Abgleichvorschriften / Adjustment Procedures
Varixx UMS 4200
2 - 2
GRUNDIG Service
Adjustment Procedures
Tuner
Test equipment:
Signal Generator, Oscilloscope, Digital Voltmeter
Adjustment
Preparation
Adjustment Procedure
1. AM Oscillator
2. AM IF
3. AM Pre Stage
4. FM Oscillator
5. FM Pre Stage
AM
;
Digital Voltmeter
to
Testpoint TP1
.
AM
;
Couple
Signal Generator 450kHz
via
Loop Antenna
;
Ue > 70dB
µ
V; f
mod
= 1kHz; m = 30%;
Oszilloscope
to
Loudspeaker Output
.
AM
;
Couple
Signal Generator
via
Loop Antenna
;
Ue > 40dB
µ
V; f
mod
= 1kHz; m = 30%;
Oszilloscope
to
Loudspeaker Output
.
FM
;
Digital Voltmeter
to
Testpoint TP1
.
FM
;
Signal Generator
to
FM Aerial Input
;
Ue = 20dB
µ
V; f
mod
= 1kHz; deviation = 75kHz;
Oszilloscope
to
Loudspeaker Output
.
Adjust with
T202
at
1602kHz
for
7.5V
±
0.5V
.
Adjust with
T201
for
AF Maximum
.
Adjust alternating with
MW COIL
(move) at
558kHz
and
with
VC201
at
1440kHz
for
AF Maximum
.
Adjust with
L203
(bend) at
108.0MHz
for
7.5V
±
0.5V
.
Adjust alternating with
L204
(bend) at
88.0MHz
and with
VC202
at
106.0MHz
for
AF Maximum
.
Adjust
L208
(bend) alternating at
88.0MHz
and at
108.0MHz
for
AF Maximum
(averaging).
Tape Deck
Test equipment:
Oscilloscope, Frequency Counter, Test Cassette 3150Hz/10kHz (e.g. 448A)
Adjustment
Preparation
Adjustment Procedure
1. Tape Speed
2. Azimuth
3. Bias Frequency
Frequency Counter
to
Loudspeaker Output
.
Play Test Cassette (3150Hz part).
Oszilloscope
to
Loudspeaker Output
.
Play Test Cassette (10kHz part).
Frequency Counter
to
CN302(-1)
.
Start recording.
Adjust
Motorpoti
for 3150Hz
±
10Hz.
Motorpoti
With
Head screw
A
adjust for
maximal
and
equal level
in both channels.
A
Adjust with
T360
for
60kHz
±
100Hz
.
