Icom IC-M412 Service Manual page 18

5-2 ADJUSTMENT
ADJUSTMENT
ADJUSTMENT
LOCK VOLTAGE 1 • Channel
VERIFICATION • Receiving
(MAIN-RX)
(CH70-RX) 2 • Receiving
(CH16-TX) 3 • Channel
• Output power : Low
• Transmitting
REFERENCE 1 • Channel
FREQUENCY • Transmitting
TRANSMIT 1 • Channel
OUTPUT • Output power : High
POWER • Transmitting
DEVIATION 1 • Channel
• Output power : Low
• Transmitting
RECEIVE 1 • Channel
SENSITIVITY • Receiving
(MAIN-RX)
†
; The output level of the standard signal generator (SSG) is indicated as the SSG's open circuit.
• ADJUST&CHECK POINTS
R112
Transmit output power
adjustment point
R327
Deviation adjustment point
CP1
CH70-RX/CH16-TX
Lock voltage
check point
CONDITION
: 16 • Connect a Digital voltmeter to the CP2
(MAIN-A UNIT).
• Connect a Digital voltmeter to the CP1
(MAIN-A UNIT).
: 16 1) Connect an RF Power Meter to the antenna
connector.
2) Connect a Digital voltmeter to the CP1
(MAIN-A UNIT).
: 16 • Loose-couple a Frequency Counter to the
antenna connector.
: 16 • Connect an RF Power Meter to the antenna
connector.
: 16 1) Disconnect the cable from J4 (MAIN-A
UNIT).
2) Connect an Audio Generator and AC millivolt-
meter to the "MIC" line, and set as;
3) Connect a Modulation Analyzer to the
antenna connector through an attenuator.
: 16 1) Connect a Standard Signal Generator to
the antenna, and set as;
2) Connect a 4 Ω speaker to the external
speaker lead.
3) Connect a Digital voltmeter to the CP3
(MAIN-A UNIT).
R327
CP1
OPERATION
• Frequency : 1 kHz
• Level : 140 mV
• Frequency : 156.800 MHz
• Modulation : 1 kHz
• Deviation : ±3 kHz
• Level : +10 dBµ (−97 dBm)
R112
CP2
R214
C12
J4
Disconnect
5 - 2
ADJUSTMENT
POINT
–
C12
(MAIN-A UNIT)
R112
23–23.5 W
(MAIN-A UNIT)
R327
(MAIN-A UNIT) ±4.35 kHz
L38→L36→L39
(in sequence,
repeatedly)
L36
Receive sensitivity (MAIN-RX)
L38
adjustment points
L39
CP2
MAIN-RX lock voltage check point
C12
Reference frequency adjustment point
1
J4
SETTING;
• Frequency : 1 kHz
• Level : 140 mV
–
Audio generator
+
–
AC millivoltmeter
+
VALUE
1.1–2.1 V
(Verify)
1.0–2.0 V
(Verify)
156.800
MHz
±4.25 to
Maximum
voltage
5
[PTT]
"MIC"