HPS-2007
8
2.1.6
Output and distortion level of S.A.P. signal 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 Stereo / S.A.P audio signal carrier in accordance of standard “MTS”
(BTSC).
c)
Connect na AC volt-distortion-meter at the Left channel (pin 27 – IC604) small signal
output.
Note
:
ü
Disconnect the speakers for more comfortable work.
d)
Adjust the Stereo/SAP generator for 400 Hz sine wave and 100% modulation.
e)
Active the SAP function in the Test Television.
f)
Read Vac at the AC volt-distortion-meter.
g)
Repeat all above procedures, connecting the volt-distortion-meter at the Right channel (pin
21 – IC604) small signal audio output.
Minimum
Nominal
Maximum
Unit
Output Level
-
490
-
mV
AC
Distortion (THD)
-
-
2
%
2.1.7
AM Rejection
a)
TV setup in PP condition.
b)
Connect at the IF sound input a FM generator adjust to 4.5 MHz modulated with 400 Hz
sine wave and +/- 25 kHz deviation and 90 dBuV level.
c)
Connect na AC voltmeter in the audio detector output (after the emphasis circuit) and read
the VFM tension.
d)
Connect at the IF sound input a AM generator pre-adjust to 4.5 MHz 40% modulated with
400 Hz sine wave, and 90 dBuV level.
e)
Read the Vam value in the voltmeter.
AM rejection will now be calculated by the equation:
Rej
AM
= 20 log( V
FM
/V
AM
)
Note
:
ü
Because this parameter is designed to define only the one circuit TV
perform, the startup conditions adjust and what’s circuits will be
supplied, it will be defined separately for each one model
.
Minimum
Nominal
Maximum
Unit
30,00
40,00
60,00
dB
