Transmit Adjustment - Icom IC-M422 Service Manual

5-3 TRANSMIT ADJUSTMENT

ADJUSTMENT ADJUSTMENT CONDITION
OUTPUT 1 • Channel
POWER • Output power : High
• Transmitting
FREQUENCY 1 • Channel
DEVIATION • Output power : Low
• Connect an audio generator to the pin 28
of J4 (MAIN UNIT) and set as;
Frequency
Level
• Set the FM deviation meter as;
HPF
LPF
De-emphasis: OFF
Detector
• Transmitting
R112
Output power adjustment
R327
Frequency deviation
adjustment
UNIT
: CH16 (156.800 MHz) Rear
Panel
: CH16 (156.800 MHz) Rear
Panel
: 1 kHz
: 30 mV
: OFF
: 20 kHz
: (P−P)/2
Audio generator
AC millivoltmeter
5 - 3
MEASUREMENT
OPERATION
Connect an RF power
meter to the antenna
connector.
C o n n e c t a n F M ±4.25–4.35 kHz MAIN
deviation meter to the
antenna con-nector
through an attenuator.
29
J4
28
+
–
+
–
ADJUSTMENT
POINT
VALUE
UNIT ADJUST
23–23.5 W MAIN R112
R327