SIST EN 60315-4:1999

Methods of measurement on radio receivers for various classes of emission -- Part 4: Receivers for frequency-modulated sound broadcasting emissions

Applies to radio receives and tuners for the reception of frequency- modulated sound-broadcasting emissions with rated maximum system deviations of ±75 kHz and ±50 kHz in ITU Band 8. Deals mainly with methods of measurement using radiofrequency signals applied to the antenna terminals of the receiver.

Meßverfahren für Funkempfänger für verschiedene Sendearten -- Teil 4: Empfänger für frequenzmodulierte Ton-Rundfunksendungen

Méthodes de mesure applicables aux récepteurs radioélectriques pour diverses classes d'émission -- Partie 4: Récepteurs pour émissions de radiodiffusion en modulation de fréquence

S'applique aux récepteurs radio et aux syntoniseurs destinés à la réception des émissions de radiodiffusion en modulation de fréquence, ayant des excursions maximales nominales du système de ±75 kHz et de ±50 dans la bande 8 de l'UIT. Traite principalement des méthodes de mesure utilisant des signaux RF appliqués aux bornes d'antenne du récepteur.

Methods of measurement on radio receivers for various classes of emission -- Part 4: Receivers for frequency-modulated sound broadcasting emissions (IEC 60315-4:1997)

General Information

• Status: Published
• Publication Date: 31-Mar-1999
• ICS: 33.160.20 - Radio receivers
• Technical Committee: AVM - Audio, video and multimedia systems and equipment
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-1999
• Due Date: 01-Apr-1999
• Completion Date: 01-Apr-1999
• Ref Project: EN 60315-4:1998 - Methods of measurement on radio receivers for various classes of emission - Part 4: Receivers for frequency-modulated sound broadcasting emissions

Relations

• Amended By: SIST EN 60315-4:1999/oprA1:2025 - Methods of measurement on radio receivers for various classes of emission - Part 4: Receivers for frequency-modulated sound broadcasting emissions
• Effective Date: 10-Oct-2023

Overview

EN 60315-4:1998 (identical to IEC 60315-4:1997) defines methods of measurement for FM radio receivers and tuners intended for frequency‑modulated sound broadcasting. The standard applies to receivers with rated maximum system deviations of ±75 kHz and ±50 kHz in ITU Band 8 and focuses on measurements made using radio‑frequency signals applied to the antenna terminals. It standardizes test conditions and measurement procedures to enable reproducible, comparable results across test laboratories and manufacturers. Note: the standard specifies measurement methods but does not set performance limits.

Key Topics

The document covers a comprehensive set of receiver characteristics and measurement methods, including:

• Sensitivity and internal noise: signal‑to‑noise ratio (weighted/unweighted), SINAD, noise‑limited and gain‑limited sensitivity, usable and deviation sensitivity.
• Rejection of unwanted signals: capture ratio, selectivity, nearby‑channel rejection, image and IF rejection, spurious responses, suppression of amplitude modulation and intermodulation products.
• Interference from internal sources: oscillations, hum and acoustic feedback.
• Overall audio‑frequency characteristics: fidelity, harmonic and intermodulation distortion, crosstalk, residual output and frequency response.
• Effects of additional modulations: handling of SCA signals, RDS interference measurement and suppression of pilot/subcarrier artifacts.
• Antenna‑related measurements: sensitivity, antenna gain and directional response for rod/telescopic or built‑in antennas (including methods using an absorbing clamp).
• Measurement infrastructure and figures: test arrangements, weighting filters, antenna substitution networks and annexed examples (band‑elimination filters, clamp corrections).

Applications

EN 60315-4:1998 is used by:

• Receiver manufacturers for design verification, R&D and production test development.
• Test laboratories and certification bodies to perform repeatable, comparable measurements on FM tuners and receivers.
• Product engineers and compliance teams to characterize sensitivity, selectivity, distortion and susceptibility to adjacent‑channel and RDS interference.
• Quality assurance teams benchmarking receiver performance and aiding troubleshooting during product development.

Practical outcomes include robust measurement of SINAD, capture ratio, selectivity curves, audio fidelity and RDS‑related interference - essential metrics for FM receiver design and market comparison.

