Sanyo SRT-4040 Service Manual page 10

2-2. VIDEO CIRCUIT ADJUSTMENT
Before making the following adjustments, complete the adjustments described in section 2-1. "Servo Circuit."
2-2-1. TEST EQUIPMENT AND STANDARDS REQUIRED
Color Bar Signal Generator
Frequency Counter
Oscilloscope
Oscilloscope Probe
Blank Tape
Notes :
• Self-recording means "Record the video signal and play
back the just-recorded portion."
2-2-2. COMB FILTER ADJ.
Measuring Point Measuring Equipment Adj. Condition
TP102 Color bar generator
Oscilloscope
Adj. Location
VR111 (COMB)
1. Connect the color bar generator (Color bar signal with 100
% white level) to the VIDEO IN terminal.
2. Connect the Oscilloscope to TP102.
3. Adjust VR111 (COMB) so that the chroma level becomes a
minimum.
NTSC color bar signal with 100% white level (EIA color bar signal),
monoscope signal
Vertical sensitivity
Bandwidth
Input capacity
Covering frequency
VHS cassette tape
E-E mode
Adj. Value
minimum
TP152
TP151
VR151
TP153
VD-1 PWB (Parts side)
: 5 mV/DIV, external trigger
: more than 10 MHz
: less than 25 pF (10:1)
less than 40 pF (1:1)
: DC~40 MHz (10:1)
DC~30 MHz (10:1)
2-2-3. 2H DELAY LEVEL ADJ.
Measuring Point Measuring Equipment Adj. Condition
Oscilloscope
TP151
Color bar generator
or VIDEO OUT
Adj. Location
VR151 (2H-DL)
1. Terminate TP151 (or VIDEO OUT) and ground with a 75 Ω
resistor or connect the monitor TV to the VIDEO OUT ter-
minal.
2. Connect the color bar generator (monoscope signal) to the
VIDEO IN terminal.
3. Record the monoscope signal on the blank tape.
4. Play back of the just-recorded portion.
5. Adjust VR151 (2H-DL) so that the luminance signal level of
switching alternately becomes the same or no flicker by
monitor TV.
– 10 –
Self-recording
(8H) mode
STILL mode
Blank tape
Adj. Value
Fig. 2-1-1