjusted to any specified level within the input voltage
range.
b) With the audio-frequency generator connected to the A input of the stereo coder, the frequency
is varied in steps between 40 Hz and 15 kHz keeping the frequency deviation of the test
transmitter constant at the maximum rated value.
c) For each audio-frequency, the voltage output is measured successively at the A output of the
decoder (wanted output signal) and at the B output (output signal due to crosstalk).
d) The crosstalk is expressed in décibels referred to the wanted channel output.
e)
The same procedure is repeated with the signal applied to the B channel and measuring the
crosstalk in the A channel.
Note. - If required, the linear and non-linear crosstalk can be measured separately as in Clause 18 below.
18.
Linear and non-linear crosstalk between A and B channels
18.1
Linear crosstalk
Linear crosstalk is the ratio expressed in dB of the r.m.s. voltage of a modulating signal of a given
frequency at the output of the modulated channel to the r.m.s. value of the fundamental frequency
crosstalk component at the output of the unmodulated channel.
a) Arrangement C (Figure 3) is used, the transposer being adjusted in accordance with Clauses 9,
10 and 11.
b) The audio-frequency generator is connected to one of the two inputs (A or B) of the stereo coder,
which supplies the modulating signal to the FM test transmitter.
c) The output of the demodulator is connected to the stereo decoder and a spectrum analyzer or
selective voltmeter is connected successively to the two outputs (A and B) of the decoder.

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18.2 Measuring procedure
a)
The r.f. signal at the transposer input is adjusted to any specified level within the input voltage
range.
b) With the audio-frequency generator connected to the A input of the stereo coder, the frequency
is varied in steps between 40
Hz and 15 kHz, keeping the frequency deviation of the r.f. test
transmitter constant at the maximum rated value.
c) For each audio-frequency, the voltage output is measured successively at the A output of the
decoder (wanted output signal) and at the B output (output signal due to crosstalk).
d)
The crosstalk shall be stated in decibels referred to the wanted channel output, together with the
input voltage of the transposer.
e)
The same procedure is repeated, with the signal applied to the B channel and measuring the
crosstalk in the A channel.
18.3 Non-linear crosstalk
Non-linear crosstalk is the ratio expressed in decibels of the r.m.s. voltage of a modulating signal
of a given frequency at the ou
...