Adjustment Procedures
GV 67 …, GV 69 …
8
GRUNDIG Service
Adjustment
Preparation
Adjustment Procedure
1. VXO Frequency,
C2306
(XO)
2. Chroma Writing
Current,
R3273
(CHSP)
3. Pilot Burst Amplitude,
R3295
(PBA)
4. 627kHz Comb Filter,
R3167
(CF)
Frequency Counter: ................................................... MP
41
Playback (PAL signal)
Oscilloscope: .............................................................. MP
43
Feed in and record a colour bar test pattern (PAL).
Oscilloscope: .............................................................. MP
43
Feed in a colour bar test pattern (PAL) .
EE mode with loaded S-VHS cassette.
Oscilloscope: .............................................................. MP
42
Trigger: ................................. HI pulse, plug contact 1524-(11)
Play back a recording made on the machine itself (red test
signal).
With C2306
(XO)
set the frequency to 4.433619MHz.
With R3273
(CHSP)
set the amplitude of the red component to
150mV
PP
.
With R3295
(PBA)
set the pilot burst amplitude to 110% of the
PAL burst amplitude.
With R3167
(CF)
set the signal as shown in the oscillograms
below.
Incorrect
CORRECT
Incorrect
200
µ
s/cm
2. Transcoder Board – Chrominance (SF)
Test equipment / aids: Oscilloscope and Frequency Counter with 10:1 Test Probe, Digital Voltmeter, Colour Generator.
Service work after changing the …
… Transcoder Board: –
… IC7270: Adjustment no. 1, 2, 3
… IC7175: Adjustment no. 4