Related Standards

• IEC/EN 60315-1 (general measurement methods)
• IEC/EN 60315 series (Parts 3, 7, 9)
• CISPR 16-1 (measurement apparatus)
• CISPR 20 (immunity limits for receivers)
• ITU‑R recommendations (e.g., Rec. 468)

Keywords: EN 60315-4:1998, IEC 60315-4, FM receivers, frequency‑modulated sound broadcasting, measurement methods, sensitivity, selectivity, SINAD, ITU Band 8, antenna input, RDS.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-1999
Methods of measurement on radio receivers for various classes of emission -- Part
4: Receivers for frequency-modulated sound broadcasting emissions (IEC 60315-
4:1997)
Methods of measurement on radio receivers for various classes of emission -- Part 4:
Receivers for frequency-modulated sound broadcasting emissions
Meßverfahren für Funkempfänger für verschiedene Sendearten -- Teil 4: Empfänger für
frequenzmodulierte Ton-Rundfunksendungen
Méthodes de mesure applicables aux récepteurs radioélectriques pour diverses classes
d'émission -- Partie 4: Récepteurs pour émissions de radiodiffusion en modulation de
fréquence
Ta slovenski standard je istoveten z: EN 60315-4:1998
ICS:
33.160.20 Radijski sprejemniki Radio receivers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
60315-4
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1997-11
Méthodes de mesure applicables aux récepteurs
radioélectriques pour diverses classes d'émission –
Partie 4:
Récepteurs pour émissions de radiodiffusion
en modulation de fréquence
Methods of measurement on radio receivers for
various classes of emission –
Part 4:
Receivers for frequency-modulated
sound broadcasting emissions
 IEC 1997 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
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procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
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Telefax: [phone] e-mail: [e-mail] IEC web site http: //www.iec.ch
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Pour prix, voir catalogue en vigueur
For price, see current catalogue

60315-4 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 9
Clause
1 General. 13
1.1 Scope. 13
1.2 Normative references. 13
1.3 Definitions. 15
1.4 Standard measuring conditions . 17
1.5 General notes on measurements. 27
2 Sensitivity and internal noise. 33
2.1 Explanation of terms . 33
2.2 Signal-to-noise ratio (weighted and unweighted) and SINAD . 33
2.3 Noise-limited sensitivity. 35
2.4 Gain-limited sensitivity. 37
2.5 Usable sensitivity. 37
2.6 Deviation sensitivity. 39
2.7 Input-output characteristics. 39
3 Rejection of unwanted signals. 41
3.1 Capture ratio. 41
3.2 Selectivity and nearby channel rejection (two-signal) . 43
3.3 Rejection of intermediate and image frequencies, and spurious responses . 47
3.4 Suppression of amplitude modulation . 53
3.5 Rejection of r.f. signal intermodulation products . 55
3.6 Tuning and automatic frequency control (AFC) characteristics . 63
4 Interference due to internal sources . 65
4.1 Single-signal whistles. 65
4.2 Modulation hum (interference at power supply frequency). 65
4.3 Unwanted self-oscillations. 67
4.4 Acoustic feedback. 69

60315-4 © IEC:1997 – 5 –
Page
5 Overall audio-frequency characteristics. 69
5.1 Fidelity. 69
5.2 Harmonic distortion. 71
5.3 Intermodulation distortion. 79
5.4 Inter-channel characteristics. 81
5.5 Characteristics of the volume control. 83
5.6 Residual output. 85
5.7 Crosstalk attenuation. 85
5.8 Overall audio-frequency response . 87
6 Effect of additional modulations of the input signal . 89
6.1 Rejection of signals in the ranges 16 kHz to 22 kHz and 54 kHz to 99 kHz. 89
6.2 Rejection of signals in the range 62 kHz to 73 kHz (SCA rejection) . 89
6.3 Measurement of interference caused by RDS signals . 89
6.4 Suppression of the fundamental, harmonics and sidebands of the subcarrier
and the pilot-tone signal . 91
6.5 Suppression of interference due to adjacent channel signals with a
stereophonic receiver using the pilot-tone system. 93
7 Sensitivity, antenna gain and directional response of receivers using rod, telescopic
or built-in antennas . 93
7.1 Introduction. 93
7.2 Method of measurement of sensitivity and antenna gain for a receiver using
a rod or telescopic antenna by the absorbing clamp described in CISPR 16-1. 93
8 Characteristics whose methods of measurement are specified in IEC 60315-1 . 95
8.1 Introduction. 95
8.2 List of characteristics and cross-references. 95
Figures
1 Frequency response limits of band-pass filter 200 Hz to 15 kHz . 97
2 Frequency response limits of band-pass filter 22,4 Hz to 15 kHz . 99
3 Frequency response limits of band-pass filter 200 Hz to 1,5 kHz . 99
4 Frequency response limits of the 1 kHz band-elimination filter. 101
5 Weighting filter for converting white noise into special coloured noise for
selectivity measurements. 101
6 Arrangement for various measurements with two r.f. input signals . 103
7 Antenna substitution networks for injecting one or two signals, for 50 Ω signal
generators and 75 Ω unbalanced and 300 Ω balanced receiver inputs . 105
8 Arrangement for various measurements with one r.f. input signal . 107
9 Signal-to-noise ratio. 109

