1、EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM 3404583 0084555 LbL EN 60244-13 April 1993 UDC 621.396.61 : 621.396.93 : 620.1.083 : 621.317.083 Descriptors: Radio equipment, transmitter, sound broadcasting, frequency modulation, operating characteristics, quality English version Methods of measur
2、ement for radio transmitters Part 13: Performance characteristics for FM sound broadcasting (IEC 244-13 1991) Mthodes de mesure applicables aux metteurs radiolectriques Partie 13: Qualits de fonctionnement des metteurs de radiodiffusion sonore modulation de frquence (CE1 244-13 1991) MeGverfahren fr
3、 Funksender Teil 13: bertragungseigenschaften fr FM-Tonrundfunk (IEC 244-13 : 1991) This European Standard was approved by CENELEC on 1993-03-09. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status o
4、f a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A v
5、ersion in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland
6、, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normu
7、ng Central Secretariat: rue de Stassart 35, B-1050 Brussels O 1993 Copyright reserved to CENELEC members Ref. No. EN 60244-13 : 1993 E D 3404583 0084556 OT8 Page 2 EN 60244-13 : 1993 Foreword The CENELEC questionnaire procedure, performed for finding out whether or not the International Standard IEC
8、 244-13 : 1991 could be accepted without textual changes, has shown that no common modifications were necessary for the acceptance as European Standard. The reference document was submitted to the CENELEC members for formal vote and was approved by CENELEC as EN 60244-13 on 9 March 1993. The followi
9、ng dates were fixed: - latest date of publication of an identical national standard (dop) 1994-03-01 - latest date of withdrawal of conflicting national standards (dow) 1994-03-01 Annexes designated normative are part of the body of the standard. In this standard, annexes A, B and ZA are normative.
10、3404583 0084557 T34 Page 3 EN 60244-13 : 1993 CONTENTS INTRODUCTION . . 4 Clause 1 2 3 4 5 6 7 8 9 10 11 scope . Nonnative references . . General terms and definrtions General conditions of operation . General conditions of measurement General characteristics Transmission performance characteristics
11、 Unwanted modulation Out-of-band emission (Occasional measurement) . Assessment for transmitter equipped with limiters (Under consideration) Special measurement for supplementary signals (Under consideration) Measuring arrangement I Measuring arrangement II 5 5 6 7 7 8 8 15 19 21 21 22 23 Annexes (n
12、ormative) A CCIR Recommendation 468-4 . 24 B Extract from CCIR Recommendation 559 31 ZA Other international publications quoted in this standard with the references of the relevant European publications . . . . . . , . . , . . , , . . , . . , . . , 32 Page 4 EN 60244-13 : 1993 INTROOUCTION This Inte
13、rnational Standard is one of a series of parts of IEC 244. A number of existing parts of IEC 244 are currently under review and several of these will be revised or withdrawn. When this process is complete, this series of publications will comprise one part dealing with general characteristics, with
14、cross-references to relevant CCIR publications and the Radio Regulations, and a number of specialized parts, each dealing with particular types of transmitter. In most cases references to CCIR publications deliberately omit the revision number: il is assumed that reference will always be made to the
15、 later revision of CCIR publications. An exception is made here for Recommendation 460-4, whose text is reproduced in full in this publication. 3404583 0084559 807 Page 5 EN 60244-13 : 1993 METHODS OF MEASUREMENT FOR RADIO TRANSMITTERS Part 13: Performance characteristics for FM sound broadcasting 1
16、 Scope This International Standard contains the method of measurement to assess the performance characteristics of frequency modulated transmitters for sound broadcasting. To assess all other characteristics, this standard needs to be used in conjunction with the publications quoted in clause 2. Thi
17、s standard is intended to be used for type tests and acceptance or factory tests. It is not mandatory to measure all the described characteristics. Additional measurements may be carried out as an agreement between customer and manufacturer. The performance characteristics measured in accordance wit
18、h this standard makes possible the comparison of the results of measurements made by different observers. Limiting values for acceptable performance are not covered by this standard but, in connection with the presentation of measured characteristics, some data are given for clarity. 2 Normative ref
19、erences The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International
20、Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain regis- ters of currently valid International Standards. 2.1 IEC publications 215: 1987, Safety requirements for radio transmitting equipment.
