1、CCIR VOLUME*X-3 90 4855232 0503989 T 112 Rec. 415-2 RECOMMENDATION 415-2 * MINIMUM PERFORMANCE SPECIFICATIONS FOR LOW-COST SOUND-BROADCASTING RECEIVERS The CCIR, (1963-1982-1986) CONSIDERING (a) that the advantages of broadcasting should be made more.easily available to the populations of the countr
2、ies where, at present, the density of receivers is particularly low due to economic, geographical or technical reasons; (b) that to this end, it is desirable that efficient broadcasting receivers should be available at prices low enough to secure their wide distribution in those countries; (c) that
3、general agreement on the performance of suitable broadcasting receivers would prove most useful to radio receiver manufacturers by assisting them to produce suitable receivers, having an agreed adequate standard of performance, at the lowest possible cost, UNANIMOUSLY RECOMMENDS that the minimum per
4、formance specifications, contained in Annex I, be used to assist in the design and development of low-cost sound broadcasting receivers suitable for production in large quantities. ANNEX I These specifications apply to the following types of receivers: Type A : a low sensitivity receiver for operati
5、on in band 6 (MF), Type B : a combined receiver for operation in bands 6 (MF) and 7 (HF), Type C : a medium sensitivity frequency-modulation receiver for operation in band 8 (VHF). , 1. General 1.1 Each of the three types of receiver should be available for either mains or battery operation. For bat
6、tery operation, all three types of receiver should be fully solid state to ensure economy of power consumption. For mains operation, either valves or transistors may be used, consideration of cost being the guiding factor. 1.2 For battery-operated receivers, the minimum performance spec-ifications l
7、isted in this Recommendation should be achieved for the nominal battery voltage less 30% as specified in the relevant IEC publication. 1.3 The methods of measurement employed should be those recommended in the relevant IEC publications for amplitude-modulation receivers and frequency-modulation rece
8、ivers. 1.4 The receivers should be simple, robust and well protected against dust. Those intended for use in regions of high temperature and humidity should be treated so that they can be used under the climatic conditions laid down by the Administration concerned. The appropriate tests required by
9、the Administration procuring such receivers should comply with the relevant IEC publications. 1.5 If national regulations prescribe methods of measurement or tests differing from the standard IEC methods, Administrations will, where necessary, draw attention to this difference. 1.6 In the case of co
10、mmunity listening, higher output powers are necessary, whereas the other requirements remain unchanged. * This Recommendation contains text from the former Recommendation 416 which is hereby cancelled. CCIR VOLUME*X-1 90 4855212 0503990 b I Rec. 415-2 113 I 2. Specification for Type A receivers 2.1
11、Frequency coverage (kHz) 2.2 at 400 Hz Sensitivity for 50 mW output 30% modulation 2.3 SignaVnoise ratio for input as under 0 2.2 2.4 Power output, for less than 10% distortion 2.5 Overall selectivity at - 6 dB points at -20 dB points Image, intermediate frequency and spurious 2.6 response ratio 2.7
12、 loudspeaker, or, Alternatively, it may be more convenient for some manufacturers to consider only the electrical charac- teristics which should be Overall fidelity including acoustic response of 526.5-1606.5 (Regions 1 and 3) 525-1705 (Region 2) 5 mV/m (with a built-in antenna with facilities for u
13、sing an external antenna) 20 dB (mains-operated tube receivers) 26 dB (transistor receivers) not less than 0.1 W passband not less than f 3 kHz passband not greater than f 10 kHz not less than 30 dB 250-3150 Hz, within 18 dB limits 10.0-4000 Hz within 12 dB limits (in a graphical pres- entation 400
14、Hz should be taken as the reference O dB level) 3. Specification for Type B receiver (the two types differing only in frequency range) 3.1 Frequency coverage (MHz) B1 : 0.5265-1.6065; 2.3-15.6 (Regions 1 and 3) 0.5250-1.7050; 2.3-15.6 (Region 2) B2 : 0.5265-1.6065; 2.3-21.85 (Regions 1 and 3) 0.5250
15、-1.7050; 2.3-21.85 (Region 2) The receiver shall be provided with adequate mechan- ical and/or electrical means for easy tuning. 3.2 at 400 Hz 3.3 Sensitivity for 50 mW output 30% modulation Signal-to-noise ratio, for input as under 0 3.2 Power output, for less than 10% distortion not worse than 150
16、 pV 20 dB (mains-operated tube receivers) 26 dB (transistor receivers) not less than than 0.1 W 3.4 3.5 Overall selectivity at - 6 dB points at -20 dB points at -40 dB points passband not less than & 3 kHz passband not greater than f 10 kHz passband not greater than f 20 kHz 3.6 Image, intermediate
17、frequency and spurious response ratio MF - not less than 30 dB Intermediate frequency and spurious response ratio HF - not less than 12 dB Image response ratio HF - not less than 5 dB 3.7 Overall fidelity including acoustic response of loudspeaker, or, Alternatively, it may be more convenient for so
18、me manufacturers to consider only the electrical charac- teristics which should be 250-3150 Hz within 18 dB limits 100-4000 Hz within 12 dB limits (in a graphical pres- entation 400 Hz should be taken as the reference O dB level) 114 CCIR VOLUME*X-L 90 4855232 0503993 8 Rec. 415-2 3.8 input is reduc
19、ed by 30 dB from Oil V i A.g.c. performance: change in output when the 3.9 4. 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Frequency stability Specification for Type C receivers Frequency coverage (MHz) Signal-to-noise ratio Sensitivity (noise limited) Intermediate frequency Amplitude-modulation suppression rati
20、o Power output Overall selectivity Overall fidelity including acoustic response of loudspeaker, or, Alternatively, it may be more convenient for some manufacturers to consider only the electrical charac- teristics which should be 4.9 Radiation 4.10 Distortion 4.1 1 Frequency stability not greater th
21、an 10 dB must be such that the receiver does not require frequent retuning 87.5-108 (Region i) 88 -108 (Region 2) 87 -108 (Region 3) 30 dB -75 dB rel. 1 mW (at a signal-to-noise ratio of 30 dB and 50 mW output power) 10.7 MHz 20 dB not less than 0.1 W -30 dB at f 300 kHz 200-5000 Hz within 18 dB lim
22、its 100-5000 Hz within 6 dB limits (in a graphical presen- tation 400 Hz should be taken as the reference O dB level) the local oscillator radiation should be less than the limits specified by CISPR. However, where national regulations exist, the radiation should be less than the limits specified therein the distortion should be less than 5% for a frequency deviation varying between 3. 15 kHz and f 75 kHz with a modulation frequency of 400 Hz and an output power of 50 mW must be such that the receiver does not require frequent retuning.
