Transmitter Adjustment - Icom IC-718 Service Manual Addendum

Oct. 2007

5-3 TRANSMITTER ADJUSTMENT

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