1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-20792-2 SANS 996:2008Edition 3.1Any reference to SABS 996 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 Nove
4、mber 2002)SOUTH AFRICAN NATIONAL STANDARD Car radio receivers Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 996:2008 Edition 3.1 Table of chan
5、ges Change No. Date Scope Amdt 1 2008 Amended to change the designation from SABS to SANS, to update the definition of “acceptable“, to change the language requirements with regard to the manual and identification marking, to move references to legislation to the foreword, to update the Regulator, a
6、nd to update referenced standards. Acknowledgement The South African Bureau of Standards wishes to acknowledge the valuable assistance rendered by Mr TB Willis, who was closely involved in the drafting of this standard. Foreword This South African standard was approved by National Committee StanSA T
7、C 74, Communication technology, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This document was published in April 2008. This document supersedes SABS 996:1994 (edition 3). A reference is made in 5.2 to “Radio Regulations“ and in NOTE 1
8、 to 5.2 to “legislation“. In South Africa this means the Electronic Communications Act, 2005 (Act No. 36 of 2005) (as amended from time to time) and the Radio Regulations promulgated in terms of the Act. Amdt 1 A reference is made in NOTE 2 to 5.2 to the “relevant Regulator“. In South Africa this me
9、ans the Independent Communications Authority of South Africa. Amdt 1 A vertical line in the margin shows where the text has been technically modified by amendment No. 1. Annex A is for information only. SANS 996:2008 Edition 3.1 1 Contents Page Acknowledgement Foreword 1 Scope 3 2 Normative referenc
10、es 3 3 Definitions . 3 4 General and constructional requirements . 8 5 Electrical requirements 10 6 Inspection and methods of test . 13 6.1 Standard test conditions 13 6.2 Setting of tone control(s) 15 6.3 Tuning 15 6.4 Bump resistance test . 16 6.5 Vibration, tuning stability and battery voltage va
11、riation tests 16 6.6 Resistance to impact . 17 6.7 Resistance to environmental conditions, and memory stability . 18 6.8 Resistance to surge discharge 19 6.9 Maximum useful electrical output power (MUOP) . 19 6.10 Noise-limited sensitivity . 20 6.11 Image frequency suppression ratio . 21 6.12 Select
12、ivity for AM . 21 6.13 Spurious responses (FM only) . 22 6.14 Automatic gain control (AM only) . 22 6.15 Input signal level/output power characteristic (FM only) . 23 6.16 Amplitude-modulation suppression ratio (FM only) . 23 6.17 Tuning ranges 24 6.18 Overall electrical frequency response . 24 6.19
13、 Crosstalk (stereo only) . 25 6.20 Mono/stereo switch-over 25 6.21 Stereo noise-limited sensitivity 26 6.22 Stereo indicator Time delay (where fitted) 26 7 Standard test conditions and methods of test for RDS (where applicable) . 26 7.1 Test conditions . 27 7.1.1 Standard RDS measuring signal . 27 7
14、.1.2 RDS data conditions . 27 7.1.3 Conditions for measurement . 27 7.2 Methods of test 27 7.2.1 RDS sensitivity 27 7.2.2 RDS switching criteria . 28 8 Marking . 29 Figures 1 to 6 . 30-34 Annex A (informative) Bibliography 35 SANS 996:2008 Edition 3.1 This page is intentionally left blank SANS 996:2
15、008 Edition 3.1 3 Car radio receivers 1 Scope This standard specifies the minimum electrical and related requirements that are essential for the successful reception (under normal conditions) of sound broadcast transmissions, including stereophonic transmissions and radio data services where applica
16、ble, in the recognized medium frequency, high frequency and very high frequency bands, by radio receivers designed for use in motor vehicles. It also specifies certain mechanical requirements and the minimum information to be supplied with each receiver. NOTE The life and design of receivers and the
17、 quality and performance of additional facilities such as tape playback units are not covered, but see 4.1.2. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this standard. All standards are subject to revision and, si
18、nce any reference to a standard is deemed to be a reference to the latest edition of that standard, parties to agreements based on this standard are encouraged to take steps to ensure the use of the most recent editions of the standards indicated below. Information on currently valid national and in
19、ternational standards can be obtained from Standards South Africa. IEC 60068-1, Environmental testing Part 1: General and guidance. IEC 60068-2-6, Environmental testing Part 2-6: Tests Test Fc: Vibration (sinusoidal). IEC 60068-2-29, Basic environmental testing procedures Part 2-29: Tests Test Eb an