60315-4 © IEC:1997 – 7 –
Page
10 Noise-limited sensitivity as a function of signal frequency. 109
11 Gain-limited sensitivity as a function of signal frequency . 111
12 Output/input characteristics and noise output curves showing terms defined in 1.3 . 113
13 Capture ratio . 115
14 Selectivity curves. 117
15 Image and intermediate frequency rejection ratios. 119
16 Spurious responses at a tuning frequency of 94 MHz (single signal method). 121
17 Arrangement for measuring rejection of unwanted signals simulating cable reception,
using sinusoidal modulation . 123
18 Arrangement for various measurements using three r.f. input signals . 125
19 Tuning characteristics. 127
20 Tuning characteristics obtained by measuring the local oscillator frequency . 127
21 Measurement of acoustic feedback . 129
22 Arrangement for measuring fidelity. 129
23 Overall total harmonic distortion as a function of a.f. output power . 131
24 Distortion-limited output power as a function of modulation frequency . 131
25 Total harmonic distortion as a function of r.f. input signal level . 133
26 Total harmonic distortion as a function of the deviation . 133
27 Variation of distortion with detuning. 135
28 Total harmonic distortion as a function of the a.f. modulation frequency . 135
29 Cross-intermodulation between the channels of a stereo receiver (pilot-tone system) . 137
A.1 Example of a passive 1 kHz band-elimination filter capable of meeting the limits
shown in figure 4 . 139
D.1 Arrangement for r.f. signal injection into the antenna with an absorbing clamp. 147
D.2 Correction curves for the insertion loss of the absorbing clamp . 147
Annexes
A Example of a 1 kHz band-elimination filter. 139
B Standard deviations for supplementary services. 141
C Measurement of crosstalk between stereo channels. 143
D Characteristics of rod and telescopic antennas (under consideration) . 145

60315-4 © IEC:1997 – 9 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
METHODS OF MEASUREMENT ON RADIO RECEIVERS FOR
VARIOUS CLASSES OF EMISSION –
Part 4: Receivers for frequency-modulated
sound broadcasting emissions
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 60315-4 has been prepared by IEC subcommittee 100A: Multimedia
end-user equipment, of IEC technical committee 100: Audio, video and multimedia systems and
equipment.
This second edition cancels and replaces the first edition published in 1982 and constitutes a
technical revision.
This part of IEC 60315 shall be read in conjunction with IEC 60315-1.
The text of this standard is based on the following documents:
FDIS Report on voting
100A/58/FDIS 100A/60/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, C and D are for information only.

60315-4 © IEC:1997 – 11 –
IEC 60315 consists of the following parts under the general title: Methods of measurement on
radio receivers for various classes of emission:
– Part 1: 1988, General considerations and methods of measurement, including audio-
frequency measurements
– Part 3: 1989, Receivers for amplitude – modulated sound broadcasting emissions
– Part 4: 1997, Receivers for frequency – modulated sound broadcasting emissions
– Part 5: 1971, Specialized radio-frequency measurements – Measurement on frequency-
modulated receivers of the response to impulsive interference
– Part 6: 1991, General purpose communication receivers
– Part 7: 1995, Methods of measurement on digital satellite radio (DSR) receivers
– Part 8: 1975, Radio-frequency measurements on professional receivers for frequency-
modulated telegraphy systems
– Part 9: 1996, Measurement of the characteristics relevant to radio data system (RDS)
reception
60315-4 © IEC:1997 – 13 –
METHODS OF MEASUREMENT ON RADIO RECEIVERS FOR
VARIOUS CLASSES OF EMISSION –
Part 4: Receivers for frequency-modulated
sound broadcasting emissions
1 General
1.1 Scope
This part of IEC 60315 applies to radio receivers and tuners for the reception of frequency-
modulated sound-broadcasting emissions with rated maximum system deviations of ±75 kHz
and ±50 kHz in ITU Band 8. It deals mainly with methods of measurement using radio-
frequency signals applied to the antenna terminals of the receiver. The measurements and
specified conditions of test are selected to permit the comparison of results obtained by
different observers and on other receivers. Performance requirements are not specified in
this standard.
Radiation and immunity tests and requirements are not included since these are described in
CISPR 13 and CISPR 20.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 60315. 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 60315 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 60098: 1987, Analogue audio disk records and reproducing equipment
IEC 60268-1: 1985, Sound system equipment – Part 1: General
IEC 60268-3: 1988, Sound system equipment – Part 3: Amplifiers
IEC 60315-1: 1988, Methods of measurement on radio receivers for various classes of
emission – Part 1: General considerations and methods of measurement, including audio-
frequency measurements
IEC 60315-3: 1989, Methods of measurement on radio receivers for various classes of
emission – Part 3: Receiver for amplitude-modulated sound-broadcasting emissions
IEC 60315-7: 1995, Methods of measurement on radio receivers for various classes of
emission – Part 7: Methods of measurement on digital satellite radio (DSR) receivers
IEC 60315-9: 1996, Methods of measurement on radio receivers for various class of emission –
Part 9: Measurement of the characteristics relevant to Radio Data System (RDS) reception
IEC 60651: 1979, Sound level meters
IEC 61260: 1995, Electroacoustics – Octave-band and fractional-octave-band filters
CISPR 16-1: 1993, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 1: Radio disturbance and immunity measuring apparatus

