Grundig GV 500 SV/1 Serviceanleitung Seite 45

2.2 Family Board – Frontend (FV)
Test equipment: Oscilloscope with 10:1 Test Probe, Voltmeter, Colour Generator
Service work after replacing the Tuner: Adjustment no. 2
Adjustment
1. Vision Demodula- Feed in 38.9MHz / 100mV
tor Circuit, F5725 Voltmeter: ..................................................... IC7720-(15)
EE-mode.
2. Delayed AGC Feed in a PAL white test pattern with sound carrier (without
Voltage, R3742 sound modulation, UHF-range, Ch24, 67dBµV aerial signal)
into the warmed-up VCR.
Oscilloscope: ......................................... Tuner 1701-(17)
EE-mode.
2.3 Family Board – Video/Chroma (VS)
Test equipment: Oscilloscope with 10:1 Test Probe, Frequency Counter, Colour Generator
Service work after replacing the Family Board: Adjustment no. 3
Adjustment
1. Frequency Frequency counter: ............................................ 1911-(2)
Deviation Sync AV recording (do not feed in an signal).
Value, R3057
2. Chroma Writing Connect IC7051-(2) to +5V.
Current, R3038 Oscilloscope: ...................................................... 1911-(2)
Feed in a PAL red raster test pattern with 75% saturation
(ratio burst: chroma = 1 : 2.2).
AV recording.
3. FM-Reference Load a video cassette and select the input signal source.
Level Adjustment Call up the Service Function with the remote control handset:
for ACC (Automa-
– Press the button "CODE", enter the code number
4 9 3 4 and press the G button.
tic Contour
Control) plus – Press the button "CODE", enter the code number
4 9 3 8 and press the G button.
Studio Quality
2.4 Family Board – Standard Sound / Audio Linear (AL)
Test equipment / aids: AF Millivoltmeter, AF Generator, Video Cassette of reputable brand.
Service work after replacing the Family Board, the RP-Head or the Erase-Head: Adjustment no. 1.1, 3
Adjustment
1. Erase Frequency, Frequency counter: ............................................ 1918-(1)
F5603 Record
1.1 Bias, R3618 AF millivoltmeter: ................................................... R3600
Record
1.2 Frequency – Connect IC7601-(10) via 270Ω resistor to ground.
Response Test – Feed in a CCVS signal via EURO-AV1 socket, contact 20.
– Feed an audio signal of 200mV
generator to the EURO-AV1 socket, contact 2 or 6.
– Make a recording of 400Hz and 8kHz each of 1 min at
least. Afterwards play back these recordings.
– Connect an AF millivoltmeter (oscilloscope) to EURO-AV1
socket, contact 1 or 3.
2. Full Track Erase Frequency counter: ............................................ 1919-(2)
Frequency, L5604 Record
(Only for sets with
dubbing)
GRUNDIG Service
Preparation
into the tuner output 1701-(17).
PP
Preparation
Preparation
(480mV ) from the AF
rms PP
Abgleich / Adjustment Procedures
Adjustment Procedure
Set the voltage with F5725
(AFC)
Set the amplitude with R3742
(AGC)
Adjustment Procedure
Set frequency with R3057
(Sync. Frequ.)
Set Chroma signal with R3038
(PAL Curr.)
of the FM-signal).
Disconnect IC7051-(2) from +5V.
The machine automatically records the input signal and
then plays it back. On completion of the adjustment the
video recorder switches to stand-by.
Adjustment Procedure
With F5603 set the reading on the frequency
(Erase Oscillator)
±
counter to 70kHz 10kHz.
Set the voltage drop across R3600 with R3618
15mV .
rms
Check the frequency response.
The voltage ratio of 400Hz to 8kHz must not be higher than
1:0.7 or 0.7:1 (±3dB). If the voltage ratio exceeds these
limits, the bias must be altered:
To increase the playback voltage at 8kHz: Reduce "BIAS".
To reduce the playback voltage at 8kHz: Increase "BIAS".
Remove the 270Ω resistor between IC7601-(10) and
ground.
With F5604 set the reading on the frequency
(Dub Oscillator)
±
counter to 70kHz 10kHz.
±
to 2.5V 0.2V.
to 550mV +0/-50mV.
PP
±
to 3.8MHz 10kHz.
to 71mV (-12.5dB
PP
to
(BIAS)
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