Pll Unit; Bottom View Of The Transceiver - Icom IC-756PROIII Service Manual

PLL ADJUSTMENTS—continued
ADJUSTMENT ADJUSTMENT CONDITION
S2LO
1 • Display freq.
OUTPUT
• Receiving
LEVEL
MARKER
1 • Display freq.
OUTPUT
• Receiving
LEVEL

• PLL unit

PLL unit

Bottom view of the transceiver

LVB
VCO-B lock voltage
check point
P651
1LO-B output level
check point
C508
C528
VCO-B
lock voltage
adjustment
C558
C578
C454
LPL-B lock voltage
adjustment
LPB
LPL-B lock voltage
check point
P901
S2LO output level
check point
P801
3LO output level
check point
P701
S3LO output level
check point
MEASUREMENT
UNIT
: Any PLL
: Any PLL
4 - 3
LOCATION
Connect an RF volt- –3 dBm or more
meter to the check
point P901.
Connect an oscil- 4 Vp-p or more
loscope to the check
point P851.
ADJUSTMENT
POINT
VALUE
UNIT ADJUST
R33
Reference
frequency
adjustment
LVA
VCO-A lock voltage
check point
P361
1LO-A output level
check point
C278
C258
VCO-A
lock voltage
adjustment
C228
C208
C154
LPL-A lock voltage
adkustment
P851
Marker output level
check point
LPA
LPL-A lock voltage
check point
L52
Reference
L81
frequency
adjustment
L82
P81
Reference frequency
check point
Verify
Verify