IEC 60107-4:1999 pdf download.Recommended methods of measurement on receivers for television broadcast transmissions
1 Scope
The methods of measurement described in this standard apply to television receivers
designed for the reception of television broadcast transmission using the two-carrier FM-
system, for the associated sound ( * ITU-R Recommendation BS.707-3, annex 1 ).
2 Object
The object of this standard is to standardize the methods of measurement for the more
important electrical characteristics of receivers, within the scope of this part of the standard.
3 Definition of modes
The two-carrier system offers the possibility of audio transmission using three different modes
of operation:
dual sound:transmission of a left and right channel sound signal
stereophonic:transmission of a monaural signal.
monaural:transmission of two independent sound signals
4 Pilot signal
The pilot signal, which is transmitted on the second sound carrier, enables the receiver to
detect the mode of operation under which transmission takes place. For this purpose the
following identification frequencies are modulated on an auxiliary carrier (pilot carrier):
5 Identification signal modulation
Identification signal modulation denotes that modulation component of the second sound
carrier which is used to switch the decoder incorporated in the receiver into one of the three
modes of operation.
6 Modes of operation
The following modes of operation are used for audio-reproduction.
6.1 Dual-sound mode
In the dual-sound mode, two independent monophonic sound signals are transmitted. It is
possible to reproduce the signal of either channel alone, or those of both channels together.
The first sound carrier transmits the audio signal which is compatible with monaural receivers,
the second sound carrier transmits the additional monaural signal.
6.2 Stereophonic mode
A stereophonic sound signal is reproduced in the stereophonic mode. Here the first sound
carrier transmits the compatible monaural signal while the second sound carrier transmits the
right channel signal. Both the left and the right channel signals are then restored by means of
a dematrixing circuit.
6.3 Monaural mode
In the monaural mode a monaural sound signal is reproduced by the receiver. The second
sound carrier is modulated with the same monaural signal as the first sound carrier.
7 General conditions
Unless otherwise stated, measurements shall be carried out under the conditions described in
IEC 601 07-1 and IEC 601 07-2.
8 Standard output power and voltage
8.1 Standard output power for loudspeaker
The standard output power shall be a power 1 0 dB below the rated output power (see 3.1 of
IEC 601 07-2). 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), 1 7 dB(mW) and 7 dB(mW), respectively. In all cases,
the value chosen shall be stated with the results.
8.2 Standard line output voltage
The standard output voltage at a line output terminal shall be 500 mV r.m.s. at 1 kHz when
terminated with a resistor equal to the rated load impedance.
NOTE – If the output is not adjustable, the output voltage when the standard r.f. television signal is applied to the
receiver at the r.f. input signal level specified in clause 1 2 should be used as the standard output voltage.
9 Setting of tone controls
Unless otherwise specified, the tone controls or other controls that have an influence on the
frequency response characteristics shall be adjusted for a practically flat response
characteristic at the volume control position specified for the measurement. If the volume
control is physiologically weighted (loudness control) and the compensation cannot be
switched off, it shall be set for minimum compensation effect and the reference output power
obtained by adjusting the modulation input level and this value stated with the results.
Switchable noise reduction and electronic base-widening circuits or the like shall be switched
off. If the tone controls are neither switchable nor adjustable, this shall be indicated with the
results.
10 Setting of stereo balance control
For the balance setting, the receiver aerial input is provided with an r.f. signal with
stereophonic identification. Both audio channels are modulated with 1 000 Hz and a
modulation factor of 30 %.
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.
IEC 60107-4:1999 pdf download
