Audio System Adjustment (Hdc1550); Frequency Adjustment - Sony HDC1000 Maintenance Manual

3-9. Audio System Adjustment (HDC1550)

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Be sure to perform "3-7. TONE Adjsutment" before
adjusting the audio system.

3-9-1. Frequency Adjustment

Preparation
1. Connect the oscilloscope to the spectrum analyzer as
shown below.
CH2 CH2
Probe
IN OUT
Oscilloscope
Adjustment procedure
2. Measuring equipment:
Spectrum analyzer
(via oscilloscope)
CENTER: 6.7 MHz
SPAN:
RBW:
Test point: TP106 (GND: E200)/TR-136 board
Adjusting point and specification:
Adjusting point
MIC 1 1LV102/TR-136 board
1LV103/TR-136 board
MIC 2
INCOM 1 1LV104/TR-136 board
INCOM 2 1LV105/TR-136 board
3-32
IN
Spectrum analyzer
3 MHz
30 kHz
Specification
A = 6.20 ± 0.01 MHz
B = 6.70 ± 0.01 MHz
C = 7.10 ± 0.01 MHz
D = 7.40 ± 0.01 MHz
1
2
A B C D
3
3. Change the SPAN of the spectrum analyzer to 50 KHz,
and RBW to 300 Hz.
4. Adjust the frequency at each waveform peak while
changing the CENTER of the spectrum analyzer.
Measuring equipment:
Spectrum analyzer
(via oscilloscope)
CENTER: 6.2 MHz (MIC 1)
SPAN:
RBW:
Test point: TP106 (GND: E200)/TR-136 board
Adjusting point and specification:
Spectrum
analyzer
CENTER
MIC 1 6.2 MHz
MIC 2 6.7 MHz
INCOM 1 7.1 MHz
INCOM 2 7.4 MHz
A
B
E2
TP605
S1
RV761
TP604
RV601
RV602
TP801
RV801
TP401
RV721
TP721
E1
TP603
TR-136 BOARD (SIDE A)
6.7 MHz (MIC 2)
7.1 MHz (INCOM 1)
7.4 MHz (INCOM 2)
50 KHz
300 Hz
Adjusting Specification
point/
TR-136 board
6.200 ± 0.005 MHz
1LV102
6.700 ± 0.005 MHz
1LV103
7.100 ± 0.005 MHz
1LV104
7.400 ± 0.005 MHz
1LV105
Waveform peak
C
D
LV210
LV102
LV209
TP209
RV102
LV208
LV207
LV103
TP207
LV204
RV103
LV203
TP203
LV105
LV206
LV205
RV105
TP106
E200
LV202
TP202
TP201
LV104
RV104
LV101
TP602
TP601
HDC1000/V1(E)
RV204
TP210
RV203
TP208
RV201
TP204
RV202
TP206
TP205
E4