Icom IC-R7000 Service Manual page 23

6·2 PLL ADJUSTMENT
INSTRUMENTS REQUIRED CONNECTIONS
(1) FREQUENCY COUNTER
• FREQUENCY RANGE : 0.1 MHz-1.3GHz
•ACCURACY
: BETTER THAN ± 1 ppm
FREQUENCY
11
RF VOLT-
I I
OSCILL0·
11
VOLT-
• SENSITIVITY
: 100mV OR BETTER
COUNTER METER
SCOPE
METER
(2) RF VOLTMETER
!TO J6
• MEASURING RANGE : AT LEAST 500MHz
!To R139
(3) OSCILLOSCOPE
TO L22, L35
• FREQUENCY RANGE : DC-50MHz
TO J6, J2
B
• MEASURING RANGE : o.01-10v
::-
(4) VOLTMETER
• INPUT IMPEDANCE : 50k0/DC OR BETTER
MEASUREMENT
ADJUSTMENT
POINT
ADJUSTMENT ADJUSTMENT CONDITIONS VALUE
UNIT LOCATION
UNIT ADJUST
LO (36MHz) 1 •Mode: any PLL Connect an Maximum (More than
PLL
L29, L30
OUTPUT oscilloscope to 100mVp-p)
LEVEL R139.
MULTIPLIER
1 • Display freq.: 249.9999 MHz
Connect a
Minimum (5-6V)
L18,L19,
(Q10, Q11)
voltmeter to L22. L20, L21,
OUTPUT
L40
LEVEL
MULTIPLIER 1 • Display freq.: 250.0000 MHz Connect a Minimum (5-6V) L31, L32,
(Q16, Q18) voltmeter to L35. L33, L34
OUTPUT
LEVEL
2nd LO
1 •Display freq.: 512.0000MHz Connect a Maximum L41, L42,
OUTPUT spectrum analyzer
(Approx. OdBm/0.22V)
L43, L44,
LEVEL or RF voltmeter to
L49
J6.
2 •Display freq.: 511.9999MHz L46, L48
NOTE: If measured value is not within -2dBm-+3dBm (0.18V-0.32V), repeat steps 1 and 2.
2nd LO 1 • Display freq.: 511.9999 MHz PLL Connect a 768.0000 MHz
PLL
L39
OUTPUT frequency counter
FREQUENCY
2 • Display freq.: 512.0000 MHz
to J6.
256.0000 MHz Verify
1st LO
1 •Mode: FM Connect a 923.7000MHz R58
OUTPUT •Display freq.: 145.0000 MHz frequency counter
FREQUENCY to J2.
2 •Display freq.: 149.9999MHz 923.6999 MHz R49
NOTE: Repeat steps 1 and 2.
3 •Mode: SSB PLL Connect a 923.6985 MHz PLL R22
• USB/LSB SELECTOR SWITCH: frequency counter
LSB to J2.
•Display freq.: 145.0000MHz
4 • USB/LSB SELECTOR SWITCH: 923.7015MHz R21
USB
•Display freq.: 145.0000 MHz
6-2