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29
5
RECEIVE AND TRANSMIT
The AH-4 matches the IC-718 to a long wire antenna
more than 7 m/23 ft long (3.5 MHz and above).
• See p. 14 for connection.
• See the AH-4 instruction manual for AH-4 installa-
tion and antenna connection details.
NEVER operate the AH-4 without an antenna wire.
The tuner and transceiver will be damaged.
NEVER operate the AH-4 when it is ungrounded.
Transmitting before tuning may damage the trans-
ceiver. Note that the AH-4 cannot tune when using a
1⁄2
λ
long wire or multiple of the operating frequency.
TUNER OPERATION
• Tuner type setting (p.46)
q
Push [PWR] for 1 sec. to turn power OFF.
w
While pushing and holding [SET], push [PWR] to
turn power ON.
e
Push [UP
Y
] or [
Z
DN] one or more times to select
[TUNER].
r
Rotate the main dial to select “4”.
• AH-4
AUTOMATIC ANTENNA TUNER
is selected.
y
Push [PWR] for 1 sec. to turn power OFF.
u
Push [PWR] to turn power ON again.
• MANUAL TUNING
q
Set the desired frequency in an HF band.
• The IC-718 will not transmit outside of the ham bands,
the AH-4 tuner will tune all frequencies 3.5 to 30 MHz.
w
Push and hold [TUNER] for 1 sec.
• “
” blinks and “CW” appears while tuning.
e
“
”
lights constantly when tuning is complete.
• When the connected wire cannot be tuned, the “
”
goes out, the AH-4 is bypassed and the antenna wire is
connected to the antenna connector on the transceiver
directly.
r
To bypass the AH-4 manually, push [TUNER].
CONVENIENT
• PTT tune function
The AH-4 is always tuned when the PTT is pushed
after the frequency is changed (more than 1%). This
function removes the “push and hold [TUNER]” oper-
ation and activates first transmission on the new fre-
quency. This function is turned ON in initial set mode
(p. 46).
For mobile operation
For outdoor operation
Long wire
Optional AH-2b
antenna element
MIC
I
C-
718
PHONES
SQL
AF
SHIFT
RIT
LOCK
MODE FILTER
TS
PWR
TUNER
∫
∫
COMP
P.AMP
UP
NB
ATT
SET
CH
DN
ENT
F-INP
V/M
1
MW
4
A=B
2
M=CL
5
SCN
8
ANF
0
NR
.
A/B
3
VOX
9
7
SPL
M V
6
▲
AH-4
R
R
WARNING: HIGH VOLTAGE!
NEVER touch the antenna element while tuning or
transmitting.
Tuning is required for each frequency. Be sure to
re-tune the antenna before transmitting when you
change the frequency–even slightly.
Y
Y
[TUNER]
ï
Optional AH-4
AUTOMATIC ANTENNA TUNER
operation
Tuning indicator;
Blinks: Tuning now
Appears: Tune is completed
Disappears: Tune is not completed
AH-4 setting example: