Icom IC-718 - Transmitter Adjustment

1
5-3 TRANSMITTER ADJUSTMENT
ADJUSTMENT ADJUSTMENT CONDITION
MEASUREMENT
VALUE
ADJUSTMENT
POINT
UNIT LOCATION UNIT ADJUST
IDLING
CURRENT
(for pre-driver)
1• Display frequency : 14.10000 MHz
• Mode : USB
• RF power : Minimum (L)
• Mic gain : Minimum (0)
•
Disconnect J3601 (MAIN unit) and
preset R51, R56, R58, R62, R64
(PA unit) to counter clockwise.
• Transmitting
PA Connect a digital
multimeter to the CP1.
Set the voltage
between CP1 and
GND to 0.5 V.
PA R51
(for driver) 1 • Transmitting PA Connect an ammeter
(10 A) between the
power supply and
IC-718.
At the point where
the Tx current
increases 800 mA.
PA R56
2
At the point where the
Tx current increases
another 800 mA.
R58
(for fi nal amplifi er) 1 • Transmitting PA At the point where
the Tx current
increases 800 mA.
PA R62
2
At the point where the
Tx current increases
another 800 mA.
R64
After the "IDLING CURRENT" adjustment, recover the connection of J3601.
SWR
DETECTOR
1
• Display frequency : 14.10000 MHz
• Mode : USB
• RF power : Maximum (H)
•
Connect J4 (FILTER unit) to GND .
• Connect an audio generator to
[MIC] connector and set as;
Frequency : 1.5 kHz
Level : 30 mVrms
• Transmitting
Rear
panel
Connect an RF
power meter to [ANT]
connector.
100 W Front
panel
Mic gain
control
in the
"quick set
mode."
2 • Transmitting
FILTER Connect a digital
multimeter to J5.
Minimum voltage FILTER C17
After the "SWR DETECTOR" adjustment, recover the connection of J4.
TRANSMITTER
TOTAL GAIN
1• Display frequency : 14.10000 MHz
• Mode : USB
• RF power : Maximum (H)
• R2701 (MAIN unit) : Center
• Mic gain : Center (50)
• Connect an audio generator to
[MIC] connector and set as;
Frequency : 1.5 kHz
Level : 3 mVrms
• Transmitting
Rear
panel
Connect an RF
power meter to [ANT]
connector.
Maximum output
power
MAIN L106,
L151,
L301,
L302,
L303,
L501
2 • Transmitting 50 W R503
OUTPUT
POWER
1•
Display frequency : 14.10000 MHz
• Mode : USB
• RF power : Maximum (H)
• Mic gain : Center (50)
• Connect an audio generator to
[MIC] connector and set as;
Frequency : 1.5 kHz
Level : 30 mVrms
• Transmitting
Rear
panel
Connect an RF
power meter to [ANT]
connector.
100 W MAIN R1707
Ic APC 1 •
Display frequency : 3.55000 MHz
• Mode : USB
• RF power : Maximum (H)
• Mic gain : Center (50)
• Connect CP4002 (MAIN unit)
to GND.
• Connect an audio generator to
[MIC] connector and set as;
Frequency : 1.5 kHz
Level : 30 mVrms
• Transmitting
Rear
panel
Connect an ammeter
(30 A) between power
supply and the IC-718.
22 A MAIN R1720
After the "Ic APC" adjustment, recover the connection of CP4002.
Oct. 2007
TRANSMITTER ADJUSTMENTS for PA UNIT "B-5380I"