60315-4 © IEC:1997 – 15 –
CISPR 20: 1996, Limits and methods of measurement of immunity characteristics of sound and
television broadcast receivers and associated equipment
ITU-R Recommendation 468-4: 1990: Measurement of audio-frequency
ITU-R Recommendation 559-2: 1990: Objective measurement of radio-frequency protection
ratios in LF, MF and HF broadcasting
1.3 Definitions
For the purposes of this part of IEC 60315, the following definitions apply.
1.3.1
carrier frequency
the mean value of the instantaneous frequency or the frequency generated in the absence of
modulation. With a perfect modulation system in which no d.c. component and no non-linear
distortion are involved, the two values are the same
1.3.2
instantaneous frequency deviation
the difference between the instantaneous frequency of the modulated radio-frequency signal
and the carrier frequency
1.3.3
peak frequency deviation
the peak value of the instantaneous frequency deviation
1.3.4
peak-to-peak deviation
twice the peak frequency deviation
NOTE 1 – To avoid confusion between "peak frequency deviation" and "peak-to-peak frequency deviation", peak-to-
peak deviation is expressed as, for example, ± 50 kHz.
NOTE 2 – "Peak-to-peak frequency deviation" is generally abbreviated to "deviation" in this standard.
1.3.5
rated maximum system deviation
the maximum peak-to-peak frequency deviation (see 1.3.4) specified for the system under
consideration
1.3.6
modulation factor
the ratio of the peak-to-peak deviation of the signal to the rated maximum system deviation,
usually expressed as a percentage
NOTE – This definition arises by direct analogy with the case of amplitude modulation.
1.3.7
–3 dB limiting level
the input signal level at which the audio-frequency output voltage level is 3 dB below the value
at a specified high r.f. input signal level, preferably 80 dB(fW)
1.3.8
amplification reserve
the attenuation in decibels of the volume control when adjusted to produce rated (distortion-limited)
output voltage or power, with a specified high r.f. input signal level, preferably 80 dB(fW)
NOTE – This characteristic is undefined for a receiver or tuner without a volume control.

60315-4 © IEC:1997 – 17 –
1.3.9
deviation sensitivity
the value of deviation required to produce rated (distortion-limited) output voltage or power
with the volume control set at maximum and a specified high r.f. input signal level, preferably
80 dB(fW)
1.3.10
ultimate signal-to-noise ratio
the value of signal-to-noise ratio for r.f. input signal levels sufficiently high that no further
increase in signal-to-noise ratio occurs when the input signal level is increased
1.3.11
stereo threshold
the r.f. input signal level at which the stereo decoder begins to operate
NOTE – A marked decrease in signal-to-noise ratio is usual at this signal level unless signal-strength dependent
cross-talk circuits are included.
1.3.12
stereo indicator threshold
the input signal level at which the visual indicator shows that the receiver is operating in the
stereo mode
NOTE – This level may or may not be identical to the stereo threshold.
1.3.13
muting threshold
the input signal level at which the muting circuits allow the a.f. output signal to appear at the
output terminals
NOTE – The threshold may be different for increasing and decreasing signal levels. This hysteresis is usually
intentional as it prevents unsatisfactory operation with r.f. input signals at or near the threshold level.
1.3.14
muting attenuation
the reduction in a.f. output, selectively measured at 1 kHz, due to an input signal modulated
at 1 kHz at rated maximum system deviation, when muting occurs
1.3.15
50 dB quieting sensitivity
the r.f. input signal level at which an increase in a.f. output of 50 dB occurs under defined
conditions (see 2.3) when the modulation is changed from none (except the pilot-tone if the
measurement is to be made in stereo mode) to the standard value of deviation (see 1.4.2.1)
1.4 Standard measuring conditions
1.4.1 Measurements at audio-frequency output terminals
1.4.1.1 Standard audio-frequency output level
Standard audio-frequency output level is the reference output level for audio-frequency
measurements and shall be 10 dB below the rated output voltage or power. Alternatively, a
stated value of output voltage or power selected from 500 mV, 1 W, 500 mW, 50 mW, 5 mW
or 1 mW may be used (see IEC 60315-1).

