IEC 60107-5:1999 pdf download – Recommended methods of measurementson receivers for television broadcast transmissions – Part 5: Electrical measurements on multichannelsound television receivers using the NICAMtwo-channel digital sound-system

IEC 60107-5:1999 pdf download – Recommended methods of measurementson receivers for television broadcast transmissions – Part 5: Electrical measurements on multichannelsound television receivers using the NICAMtwo-channel digital sound-system.
The methods of measurement described in this part of IEC 60107 apply to television receivers designed for the reception of television broadcasts sing the Iwo-channel digital sound system. The sound coding-system is based in NICAM 728 and is transmitled by a quadrature phase-shift keying (OPSK) modulated digital subcarrier.
NOTE — NICAN 725 is the abbreviated I omi of Near InslanLaneous Conipanded Audio Muiliplev at 728 kLs.
1.2 Normative references
The following normative documents contain provisions which, through reference In this text. constitute provisions of this part of IEC 60107. For dated references, subsequent amendments to. or revisions of. any of these publications do not apply. However, parties to agreements based on this part of lEG 60107 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standard5
lEG 60107-1:1997, Methods of measurement on receivers for television broadcast transmissions — Part 1: General considerations – Measurements at radio and video frequencies
lEG 60107•2:1997, Methods of measurement on receivers for television broadcast transmissions — Part 2: Audio channels — General methods and methods for monophonic channels
IEC 60268-1:1985. Sound system equipment — Part 1: General
ITU -R Recommendation BT .470-5:1998, Conventional television systems
ITU-R Recommendation BS 707-3:1998, TransmIssion of multi.sound In terrestrial television systems PAL B, G. H and I, and SECAM 0. K, KI and L
ITU-T Recommendation J. 17:1972, Pre-emphasis used on sound-programme circuits
2 General explanation of terms
The digital sound system offers the possibility of audio transmission using several different modes of operation:
3 General notes on measurements
The decoder br this sound system Is generally integrated into a television receiver and it is not always possible to measure the data before the DA converter.
3.1 General conditions
Unless otherwise stated, measurements shall be carried out under the conditions described in IEC 60107-1 and IEC 60107-2.
3.2 SettIng of the receiver
3.2.1 IntroductIon
Measurements should be carried out in accordance with the following conditions to ensure measurement reIlablity,
3.2.2 Standard output power and voltage
3.2.2.1 Standard output power for loudspeaker
The standard output power shall be a power 10 dB below the rated output power isee 3.1 of IEC 60107-2). Alternatively, a stated, preferred value of output power, not directly related to the rated value, may be used the preferred values are 500 mW, 50 mW and 5 mW. The corresponding levels are 27 dB(mW), 17 dB(mW) and 7 dB(mW), respectively. In all cases, the value chosen shall be stated with the results.
3.2.2.2 Standard line output voltage
The standard output voltage at a line output terminal shall be 500 mV r.m.s. at I kHz when terminated with a resistor equal to the rated load impedance,
NOTE — It the output is not adjustable. the output vollaQe sst,en the standard r.f. television sinai Is applied to the receiver at the it. input e4naI leve4 specitied In 3.2.6. Should be used as me standard output votLage
3.2.3 SettIng of tone controls
Unless otherwise stated, the tone controls that have an influence on the frequency characteristics shall be adiusted for a practically flat response characteristic at the volume control position specified br the measurement. If the volume control Is physiologically weighted (loudness control) and me compensation cannot be switched oft, it shall be set for minimum compensation effect and the standard output power obtained by adjusting the audio input level and this value stated with the results.
3.2.4 SettIng of stereo balance control
Unless otherwise specified, the balance control(s) shall be adjusted so that the output powers of the two channels are of the same value at the volume control position specified for measurement.