759 Inf Rared Receiver - Icom IC-2710H Service Manual

1 0-5 EX-1 759 I N F R A R E D R E C E I V E R
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R2
22k
R
R14 16
10k lk
1 O OV
4
2 7V
3 4
7V
03
155353
1 2 2V
2 1 6V
3 2 SV
4 2 5V
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2 S OV
C62 C63 C64 C65
0.001 47p 0.001 0.001
1 . 3.7V 3 3 7V
2 3.7V 4 3 7V
I N F R A R E D R E C E I V E R ADJ U ST M E NT
ADJUSTMENT ADJUSTMENT CONDITIONS
SQU ELCH 1 • Connect an SSG to the J1 via the coupling
capacitor (0.01 µF), and set as:
Frequency 455 kHz
Level 3.2 µV* (-97 dBm)
Modulation 1 kHz
±
Deviation 3.5 kHz
2 • Set an SSG level : 7 . 1 µV* (-90 dBm)
1 (-82
BUSY • Set an SSG level : 1 8 µV* dBm)
2
• Set an SSG level OFF.
RECTANGLE 1 • Set an SSG as:
WAVES
Level 3.2 mV* (-37 dBm)
±
Deviation 0.3 kHz
*This output level of a standard signal generator (SSG) is indicated as the SSG's open circuit.
R52
2.2M
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TX ON
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1 0 1V 3. 1 V
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2 0 1V 4 0 l V
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TX ON 4:
1 8 9V 3 8 6V
2. 8 9V • I
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ADJUSTMENT
MEASU REMENT
VALU E
UNIT LOCATION UNIT
MAIN Connect an oscil- At the point MAIN
where the signal
loscope to CP1 .
just becomes
high.
Low
MAIN Connect an oscil- High MAIN
loscope to CP2.
Low
1 kHz MAIN
MAIN Connect an oscil-
loscope to CP3.
1 0 - 5
BOARD LAYOUT
•
TOP VIEW
WGND
WMIC
WMICE
NC
NC
NC
CP1
SQUELCH
'"
check point
J1
" '
2.2µH W 1
BOTTOM VIEW
POINT
ADJUST
R23
Verify
R 1 8
Verify
R59
R59
R23 R 1 8
RECTANGLE WAVES BUSY adjustment
SQU ELCH adjustment
adjustment
CP3
RECTANGLE WAVES
check point