60315-4 © IEC:1997 – 19 –
1.4.1.2 Audio-frequency substitute load
The audio-frequency substitute load is a stated physical (usually resistive) impedance for
terminating audio-output terminals, (see IEC 60315-1).
1.4.1.3 Audio-frequency filters
When making measurements at audio-frequency output terminals, unless it is specifically
intended to measure low audio-frequency and ultrasonic components in the output voltage, it is
desirable to interpose a band-pass filter between the output terminals and the measuring
instrument. To allow the use of practicable impedances in this filter the substitute load shall be
connected directly to the audio-frequency output terminals. If the filter has significant insertion
loss this shall be allowed for when determining the results.
It is advisable to use the same filter for both monophonic and stereophonic receivers. This filter
prevents errors due to the presence of pilot-tone or subcarrier components in the receiver
output. The pass-band of this filter shall be 200 Hz to 15 kHz, for which frequencies the
attenuation relative to that at 1 kHz shall not exceed 3 dB. Below 200 Hz the attenuation slope
shall tend to at least 18 dB/octave. At 19 kHz the attenuation shall be at least 50 dB, and above
19 kHz it shall be at least 30 dB (see figure 1). This filter usually prevents the results of
measurements from being affected by hum.
Filters for octave and third-octave band measurements shall comply with the requirements
of IEC 61260.
Table 1 lists the audio-frequency filters which are used in measurements in this standard.
Table 1 – Audio-frequency filters
Type of filter Figure Reference Notes
200 Hz – 15 kHz band-pass 1 1.4.1.3 With 19 kHz notch
22,4 Hz – 15 kHz band-pass 2 2.2.1 With 19 kHz notch
200 Hz – 1,5 kHz band-pass 3 Figure 8 With 19 kHz notch
15 kHz low-pass None 1.4.2.3 60 dB/octave attenuation slope
1 kHz band-stop 4 Figure 8 See also annex A
1 kHz band-pass None Figure 6 / -octave: IEC 61260
A-weighting None Figure 8 See IEC 60651
Weighting filter for measurement Annex A of 2.2.1 Consistent with ITU-R
of noise IEC 60315-1 Recommendation 468-4
Weighting filter for coloured noise 5 1.4.2.3 Consistent with ITU-R
Recommendation 559-2
1.4.2 Radio-frequency signal(s)
1.4.2.1 Standard value of deviation
The standard value of deviation for measurements shall be the rated maximum system
deviation (RMSD) given in table 2. The deviation shall be stated with the results.
Measurements at lower deviations are useful in some cases: where these are carried out the
deviation used shall be stated with the results.

60315-4 © IEC:1997 – 21 –
Table 2 – Standard values of deviation
Mode/signal RMSD ±50 kHz RMSD ±75 kHz
Mono ±50 kHz ±75 kHz
Stereo ±45 kHz ±67,5 kHz
Pilot-tone ±4,5 kHz ±6,75 kHz
NOTE 1 – Where a single value for deviation is stated in the text, it applies to a system with RMSD = ±75 kHz.
For a system with RMSD = ±50 kHz, the stated value is reduced in proportion. In some cases, the value
for RMSD = ±50 kHz is given in parentheses: for example, (±50 kHz).
NOTE 2 – The deviations for supplementary services (such as SCA, RDS and ARI), which may vary in
different ITU regions or countries, are given in annex B.
1.4.2.2 Standard modulating frequency
The standard modulating frequency shall be the standard reference frequency (1 000 Hz).
When required, other frequencies may be chosen, if possible, from the one-third octave band
centre frequencies given in table I of IEC 60315-1.
1.4.2.3 Standard modulation using coloured noise
The noise weighting is chosen so that the spectrum of the noise resembles that of modern
(western European) dance music, which is a particularly critical form of modulation in the case
of adjacent channel interference.
The noise signal is obtained from a Gaussian white noise generator by passing the signal
through a weighting filter as specified in figure 5, followed by a low-pass filter with a cut-off
frequency of 15 kHz and a slope of 60 dB/octave, and then through a pre-emphasis network
(50 μs or 75 μs as appropriate).
The audio-frequency amplitude versus frequency characteristic of the modulation stage of the
signal generator should not vary by more than 2 dB up to the cut-off frequency of the low-pass
filter.
The accuracy of the measurement depends very much on the precision with which the
frequency deviation of the signal generators can be set; this is especially true for the unwanted
transmitter. The line-up procedure therefore should be carried out very carefully.
The deviation of the signal shall be adjusted by means of the arrangement shown in figure 6.
The meter V shall be a quasi-peak voltmeter (see annex A of IEC 60315-1). To obtain
the required deviation conditions, the switch S is placed in position 1 and the modulation
at 500 Hz from the audio-frequency generator adjusted to ±32 kHz (±21,3 kHz) deviation. The
meter reading is noted. The switch S is then placed in position 2 and the noise modulation
adjusted to give the same reading on the quasi-peak meter.
NOTE – The deviation with 500 Hz modulation should be checked with a deviation meter unless the deviation
meter, if any, included in the signal generator is known to be accurate.
1.4.2.4 Standard modulating signal
This is the base-band signal with standard modulating frequency (see 1.4.2.2) and standard
value of deviation (see 1.4.2.1). In case of stereophonic mode measurements, a pilot tone
signal with the standard deviation shall be included.

