Electrical Adjustment - Panasonic PV-M1348 Service Manual

ELECTRICAL ADJUSTMENT

TEST EQUIPMENT
To do all of these electrical adjustments, the following equipment
is required.
1. Dual-Trace Oscilloscope
Voltage Range : 0.001 to 50V/Div.
Frequency Range : DC to 50MHz
Probes : 10:1, 1:1
2. NTSC Video Pattern Generator
3. DVM(Digital Volt Meter)
Voltage Range : 0.01 to 50V
4. MTS/SAP Signal Generator
(TV Multi-Channel Sound Modulator (U.S.A.))
5. Frequency Counter
Frequency Range : 0 to 150MHz
6. Plastic Tip Driver and Non-Metal Driver
7. Isolation Transformer (Variable)
8. VHS Alignment Tape (VFMS0003H6)
9. Degaussing Coil
10. White Pattern Generator
HOW TO READ THE ADJUSTMENT
PROCEDURES
CH1: TP2005
5V 5V
1 2
3
1. Connecting Point
3. Volts/DIV
5. Time/DIV
Fig. E1
CH1
CH2
CH2: TP2006
5ms 1
6
4 5
2. Volts/DIV
4. Connecting Point
6. Trigger Channel of
the Scope
1 : CH1
2 : CH2
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.)
Adjustment : R4901 (TV Stereo C.B.A.)
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) on the TV
Stereo C.B.A.
3. Set to TV mode, and then set to STEREO audio.
4. Adjust R4901 on the TV Stereo C.B.A. so that the signal
level is minimum.
Minimum
TP4202(R CH)
20mV
2-25
(Model: K)
1ms
Fig. E2