18
4
OPERATION
The AT-120, AT-130 or AH-4 matches the IC-78 to a
long wire antenna more than 7 m (23 ft) long (3.5 MHz
and above).
• See p. 11 for connection.
• See the connected antenna tuner’s instruction man-
ual for installation and antenna connection details.
• Setting example:
NEVER operate the AT-120, AT-130 or AH-4 without
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
1
⁄2 λ long wire or multiple of the op-
erating frequency.
TUNER OPERATION
•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 [UPY] or [Z DN] 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.
e “”lights constantly when tuning is completed.
(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.
r To bypass the antenna tuner manually, push
[TUNER]. (AH-4 only; starts tuning again when AT-
120 or AT-130 is connected)