60315-4 © IEC:1997 – 23 –
1.4.2.5 Standard carrier frequencies
The standard carrier frequency depends on the frequency allocation(s) for f.m. broadcasting in
the region where the receiver is to be used. Receivers within the scope of this standard usually
cover the bands given in table 3. For these bands, the standard measuring frequencies are
shown in the table.
Table 3 – Standard measuring frequencies
Band coverage MHz Standard measuring frequency
MHz
65,8 to 73,0 69
76,0 to 90,0 83
87,5 to 104,0 94
87,5 to 108,0 98
1.4.2.6 Standard radio-frequency test signal
The standard radio-frequency test signal is a signal at the appropriate standard carrier
frequency (see 1.4.2.5), modulated with the standard modulating signal (see 1.4.2.4). The
available power from the source, at the receiver antenna terminals, shall be 70 dB(fW) (equal
to 40 dB(pW)).
1.4.2.7 Standard radio-frequency input arrangements
a) Antenna simulation networks (artificial antennas)
Whereas the rated source impedances of signal sources for measurement purposes (signal
generators, etc.) are usually resistive and well-defined, the source impedances of antennas
have a wide range of values and are neither resistive nor independent of frequency. It is
often necessary, therefore, to insert between the signal source and the receiver input an
antenna simulation network which matches the signal source correctly and presents to the
receiver a source impedance simulating that of the appropriate antenna. Requirements for
antenna simulation networks and examples are detailed in IEC 60315-1.
Measurements on receivers with external antenna terminals should be made using a signal
generator whose rated output impedance is the same as the rated input impedance of the
receiver.
Antenna substitution networks, and combining networks for the injection of more than one
signal, should match the appropriate impedance at both ends, so as to allow insertion
loss to be defined accurately. Networks with minimum insertion loss should be used
while minimizing intermodulation between multiple signal sources. Figure 7 gives simple and
practical examples which are suitable for use with signal generators that have a 50 Ω output
impedance.
b) Balanced inputs
Certain f.m. broadcast receivers are equipped with a balanced antenna input circuit, usually
with a rated characteristic impedance of 240 Ω or 300 Ω. Such receivers shall be measured
with an impedance-matched, balanced signal source. Where a balanced source is not
available, a balun transformer may be used, allowing for its insertion loss. Care shall be
taken that impedance matching is preserved throughout the circuit between the signal
source and the antenna terminals of the receiver.