21、Amendment No. 1 (1990). 244-1 : 1968, htethods of measurement for radio transmitters - Part I: General conditions of measurement, frequency, output power and power consumption (under revision). Amendment No. 2 (1989) to IEC 244-1A (1968), Methods of measurement for radio transmitters - Part 1: Gener
22、al conditions of measurement, frequency, output power and power consumption - First supplement: Appendices. 3404583 0084560 529 Page 6 EN 60244-13 : 1993 244-1 2-1 : 1989, Methods of measurement for radio transmitters - Part 12: Guideline for drawing up descriptive leaflets for transmitters and tran
23、sposers for sound and television broadcasting - Characteristics to be specified. 244-1 2-2: 1989, Methods of measurement for radio transmitters - Part 72: Guideline for drawing up descriptive ieaflets for transmitters and transposers for sound and television broadcasting - Specification sheets. 864-
24、 1 : 1 986, Standardization of interconnections between broadcasting transmitters or transmitter systems and supervisory equipment - Part 7: Interface standards for systems using dedicated interconnections. 2.2 CCIR publications Recommendation 450, Transmission standards for FM sound broadcasting at
25、 VHF. Recommendation 468-4: 1 990, Measurement of audio-frequency noise voltage level in sound broadcasting. Recommendation 559, Objective measurement of radio-frequency protection ratios in LF, MF and HF broadcasting. Recommendation 643, System for automatic tuning and other applications in FM radi
26、o receivers for use with the pilot-tone system. Report 463, Transmission of several sound programmes or other signals with a single transmitter in frequency-modulation sound broadcasting. 3 General terms and definitions 3.1 Frequency modulated sound transmitter The term “frequency modulated sound tr
27、ansmitter” is used in this standard to denote equipment with a FM radio-frequency output and a baseband frequency input which can accept monophonic, stereophonic and supplementary service multiplexed signals. 3.2 Description of the transmission systems for FM sound broadcasting The transmission syst
28、ems for FM sound broadcasting are laid down in CCIR Recom- mendation 450. Supplementary services are described in CCIR Report 463 and CCIR Recom- mendation 643. 3404583 0084563 465 Page 7 EN 60244-13 : 1993 3.3 Definitions of performance characteristics These definitions are given in the clauses des
29、cribing the method of measurement and are in line with those given in IEC 244-12-1 and IEC 244-12-2. 4 General condltions of operation - The FM sound transmitter shall be tested under normal operating conditions at its rated output: power. - The mains supply and the environmental conditions shall be
30、 stated with the mea- surement results. - The FM sound transmitter shall be connected to a test load which has an impedance expressed in terms of return-loss relative to the nominal load impedance of the transmitter of not less than 26 dB at frequencies within the FM broadcasting band and 16 dB at f
31、requencies of any measured unwanted frequency outside this band. 5 General conditions of measurement 5.1 - shown in the form of diagrams given on pages 42 and 43. - them shall be accurately matched. - Input anti output signal arrangements For the purposes of measurement, the input and output signal
32、arrangements are The impedance of the test equipment, the test object and all connections between The performance characteristics shall be measured via a directional coupler. 5.2 Measuring equipment At the input: - two baseband low distortion generators covering the frequencies up to 100 kHz. The mo
33、dulating signals for the transmitter under test shall be provided by one or - For stereophony, a stereo coder shall be used. If the transmitter does not incorporate a stereo coder, an external test stereo coder shall be used. - If required auxiliary equipment for generating, supplementary signals wi
34、ll be used (e.g. RDS ooder). At the output: - baseband signals, at the output of a test demodulator. - measured. - All measurements concerning the transmission performances shall be carried out at For stereophony, the signais at the output of a test stereo decoder shall be For supplementary signals,
35、 a test decoder shall be used (e.g. RDS decoder). NOTE - Bexiuse the results of these measurements are critically dependent on the performance of the test equipmerit, it is necessary to check first the overall performance of the test equipment in the absence of the transmitter under test. 3404583 00
