CCE HPS-1407, Service Manual, Page: 8 / 52

HPS-2007
7
2 . 1.4 Áudio frequency response for the stereo television set with tonality control
a) Repeat the above procedures (item 1.3) for the following additional conditions:
Condition Minimum Nominal Maximum Unit
Bass control in max. position 100Hz - - - dB
Treble control in the meddle. 10kHz - - - dB
Bass control in the min position. 100Hz - - - dB
Treble control in the meddle. 10kHz - - - dB
Bass contr. in the meddle post.. 100Hz - - - dB
Treble control int the min pos.. 10kHz - - - dB
Bass contr. in the meddle pos. 100Hz - - - dB
Treble contr in the max. pos.. 10kHz - - - dB
2.1.5 Channel separation in Stereo reception for the stereo television set
a) TV setup in PP condition.
b) Apply a 60dB
µ
V signal ( frequency and channel factory defined) with 88% video
modulation and audio stereo carrier modulation within the standard “MTS” (BTSC).
c) Connect an AC double voltmeter at the audio output L-R.
d) Adjust the volume control to max. and the tremble, bass and balance to middle position.
Note
:
ü
Disconnect the speakers for more comfortable work.
e) Adjust the stereo generator for left channel only – with 30% modulation of 300 Hz sine
wave and 7.5 kHz deviation.
f) Read the Double Voltammeter value Vac corresponding of Left and Right channel and
calculate the stereo separation trough the equate:
Sep
(300Hz) L
→
R
= 20 log (V
L
/V
R
)
g) Adjust the stereo generator for left channel only – with 30% modulation of 3kHz sine wave
and 7.5 kHz deviation.
Sep
(3kHz) L
→
R
= 20 log (V
L
/V
R
)
h) Repeat the procedures e, f and g, and now select Right channel only, at the same
conditions above mentioned.
Sep
(300Hz) R
→
L
= 20 log (V
R/
V
L
)
Sep
(3kHz) R
→
L
= 20 log (V
R/
V
L
)
Condition Minimum Nominal Maximum Unit
Sep
(300Hz) L
→
R
- - - dB
Sep
(3kHz) L
→
R
- - - dB
Sep
(300Hz) R
→
L
- - - dB
Sep
(3kHz) R
→
L
- - - dB