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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
2. MW Oscillator
3. FM IF
4. AM IF
5. MW aerial
bandpass circuit
(MW RF)
6. AF reject circuits
VC500
GRUNDIG Service
Preparation
FM
DC voltmeter to IC 506 Pin 6.
MW
DC voltmeter to IC 506 Pin 6.
FM, 98MHz
Signal generator 98MHz to aerial input.
Level abt. 100µV/40dBµV/75Ω, f
Distortion meter to Loudspeaker output.
MW
Sweep generator 450kHz to aerial inputs.
as low as possible, ∆f = 10kHz.
U
out
Oscilloscope to IC 500 Pin 4.
MW
Signal generator to aerial input.
U
<, m = 30%, f
= 1kHz.
a
mod
AF voltmeter to Loudspeaker output.
FM, 98MHz
Signal generator 98MHz to aerial input.
Level abt. 100µV/40dBµV/75Ω, f
AF voltmeter to Loudspeaker outputs.
F1
Frontend IC506
6
CF502
L500
IFT502
Digitized in Heiloo, Holland
Check at 108.0MHz for 8V
Check at 87.5MHz for 1.6V
With IFT502 set to 7.3V
Check at 531kHz for 1.1V
With F1 set for minimum distortion.
= 1kHz, dev. 75kHz.
mod
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.
= 19kHz.
mod
Main Board
IFT500
CF500
4
IC500
30/7/2014
Abgleichvorschriften / Adjustment Procedures
Procedure
±
1V.
±
0.4V.
±
0.2V at 1602kHz.
±
0.4V.
When replacing one of the ceramic
resonators, take care that the colour codes
of all resonators are the same.
IF (MHz)
IF Filter
IF Filter
Ident letter
10.6500
D
10.6750
B
10.7000
A
10.7250
C
10.7500
E
IC504
X504
LPF501
LPF500
Colour
black
blue
red
orange
white
2 - 3
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