Panoramic TVP-2914, Руководство по обслуживанию

Страница: 7 / 52

TVP-2914
6
2.1.3 Audio frequency response in TV’s without tone control
a) TV adjustment condition:
ü
Balance center
ü
Bass center
ü
Treble center
b) Connect a color bar generator (PAL-M system) to video-in.
c) Connect to the audio input TV - an audio generator adjust to 500 mVac
level, and sine wave 1kHz.
d) Connect to the output power amplifier a resistive load with the same value
of the impedance speaker.
e) Connect na AC voltmeter over the resistive load and adjust volume control
until obtain 1 Vac
) .
f) Realign the audio generator to 100 Hz sine wave at the same level ( 500
mVac).
g) Read the new voltage in the resistive load and calculate the change in dB
through next equation:
A
(100Hz)
=20 log
(VL/VREF)
The result is defined in “Decibel units “
h) Readjust the audio generator frequency to 10 kHz at the same level.
i) Read the new voltage Vh at the resistive load and calculate the change in
dB through the next equation:
A
(10kHz)
=20logV
H
/V
REF
Condition Minimum Nominal Maximum Unit
100Hz 2,00 6,00 10,00 dB
10kHz 0,00 +4,00 +8,00 dB
2 . 1.4 Áudio frequency response for the stereo television set with tonality
control
a) Repeat the above procedures (item 3) for the following additional
conditions:
Condition Minimum Nominal Maximum Unit
Bass control in max. position 100Hz +16,00 +20,00 +25,00 dB
Treble control in the meddle. 10kHz -5,00 +7,00 +10,00 dB
Bass control in the min position. 100Hz -10,00 -3,00 +3,00 dB
Treble control in the meddle. 10kHz -5,00 +7,00 +10,00 dB
Bass contr. in the meddle post.. 100Hz +4,00 +10,00 +15,00 dB
Treble control int the min pos.. 10kHz -15,00 -5,00 +10,00 dB
Bass contr. in the meddle pos. 100Hz +4,00 +10,00 +15,00 dB
Treble contr in the max. pos.. 10kHz +10,00 +15,00 +25,00 dB