Pll Adjustments - Icom IC-M502 Service Manual

5-2 PLL ADJUSTMENTS

ADJUSTMENT ADJUSTMENT CONDITION
LOCK 1 • Operating channel : ch16
VOLTAGE • Receiving
2 • Operating channel : ch116
• Receiving
3 • Operating channel : ch16
• Output power
• Transmitting
4 • Operating channel : ch116
• Output power
• Transmitting
REFERENCE 1 • Operating channel : ch16
FREQUENCY • Output power
• Connect an RF power meter or a
50 Ω dummy load to the antenna
connector.
• Transmitting
L10
Lock voltage
adjustment for TX
L13
Lock voltage
adjustment for RX
MEASUREMENT
UNIT
MAIN Connect a digital
multi-meter or oscil-
loscope to check
point CP1.
Connect a digital
: Low multi-meter or oscil-
loscope to check
point CP2.
: Low
Rear Loosely couple the
: Low Panel frequency counter
to the antenna con-
nector.
5 - 2
VALUE
LOCATION
3.5 V
4.5–6.0 V
2.5 V
2.5–3.5 V
156.8000 MHz
ADJUSTMENT
POINT
UNIT ADJUST
MAIN L13
Verify
L10
Verify
MAIN C70
CP2
Lock voltage
check point for TX
C70
Reference frequency
adjustment
CP1
Lock voltage
check point for RX