Panasonic PV-M2738 Operating, Руководство по обслуживанию

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2-27
1ms
Minimum
20mV
TP4202(R CH)
SEPARATION ADJUSTMENT
Purpose:
To separate the L and R Channels of Stereo Signal.
Symptom of Misadjustment:
The L and R Channels of Stereo Signal will not be separated
properly resulting in no stereophonic effect.
Test Point : TP4202 (TV Stereo C.B.A.: Model A)
(Hi-Fi Audio C.B.A.: Model B, C)
Adjustment : R4901 (TV Stereo C.B.A.: Model A)
R4951 (Hi-Fi Audio C.B.A.: Model B, C)
Specification: minimum level
INPUT
: Antenna Input Terminal
MTS (ONLY L CH)
300Hz +/- 5Hz
14% or 7% Modulating
Mode : STEREO audio (TV)
Equipment : Oscilloscope, MTS/SAP Signal Generator
1. Connect the RF OUTPUT of the MTS/SAP Signal
Generator to the Antenna Input Terminal.
2. Connect the Oscilloscope to TP4202 (R CH).
3. Set to TV mode, and then set to STEREO audio.
4. (Model: A)
Adjust R4901 (SEPARATION ADJ) so that the signal
level is minimum.
(Model: B, C)
Adjust R4951 (SEPARATION ADJ) so that the signal
level is minimum.
Fig. E3
1
8
P4201
GND
4 pin
FM VCO ADJUSTMENT
Purpose:
To set VCO free run frequency.
Symptom of Misadjustment:
Even when stereophony is received, only monaural sound
will be output.
Test Point : Pin 4 of P4201,
TP9201 (TV Stereo C.B.A.: Model A)
(Hi-Fi Audio C.B.A.: Model B, C)
Adjustment : R9206 (TV Stereo C.B.A.: Model A)
(Hi-Fi Audio C.B.A.: Model B, C)
Specification: 38.05KHz +/- 50Hz
Input
: ----------
Mode : STEREO audio (FM Radio)
Equipment : Frequency Counter
1. Turn the unit "ON."
2. Set to FM Radio mode, and then set to STEREO audio.
3. Turn the unit "OFF."
4. Disconnect Connector PK2 on the TV Main C.B.A.
5. Connect Pin 4 of P4201 to GND.
Fig. E4-1
6. Connect TP9201 to GND through a resistor (3.3K ohm).
Then, connect Frequency Counter to TP9201.
Fig. E4-2
7. Adjust R9206 (FM VCO) so that the frequency is 38.05KHz
+/- 50Hz.
8. After this adjustment, connect Connector PK2 and remove
the GND Wire and resistor (3.3k ohm) which were connected
in step 5 and 6.
GND
TP9201
Frequency Counter
3.3k
Ω