36、845b2 3TL = Page 8 EN 60244-13 : 1993 5.3 Modulation and output power conditions - The modulation conditions for each measurement are given in the clauses describing the method of measurement. - - The output power is the power of the unmodulated carrier. All measurements shall be carried out at rate
37、d output power. 5.4 Units used As needed, results may either be given in decibels or as percentages. 6 General characteristics The method of measurement of the general characteristics of the transmitter such as input impedance, output power and frequency stability will be described in IEC 244-1 (und
38、er revision). 7 Transmission performance characteristics Measurement can be performed on baseband signals (at frequencies up to a maximum of 1 O0 kHz) and/or audio-frequency signals (at frequencies up to 15 kHz). The baseband measurements are made at the multiplex input of the transmitter. The audio
39、 band limiting and pre-emphasis in the transmitter and the de-emphasis in the demodulator are not in circuit, unless otherwise stated. The audio-frequency measurements are made at the audio input of the transmitter. The audio band limiting and pre-emphasis in the transmitter or stereo coder and the
40、de-emphasis in the demodulator or in the stereo decoder are in circuit, unless otherwise stated. 7.1 Amplitude/baseband-frequency characteristic 7.1 . 1 Definition The amplitude/baseband-frequency characteristic is the variation of the amplitude of the demodulated signal with frequency for a constan
41、t value of the demodulating input signal voltage, relative to the amplitude at a certain reference frequency. 7.1.2 Measuring arrangement Measuring arrangement I, page 42, with one signal generator at the input shall be used. The test demodulator output shall be connected to a spectrum analyser or v
42、oltage measu- ring equipment. 7.1.3 Measurement procedure - circuit. - Check that the pre- and de-emphasis filters and band-limiting filters are out of Adjust the input signal to a specified reference frequency. 3404583 0084563 238 m Page 9 EN 60244-13 : 1993 - specified value. - sweeping up to 76 k
43、Hz (some specifications ask for up to 100 kHz). Adjust the input level so that the frequency deviation of the transmitter has a Vary the frequency of the modulating signal either manually or continuously by - - frequency . - Keep the input level constant. Measure the level of the demodulator output
44、signal as a function of the modulation If required, repeat the procedure for other values of frequency deviation. 7.1.4 Presentation of the results - The results may be presented as a table or a graph relative to the amplitude of the output at reference frequency. The frequency deviation at referenc
45、e frequency shall be stated. 7.2 Baseband-frequency demodulation 7.2.1 Introduction The method of intermodulation measuring is based on the method using two signals with frequencies f, and f2 and equal amplitudes with a frequency difference f2 - fl = 1 kHz. The products of interest are the differenc
46、e tone of 1 kHz and (fi + f2) as the second order pro- ducts and the tones l kHz below fi, (f, - l kHz), and l kHz above f2 (f2 + l kHz), as the third order products. The lowest frequency for fl shall be 3 kHz. 7.2.2 Definition The second order (third order) intermodulation level is the ratio, expre
47、ssed as a per- centage or in decibels, between (1) the arithmetic sum of the r.m.s. values of the second order (third order) intermodulation component and (2) the arithmetic sum of the r.m.s. values of the wanted components at the demodulator output, for a modulation signal consisting of two tones o
48、f equal amplitude, generated within the baseband and spaced 1 kHz apart. 7.2.3 Measuring arrangement Measuring arrangement I, page 42, shall be used. Two baseband generators are connected to the input of the transmitter. The isolation between the output of the gene- rators shall be at least 40 dB. T
49、he spectrum analyser is connected to the output of the demodulator. 7.2.4 Measuring procedure - Check that the pre- and de-emphasis filters and band-limiting filters are out of circuit. - Adjust one input signal to frequency fi. - Adjust the other input signal f2 to a frequency 1 kHz higher. - Adjust both input signals to the same level, so that one modulating signal gives 50 Oh of the specified deviation value of the transmitter under test. 3404583 0084564 174 Page 10 EN 60244-13 : 1993 - Vary the input frequencies up to 76 kHz keeping the input frequency spacing at
