Optional External Tuner Operation - Icom ic-718 Instruction Manual

5
RECEIVE AND TRANSMIT
ï Optional external tuner operation
R DANGER! HIGH VOLTAGE!
NEVER touch the antenna element while tuning
or transmitting. Always place it in a secure place.
NEVER operate the AH-4 or AH-740 without an an-
tenna connected. The tuner and transceiver will be
damaged.
NEVER operate the AH-4 or AH-740 if it is not
grounded.
Transmitting before tuning may damage the transceiver.
Note that the AH-4 cannot tune when using a 1⁄2  long
wire or multiple of the operating frequency.
AH-4
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 page 14 for connection details.
• See the AH-4 instruction manual for AH-4 installa-
tion and connection details.
AH-740
The optional AH-740 covers 2.5 to 30 MHz range with
a supplied whip antenna element. Or when using with
the optional NVIS kit, it covers 2.2 to 30 MHz range.
• See page 14 for connection details.
• See the AH-740 instruction manual for the installa-
tion and connection details.
30
TUNER OPERATION
Tuning is required for each frequency. BE SURE
to retune the antenna before transmitting when you
change the frequency, even slightly.
• Tuner type setting (p. 46)
q Hold down [PWR] for 1 second to turn power OFF.
w While pushing and holding [SET], push [PWR] to
turn ON the power.
e Push [UP Y] or [Z DN] one or more times to se-
lect [TUNER].
r Rotate the main dial to select "4."
• AH-4
AUTOMATIC ANTENNA TUNER
• Also select "4" when using the optional AH-740.
t Hold down [PWR] for 1 second to turn power OFF.
y Push [PWR] to turn ON the power.
• MANUAL TUNING
q Set the desired frequency in an HF band.
• The IC-718 will not transmit outside of the ham bands.
w Hold down [TUNER] for 1 second.
• " " blinks and "CW" appears while tuning.
e
lights constantly when tuning is complete.
" "
• When the connected wire cannot be tuned, "
out, the AH-4 or AH-740 is bypassed and the antenna
wire is directly connected to the antenna connector on
the transceiver.
r To manually bypass the AH-4 or AH-740, push
[TUNER] to turn it OFF.
Tuning indicator;
Blinks: Tuning now
Appears: Tune is completed
Disappears: Tune cannot be completed
CONVENIENT
• PTT tune function
The AH-4 or AH-740 is always tuned when the PTT
is pushed after the frequency is changed more than
1%. This function removes the "hold down [TUNER]"
operation and activates fi rst transmission on the new
frequency. This function is turned ON in initial set
mode (p. 46).
is selected.
Y
[TUNER]
" goes