1、= 3LtOY583 0077537 TIT EUROPEAN STANDARD EN 60244-11 NORME EUROPENNE EUROPISCHE NORM April 1993 UDC 621.396.7 : 621.317.3.08 Supersedes HD 236.11 SI : 1990 Descriptors: Radio equipment, sound broadcasting, transmitter, transposer, frequency modulation, measurement, characteristic English version Met
2、hods of measurement for radio transmitters Part 11: Transposers for FM sound broadcasting (IEC 244-11 : 1989) Mthodes de mesure applicables aux metteurs radiolectriques radiodiffusion sonore modulation de frquence MeBverfahren fr Funksender Teil 11: Umsetzer fr FM-ibnrundfunk Onzime partie: Rmetteur
3、s pour la (IEC 244-11 1989) (CE1 244-11 : 1989) 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 of a national standard without any al
4、teration. 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 version in any other language made by
5、 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, France, Germany, Greece, Iceland,
6、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 Normung Central Secretariat: rue de Stass
7、art 35, B-1050 Brussels O 1993 Copyright reserved to CENELEC members Ref. No. EN 60244-11 : 1993 E 3404583 0077538 95b = Page 2 EN 60244-11 : 1993 Foreword At the request of 72nd Technical Board, HD 236.11 S1 : 1990 (IEC 244-11 : 1989) was submitted to the CENELEC voting procedure for conversion int
8、o a European Standard. The text of the International Standard was approved by CENELEC as EN 60244- 11 on 9 March 1993. The following dates were fixed: - latest date of publication of an identical national standard (dop) 1994-06-01 - latest date of withdrawal of conflicting national standards (dow) -
9、 Annexes designated normative are part of the body of the standard. In this standard, annex ZA is normative. INTRODUCTION m 3404583 0077539 892 m page 3 EN 60244-11 : 1993 CONTENTS Page . 4 Clause 1 . Scope 4 2. Object 4 SECTION ONE . GENERAL CONDITIONS OF OPERATION AND MEASUREMENT 3 . Definition 5
10、4 . Input and output signal arrangement 5 5 . General conditions regarding input signal source and test load . 5 6 . Terms and definitions for input and output signals 6 7 . General conditions of operation . 7 SECTION Two . INPUT AND OUTPUT LEVELS AND GENERAL TRANSPOSER CHARACTERISTICS 8 . Input imp
11、edance mismatch 7 9 . Adjustment and measurement of input levels . 7 11 . Adjustment and measurement of output power 8 12 . Frequency . 8 10 . Automatic gain control 7 13 . Internally generated unwanted signals at the transposer input 9 SECTION THREE . TRANSMISSION PERFORMANCE CHARACTERISTICS 14 . A
12、mplitude/ baseband-frequency characteristic . 9 16 . Harmonic distortion in the coded channels of a stereophonic service . 10 17 . Crosstalk attenuation (stereophonic separation) 11 19 Baseband-frequency intermodulation 12 15 . Audio-frequency harmonic distortion 10 18 . Linear and non-linear crosst
13、alk between A and B channels 11 20 . Transmission performance for supplementary services (under consideration) . 13 . . 21 . 22 . 23 . 24 . 25 . 26 . 27 . 28 . SECTION FOUR . UNWANTED MODULATION AND SPURIOUS EMISSIONS Introduction 13 Unwanted frequency modulation 13 Unwanted amplitude modulation 15
14、Spurious emissions in the absence of interfering input signals Spurious emissions in the presence of interfering input signals Changes in performance caused by feedback from output to input . Unwanted modulation in the presence of an interfering input signal Unwanted modulation signals in the presen
15、ce of two interfering input signals 16 17 17 17 18 . APPENDIX A . Input impedance 21 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications 22 m 3404583 0077540 504 m Page 4 EN 60244-11 : 1993 METHODS OF MEASUREMENT FOR
16、 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 IEC Publication 244 a
17、re 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 sp
18、ecialist 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: Pub
19、lication 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 app
20、lies 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
21、, 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
22、be in accordance with relevant standards published by the I E C 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
23、 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. m 3404583 0077543 440 m Page 5 EN 60244-11 : 1993 For guidance on the information to be given in descriptive leaflets particular to the ty
24、pe of equip- ment considered in this standard, refer to the relevant sections of I E C 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
25、 these terms.) SECTION ONE - GENERAL CONDITIONS OF OPERATION AND MEASUREMENT 3. Definition 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 ant
26、enna 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
27、 the transposer, shall be considered to be part of the transposer for the purpose of this standard. 4. Input and output signai 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
28、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, -
29、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
30、, 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 regardin
31、g 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. W 3404583 O077542 387 W Page 6 EN 60244-11 : 1993 5.2 Test load The transposer shall be te
32、rminated 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 unwant
33、ed frequency outside this band. Connection of measuring equipmeni to the transposer of which is used to feed the radio-frequency test equipment. 5.3 The preferred arrangement for the test load for low power transposers is an attenuator, the output Alternatively, especially for high power transposers
34、, 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 calib
35、rated 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
36、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 (I 1 000 Hz), with a specified frequency deviation. If required, other audio modulation frequencies may be c
37、hosen. 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, I 1 O00 Hz, shall be applied to both left-hand channel A
38、 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. e) Addi
39、tional 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 fre
40、quency modulated r.f. carrier at the input of the transposer expressed in pV or dB(pV). b) Reference input level The reference input level for a monophonic or stereophonic input signal is 60 dB(pV), i.e. 1 mV. c) Input voltage range The input voltage range of a transposer is the range of input volta
41、ge within which the transposer performance specifications apply. M 3404583 00775Y3 213 = Page 7 EN 60244-11: 1993 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 ca
42、rrier. b) Reference output level The reference output level (O 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 (se
43、e I E C 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
44、 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). in Clause 28
45、. Note. - Special measurements concerning transposer instability due to coupling between the input and output are described 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
46、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. Note. - When an input filter is used, the measurement should be restricted to the pass-band of the transposer. 9. Adj
47、ustment 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 throug
48、h 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 manufac
49、turers instructions. Note. - Normally limiters in the FM transposers will ensure constant output power. m 3YOY583 0077544 L5T m Page 8 EN 6024411 : 1993 11. Adjustment and measurement of output power 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,
