Icom IC-78 Instruction Manual page 20

4
OPERATION
ï Optional AT-120/AT-130/AH-4 operation
The AT-120, AT-130 or AH-4 matches the IC-78 to a
long wire antenna more than 7 m
and above).
• See p. 11 for connection.
• See the connected antenna tuner's instruction manual
for installation and antenna connection details.
• Setting example:
For mobile operation
For outdoor operation
AT-120
AT-130
AH-4
R WARNING: HIGH VOLTAGE!
NEVER touch the antenna element while tuning or
transmitting.
NEVER operate the AT-120, AT-130 or AH-4 with-
out an antenna wire. The tuner and transceiver will
be damaged.
NEVER operate the AT-120, AT-130 or AH-4 when it
is ungrounded.
Transmitting before tuning may damage the trans-
ceiver. Note that the AT-120, AT-130 or AH-4 cannot
tune when using a
operating frequency.
18
long (3.5 MHz
(23 ft)
Optional AH-2b
antenna element
Long wire
λ long wire or multiple of the
⁄
1
2
TUNER OPERATION
Tuning is required for each frequency. Be sure to
re-tune the antenna before transmitting when you
change the frequency— even slightly.
• Tuner type setting (p. 32)
q Push [PWR] for 1 sec. to turn power OFF.
w Enter initial set mode.
• Turn power ON while pushing and holding [SET].
e Push [Z DN] or [UP Y] to select [TUNER].
r Selects connected antenna tuner type by rotating
the channel selector.
• no : no antenna tuner is selected.
• 4 : AH-4 is selected.
• 12 : AT-120 is selected.
• 13 : AT-130 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 channel.
w Push [TUNER] to start tuning.
• " " blinks and "CW" appears while tuning.
lights constantly when tuning is completed.
e
" "
( except when AT-120 is connected; the indicator
goes out)
• When the connected wire cannot be tuned, the "
goes out, the antenna tuner is bypassed and the an-
tenna wire is connected to the antenna connector on
the transceiver directly.
Tuning indicator;
Blinks: While tuning
Appears: Tune is completed
Disappears: Tune is not completed
(When AT-120 is connected, the
indicator disappears even when
tuned completely.)
r To bypass the antenna tuner manually, push
[TUNER]. (AH-4 only; starts tuning again when
AT-120 or AT-130 is connected)
[TUNER] switch
"