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UMS 11 ... UMS 12-S
GB
Adjustment Procedures
1. Tuner
Measuring instruments:
Standard/sweep signal generator, Oscilloscope, Distortion meter, DC voltmeter, AF voltmeter
Service works after replacing the front end: Alignment no. 3
The front end is a completely adjusted module. Only the IF filter is to be tuned to the IF amplifier.
Alignment
1. FM Oscillator
FM
DC voltmeter to IC 506 Pin 6.
2. MW Oscillator
MW
DC voltmeter to IC 506 Pin 6.
3. FM IF
FM, 98MHz
Signal generator 98MHz to aerial input.
Level abt. 100µV/40dBµV/75Ω, f
Distortion meter to Loudspeaker output.
4. AM IF
MW
Sweep generator 450kHz to aerial inputs.
as low as possible, ∆f = 10kHz.
U
out
Oscilloscope to IC 500 Pin 4.
5. MW aerial
MW
bandpass circuit
Signal generator to aerial input.
(MW RF)
U
<, m = 30%, f
a
AF voltmeter to Loudspeaker output.
6. AF reject circuits
FM, 98MHz
Signal generator 98MHz to aerial input.
Level abt. 100µV/40dBµV/75Ω, f
AF voltmeter to Loudspeaker outputs.
Frontend IC506
VC500
L500
GRUNDIG Service
Preparation
= 1kHz, dev. 75kHz.
mod
= 1kHz.
mod
= 19kHz.
mod
Main Board
F1
6
IFT500
CF502
CF500
4
IC500
IFT502
Abgleichvorschriften / Adjustment Procedures
Procedure
±
Check at 108.0MHz for 8V
1V.
±
Check at 87.5MHz for 1.6V
0.4V.
±
With IFT502 set to 7.3V
0.2V at 1602kHz.
±
Check at 531kHz for 1.1V
0.4V.
With F1 set for minimum distortion.
With IFT500 set for maximum and symmetry.
With L500 set for maximum at 603kHz.
With VC500 set for maximum at 1404kHz.
Repeat alignments.
Align with LPF500 at the right channel, resp. with LPF501
at the left channel for minimum.
When replacing one of the ceramic
resonators, take care that the colour codes
of all resonators are the same.
IF (MHz)
10.6500
10.6750
10.7000
10.7250
10.7500
IC504
LPF501
LPF500
IF Filter
IF Filter
Ident letter
Colour
D
black
B
blue
A
red
C
orange
E
white
X504
2 - 3
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