20、d guidance: Bump. IEC 60068-2-75, Environmental testing Part 2-75: Tests Test Eh: Hammer tests. Amdt 1 3 Definitions For the purposes of this standard, the following definitions apply: 3.1 acceptable acceptable to the local authority in whose area of jurisdiction the system is installed, or to the b
21、ody administering this standard, as relevant Amdt 1 SANS 996:2008 Edition 3.1 4 3.2 amplitude-modulation (AM) suppression ratio of a frequency modulation (FM) receiver a figure that represents the ability of an FM receiver to reject amplitude modulation of the input signal 3.3 artificial aerial a ne
22、twork by which the electrical properties of a receiving aerial are simulated during tests 3.4 automatic frequency control a circuit arrangement that automatically keeps a receiver closely tuned to the frequency of a sufficiently strong signal 3.5 automatic gain control a circuit arrangement that aut
23、omatically adjusts the overall gain of the high frequency or intermediate frequency stages, or both, of a receiver in order to reduce the variation of output power for a change (within certain limits) of input signal level 3.6 broadcast frequency bands a) medium frequency (MF) band : A band of frequ
24、encies that lie in the range 520 kHz to 1 610 kHz b) high frequency (HF) bands : Bands of frequencies that lie in the range 2,3 MHz to 26,1 MHz c) very high frequency (VHF) band : A band of frequencies that lie in the range 87,5 MHz to 108 MHz 3.7 car bracket a mounting bracket that is designed for
25、installation in a motor vehicle and in which a specific portable radio receiver will fit (the bracket may or need not contain additional electronic equipment) 3.8 car radio receiver receiver a radio receiver that is specifically designed for use in a motor vehicle 3.9 carrier frequency the frequency
26、 of the transmitted carrier wave, in the absence of modulation 3.10 decibel dB a unit that is used to express the ratio of two powers, by ten times the decimal logarithm of this ratio, i.e. N = 10 log10(P1/P2) SANS 996:2008 Edition 3.1 5 where N is the number of decibels; and P1 and P2are the powers
27、 to be compared. NOTE The decibel can also be used to express the ratio of the field quantities (such as voltage or current) involved in the power dissipation. If P1and P2represent the powers dissipated by the currents I1and I2in resistances R1and R2respectively, then the decibel difference N betwee
28、n P1and P2is N = 10 log10(P1/P2) = 10 log10(I12R1)/(I22R2) = 20 log10(I1/I2) + 10 log10(R1/R2) Thus if the two resistances (more generally impedances) are equal, N = 20 log10(I1/I2) and similarly, if V1and V2are voltages across resistances R1and R2respectively, N = 20 log10(V1/V2). 3.11 decibel suff
29、ix a decibel value that is related to a specific reference quantity (this decibel value will define the new quantity absolutely) NOTE The reference quantities used in expressing the levels of power, voltage, current or field strength can be indicated by means of a suffix associated with dB. The foll
30、owing are commonly used references and their suffixes: Reference Abbreviation Quantity Power Voltage Current Field strength 1 picowatt 1 microvolt 1 ampere 1 microvolt per metre dB(pW) dB(V) dB(A) dB(V/m) 3.12 de-emphasis a post-detection process in a receiver, complementary to that used for pre-emp
31、hasis (see “pre-emphasis“) 3.13 defective a receiver that fails in one or more respects to comply with the standard 3.14 image frequency suppression ratio the ratio, expressed in decibels, of the input signal level at the image frequency, to the input signal level at the frequency to which the recei
32、ver is tuned, both giving standard output power when modulated to the same depth NOTE The image frequency is equal to the frequency to which the receiver is tuned, plus or minus twice the intermediate frequency, according to whether the local oscillator frequency is above or below the signal frequen
33、cy. SANS 996:2008 Edition 3.1 6 3.15 input signal level/output power characteristic the curve that indicates the relation between the input signal level and the output power (this curve indicates the performance of the automatic gain control or the limiter, or both) 3.16 level the magnitude, in a ge
34、neral form, of an electrical quantity 3.17 maximum audio range the most uniform audio output power over the greatest part of the audio frequency range that can be obtained by adjustment of the tone control(s) 3.18 maximum rated system deviation the greatest peak frequency deviation of the system und
