Pll And Transmitter Adjustments; Main Unit - Icom IC-T2H Service Manual

5-2 PLL AND TRANSMITTER ADJUSTMENTS

ADJUSTMENT ADJUSTMENT CONDITION
PLL LOCK 1 • Operating frequency : 146.000 MHz
VOLTAGE • Receiving
REFERENCE 1 • Operating frequency : 146.000 MHz
FREQUENCY • Transmitting
OUTPUT 1 • Operating frequency : 146.000 MHz
POWER • HIGH/LOW switch
• Connect the "JIG" to the [SP] jack.
• Transmitting
2 • HIGH/LOW switch
• Transmitting
1 • Operating frequency : 146.000 MHz
FM
DEVIATION • HIGH/LOW switch
• Connect an audio generator to the
[MIC] jack and set as :
1 kHz/90 mV
• Set an FM deviation meter as:
HPF
LPF
De-emphasis
Detector
• Transmitting

• MAIN unit

L11
PLL lock voltage
adjustment
MEASUREMENT
UNIT
MAIN
Top
panel
Top
: HIGH panel
: LOW
Top
: HIGH panel
: OFF
: 20 KHz
: OFF
: (P–P)/2
Bottom view
5 - 2
LOCATION
Connect a digital multi-
meter to the check
point LV.
Connect an RF power 146.000000 MHz
meter or a terminator
to the antenna con-
nector and loosely
couple a frequency
counter.
Connect an RF power 4.5 W [THA]
meter to the antenna 5.5 W [other]
connector.
Connect an FM devia-
tion meter to the
antenna connector
through an attenuator.
Top view
ADJUSTMENT
POINT
VALUE
UNIT ADJUST
1.40 V VCO L11
board
MAIN C68
Front
Push [
Panel
or [
switch
while
transmit-
1.0 W
ting.
R119
±4.5 kHz MAIN
C68
Reference frequency
adjustment
LV
PLL lock voltage
check point
R119
FM deviation
adjustment
]
]