Pll And Transmitter Adjustments - Icom IC-2800H Service Manual

5-2 PLL AND TRANSMITTER ADJUSTMENTS

ADJUSTMENT ADJUSTMENT CONDITION
PLL LOCK 1 • VHF displayed freq. :
VOLTAGE
• Receiving
PLL 1 • UHF displayed freq. :
REFERENCE 450.000 MHz
440.000 MHz
FREQUENCY
• Output power : Low
• Transmitting
UHF 1 • UHF displayed freq. :
OUTPUT 445.000 MHz
435.000 MHz
POWER
• Output power : High
• Transmitting
2 • Output power : Low
• Transmitting
3 • Output power : Mid-L
• Transmitting
4 • Output power : Mid-H
• Transmitting
1 • VHF displayed freq. :
VHF
OUTPUT 145.000 MHz
POWER 146.000 MHz
• Output power : High
• Transmitting
2 • Output power : Low
• Transmitting
3 • Output power : Mid-L
• Transmitting
4 • Output power : Mid-H
• Transmitting
FREQUENCY 1 • UHF displayed freq. :
445.000 MHz
DEVIATION
435.000 MHz
• Output power : Low
• Connect an audio generator to
the [MIC] connector and set as:
1 kHz/ 80 mV
1 kHz/ 20 mV
• TONE : OFF
• Set an FM deviation meter as:
HPF : 50 Hz
LPF : 20 kHz
De-emphasis: OFF
Detector
• Transmitting
2 • VHF displayed freq. :
145.000 MHz
146.000 MHz
• Output power : Low
• Transmitting
3 • IF bandwidth
• Transmitting
MEASUREMENT
UNIT
MAIN
145.000 MHz
Rear
[USA] panel
other
Rear
[USA] panel
other
Rear
[EUR] panel
other
Rear
[USA] panel
other
[USA]
other
: (P–P)/2
[EUR]
other
: Narrow
[EUR, ITA] only
5 - 2
LOCATION
Connect a digital 1.65 V
multi-meter or oscil-
loscope to the
check point CP-LV.
Loosely couple the 450.0000 MHz [USA]
frequency counter 440.0000 MHz other
to the antenna con-
nector.
Connect an RF 35 W
power meter to the
antenna connector.
2–7 W
8–15 W
16–24 W
Connect an RF 50 W
power meter to the
antenna connector.
2–7 W
8–15 W
16–24 W
Connect an FM ±4.8 kHz
deviation meter to
the antenna con-
nector through an
attenuator.
±4.8 kHz
±2.0–±2.8 kHz
ADJUSTMENT
POINT
VALUE
UNIT ADJUST
MAIN
MAIN
MAIN
MAIN
MAIN
L2
C84
R121
Verify
R119
Verify
R78
R2
Verify