35、er consideration (in the case of frequency modulation systems in the range 88,7 MHz to 108 MHz, the maximum rated system deviation is 75 kHz) 3.19 maximum useful electrical output power MUOP the highest output power, per channel in the case of stereo receivers, that is obtainable with standard test
36、input signals for which the total distortion does not exceed 10 % 3.20 modulation depth a) of an amplitude-modulated radio-frequency signal: The ratio, expressed as a percentage, of the difference between the maximum instantaneous peak amplitude value of the modulated radio-frequency signal, and the
37、 average peak amplitude value of the unmodulated radio-frequency signal, to the average peak amplitude value of the unmodulated radio-frequency signal b) of a sinusoidal frequency-modulated radio-frequency signal: The ratio, expressed as a percentage, of the peak frequency deviation to the maximum r
38、ated system deviation 3.21 noise-limited sensitivity the minimum input signal level, giving at least standard output power (SOP), at which the specified value of SINAD (see 3.29) is achieved 3.22 overall electrical frequency response characteristic of a receiver the relation, with 50 s pre-emphasis
39、applied, between the electrical output power delivered to the loudspeaker and the modulation frequency, when the modulating signal is of constant voltage 3.23 peak frequency deviation the peak value of the instantaneous frequency deviation 3.24 pre-emphasis a pre-transmission process that is designe
40、d to emphasize the magnitude of certain frequency components with respect to the magnitude of others SANS 996:2008 Edition 3.1 7 NOTE A 50 s pre-emphasis curve is used for VHF broadcasts in South Africa. 3.25 PS the displayed programme service name in RDS mode 3.26 RDS Radio Data System 3.27 satisfa
41、ctory performance the correct display of the programme service name (PS) within 10 s after the beginning of the relevant step of a test NOTES 1 Any eight characters from the available character set may be chosen as the programme service name. The chosen name(s) should be stated with the results. 2 T
42、he correct display of the programme service name is used as the criterion for satisfactory performance because this facility is generally available on RDS receivers and can be used without making internal connections to the receiver circuits. If the PS is not available, another stated criterion may
43、be used, which necessitates internal connections to the receiver. In this case, correlation between this criterion and the PS should be established (if possible) and stated with the results. 3.28 selectivity of a receiver the ability of a receiver to separate a desired signal from an undesired one o
44、n a nearby frequency 3.29 Signal Input Noise And Distortion ratio SINAD ratio the ratio, expressed in decibels, of the r.m.s. value of the receiver output when the input voltage is a radio-frequency signal modulated by a pure sinusoidal voltage at standard modulation depth, to the r.m.s. value of th
45、e receiver output excluding output at the modulating frequency NOTE The SINAD ratio is given by the formula SINAD = 20 log10(S + N + D)/(N + D) dB where S, N and D represent signal, noise and distortion respectively. 3.30 standard output power SOP an output power of 500 mW 3.31 total harmonic distor
46、tion of a receiver THD the ratio, expressed as a percentage, of the r.m.s. value of the receiver output when a pure sinusoidal input voltage is applied, to the r.m.s. value of the receiver output excluding output at the input signal frequency SANS 996:2008 Edition 3.1 8 NOTE The THD of a receiver is
47、 given by the formula THD = (N + D)/(S + N + D) x 100 % where S, N and D represent signal, noise and distortion respectively. 3.32 tuning ranges of a receiver the frequency ranges that are covered by all the frequency bands available on the receiver 3.33 voltage and current values the root mean squa
48、re values of the voltages or currents NOTE An exception is made where modulation is present on a signal; then the r.m.s. value of the pure sinusoidal carrier component is meant. The true r.m.s. value of an amplitude-modulated signal will differ from this value, the magnitude of the difference depend
49、ing on the depth of modulation. 4 General and constructional requirements 4.1 General 4.1.1 Construction The construction and workmanship of a receiver shall be such as to be acceptable. 4.1.2 Additional facilities Additional facilities that are not covered by this standard, but are provided either as integral parts of, or additions to, a receiver that complies with this standard, shall function in every respect in accordance with the claims of the manufacturer and shall, when applicable, comply with the relevant standards. 4.1.3 Dissimilar metals