60315-4 © IEC:1997 – 25 –
1.4.2.8 Standard measuring conditions
A receiver is operating under standard measuring conditions when:
a) the power supply voltage and frequency are equal to, or within the range of, the rated
values;
b) the standard radio-frequency test signal is applied via the appropriate artificial antenna to
the antenna terminals of the receiver;
c) the audio-frequency output terminals for connection to loudspeakers, if any, are connected
to audio-frequency substitute loads;
d) the receiver is tuned to the applied signal according to 1.4.4.2;
e) the volume control, if any, is adjusted so that the output voltage at the main audio-frequency
output terminals is 10 dB below the rated distortion-limited output voltage. Measurements
may also be made at other stated values of output voltage or power;
NOTE – If, during the course of measurement, the a.f. output voltage rises to approach the rated output voltage,
it is essential to adjust the volume control so that the a.f. amplifier is not driven into overload distortion. Such
adjustments should be reported with the results.
f) the environmental conditions are within the rated ranges;
g) for stereo receivers, the balance control or its equivalent, if any, is adjusted so that the
output voltages of the two channels are equal;
h) the tone controls, if any, are adjusted for the flattest possible audio-frequency response
(e.g. for equal response at 100 Hz, 1 kHz and 10 kHz);
i) the automatic frequency control (AFC) is inoperative, if this can be achieved by means of a
user control;
NOTE – Where a user control of automatic frequency control operation is provided, measurements should be
made both with the automatic frequency control off (which will allow easy analysis of the results), and with
automatic frequency control on (which represents the situation when the receiver is in normal use). The two sets
of results should be clearly identified.
If the automatic frequency control cannot be made inoperative by means of a user control, it may nevertheless
be necessary (or desirable) for the automatic frequency control to be disabled for certain measurements. In this
case the automatic frequency control should be disabled by temporarily modifying the receiver, the action taken
being detailed with the results (see 1.4.4.1).
j) the muting control, if any, is in the muting off position.
1.4.3 Power supply and relevant measuring conditions
1.4.3.1 Types of power supply
The receiver under test shall be operated by the type of power supply specified by the
manufacturer. Some receivers are designed to be operable by more than one type of power
supply. Methods of measurement of receiver characteristics relating to the type of power
supply are detailed in IEC 60315-1.
1.4.4 Tuning
1.4.4.1 Effect of automatic frequency control
All tuning operations shall be carried out, having made arrangements to render the automatic
frequency control inoperative, if this is possible, except when the performance of the auto-
matic frequency control is being investigated. When provision is made for the user to render
the automatic frequency control inoperative, measurements may be made both with the
automatic frequency control in operation and disabled. The results shall clearly show whether
the automatic frequency control was in operation or not.

60315-4 © IEC:1997 – 27 –
1.4.4.2 Preferred tuning method
If the receiver has a tuning indicator, the receiver shall be tuned according to the
manufacturer's instructions on the use of the indicator: this corresponds to the way that the
receiver is tuned when in use.
If there is no tuning indicator, or the tuning indicator does not function correctly, the receiver
shall first be tuned approximately to the signal and the audio output signal observed on an
oscilloscope. The deviation shall then be increased until the audio signal becomes distorted,
and the receiver shall be tuned for symmetrical clipping of the audio signal, the volume control,
if any, being adjusted to prevent overload of the audio-frequency part of the receiver from
occurring.
If an alternative method of tuning is used, this shall be stated with the results.
1.5 General notes on measurements
1.5.1 Values for voltage and current
Unless otherwise stated, the terms voltage, current and so on refer to root mean square
(r.m.s.) quantities.
1.5.2 Audio-frequency measurement techniques
The characteristics of devices such as loudspeakers and audio-frequency distribution lines, for
the connection of which output terminals are provided on receivers, are defined (for example,
in IEC 60268-1) in terms of constant input voltage rather than constant input power. This
applies not only to audio-frequency outputs but also to other outputs, for example intermediate-
frequency outputs and multiplex signal outputs. For this reason, it is at present accepted
practice to make most measurements at output terminals in terms of the voltage across a
substitute load. From this voltage, the power in the load may be calculated, if required,
according to the following formula:
U
P =
R
where the suffix 2 refers to output terminals as opposed to input terminals.
Where the output signal is a substantially pure sine wave (with less than 10 % noise and
distortion content), measurements may be made with an average-reading meter scaled in
r.m.s. values for sinusoidal input. Under any other conditions, a true r.m.s. meter shall be used,
unless otherwise stated.
Where several pairs of output terminals are provided, the manufacturer shall state for each
pair:
a) the rated value of the substitute load, (see IEC 60315-1);
b) whether the pair of terminals shall be or shall not be connected to a substitute load when
measurements are made at another pair of terminals.
NOTE – It is usual to connect all terminals intended for loudspeakers to substitute loads for all measurements,
while pairs of terminals for other devices are loaded only when measurements are made at those terminals.

60315-4 © IEC:1997 – 29 –
1.5.3 Presentation of radio-frequency signal level or voltage
Radio-frequency signal levels may be stated as dB(fW), dB(pW), dB(mW) or e.m.f. in
microvolts with stated source or load impedance. The relationship among these values is given
in table 4.
Table 4 – Presentation of radio-frequency signal level or voltage
Available power
EMF (75 Ω) EMF (300 Ω)
W dB(fW) dB(mW)
μVdB(μV) μVdB(μV)
–15
10 0 –120 0,55 –5 1,1 1
–14
10 10 –110 1,75  5 3,5 11
–13
10 20 –100 5,5 15 11 21
–12
10 30 –90 17,5 25 35 31
–11
10 40 –80 55 35 110 41
–10
10 50 –70 175 45 350 51
–9
10 60 –60 550 55 1 100 61
–8
10 70 –50 1 750 65 3 500 71
–7 4
10 80 –40 5 500 75 81
1,1 × 10
–6
4 4
10 90 –30 85 91
1,75 × 10 3,5 × 10
–5
4 5
10 100 –20 95 101
5,5 × 10 1,1 × 10
–4
5 5
10 110 –10 105 111
1,75 × 10 3,5 × 10
–3
5 6
10 120 0 115 121
5,5 × 10 1,1 × 10
–2
6 6
10 130 10 1,75 × 10 125 3,5 × 10 131
1.5.4 Climatic and environmental conditions
For information on environmental conditions, reference shall be made to section one
of IEC 60315-1. Measurements and mechanical checks may be carried out at any combination
of temperature, humidity and air pressure within the limiting values specified in IEC 60315-1.
Furthermore, to prevent unnecessary disturbance from external interfering signals, it is
desirable to carry out the measurement in a screened enclosure or room, (see also IEC 60315-3).
1.5.5 Preconditioning and preliminary measurements
Before recording the results of measurements, the receiver under test should be maintained for
at least 10 min in the state of standard measuring conditions, (see IEC 60315-1).
As the results of the various measurements described in this part may be influenced by other
properties of the receiver, the related measurements given in IEC 60315-1 (if applicable)
should normally be carried out first.
1.5.6 Test equipment and accuracy of measurements
In general, this standard calls for the use of the simplest test equipment that gives acceptably
reliable results. This does not preclude the use of more complex equipment which can be
shown to produce the same, or more reliable, results.

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For information on the accuracy of measuring instruments, the presentation of results and
deviations from the recommended methods, reference shall be made to section one
of IEC 60315-1.
Care should be taken to ensure that any possible shift of the mean carrier frequency due to
modulation is sufficiently small to avoid affecting the measurements.
1.5.7 Rated values
In this part the term rated is used in the special sense of the value specified by the
manufacturer. This term is used when describing rated conditions and rated values of
characteristics.
1.5.7.1 Rated conditions
To define the conditions under which the performance of the receiver is specified and shall be
tested, the manufacturer shall state the following values:
– rated power supply voltage(s) and frequency (or frequency range);
– rated characteristic impedance of the r.f. signal input (where applicable);
– rated value of the substitute load (for each pair of output terminals) (see 1.4.1.2);
– rated total harmonic distortion at which the rated (distortion-limited) output voltage or power
is specified;
– rated environmental conditions (ranges of temperature, pressure and humidity).
These values, by their nature, cannot be determined by measurement.
1.5.7.2 Rated values of characteristics
The climatic and environmental conditions given in 1.5.4 and the electrical conditions given
in 1.5.7.1 enable the manufacturer to specify, and the testing authority to verify, the
performance characteristics of the receiver. The manufacturer shall specify rated values for
important characteristics.
Examples of such characteristics are as follows:
– adjacent and alternate channel selectivity (see 3.2);
– usable sensitivity for a specified signal-to-noise ratio (see 2.5);
– ultimate signal-to-noise ratio (see item c) of 2.7.1 and 1.3.10);
– distortion-limited output voltage or power (see item b) of 5.2.1);
– maximum usable source available power or e.m.f. (see item c) of 5.2.1).
The manufacturer shall clearly define whether these rated values are limit values or median
values. In the latter case a tolerance shall be given (see IEC 60315-1).
1.5.8 Presentation of measuring results
The relation between two or more quantities may often be more clearly presented as a graph
rather than as a table. Values based on theoretical expectation and those based on real
measurement shall be clearly distinguished from each other (see IEC 60315-1).

60315-4 © IEC:1997 – 33 –
2 Sensitivity and internal noise
2.1 Explanation of terms
The sensitivity of a receiver is a measure of its ability to receive weak signals and produce an
audio-frequency output of usable magnitude and acceptable quality. Sensitivities may be
defined with respect to many different characteristics of the output signal, including the
following:
a) signal-to-noise ratio (see 2.2 and 2.3);
b) output voltage or power (with the volume control, if any, at maximum) (see 2.4);
c) limiting level (see item a) of 2.7.1).
For sensitivity measurements a circuit such as that shown in figure 8 is used.
2.2 Signal-to-noise ratio (weighted and unweighted) and SINAD
2.2.1 Introduction
The signal-to-noise ratio of a receiver, under specified conditions, is the ratio of the audio-
frequency output voltage due to the signal to that due to random noise. The noise may be
measured:
a) using the band-pass filter with a 3 dB bandwidth of 22,4 Hz to 15 kHz (see 1.4.1.3 and figure
2), together with a true r.m.s. meter or an average-responding meter calibrated in r.m.s.
values for a sinusoidal signal;
b) using the A-weighting defined in IEC 60651 and a true r.m.s. meter;
c) using the weighting filter and meter defined in annex A of IEC 60315-1;
d) using a band-pass filter w
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