50
5RECEIVE AND TRANSMIT
■Optional external tuner operation

•AH-4/AH-3 HF AUTOMATIC ANTENNA

TUNER

The AH-4/AH-3 matches the IC-756PROII to a long
wire antenna more than 3 m/10 ft long (3.5 MHz and
above) or more than 12 m/40 ft long (1.8 MHz and
above).
•See p. 19 for the transceiver and AH-4/AH-3 connection.
•See the AH-4/AH-3 instruction manual for AH-4/AH-3 in-
stallation and antenna connection details.
AH-4/AH-3 setting example:

RWARNING: HIGH VOLTAGE!

NEVER touch the antenna element while tuning
or transmitting.
NEVER operate the AH-4/AH-3 without an antenna
wire. The tuner and transceiver will be damaged.
NEVER operate the AH-4/AH-3 when it is not
grounded.
Transmitting before tuning may damage the trans-
ceiver. Note that the AH-4/AH-3 cannot tune when
using a 1⁄2λlong wire or multiple of the operating fre-
quency.
•When connecting the AH-4/AH-3, the antenna
connector assignments are [ANT2] for the internal
tuner and [ANT1] for the AH-4/AH-3. The antenna
indicator in the LCD displays “ANT1(EXT)” when
the AH-4/AH-3 is connected and selected.
•The AH-3 can be used for HF bands only. It can-
not be used for the 50 MHz band.

•AH-4/AH-3 operation

Tuning is required for each frequency. Be sureto
re-tune the antenna before transmitting when you
change the frequency—even slightly.
qSet the desired frequency in an HF or 50 MHz
band for use with the AH-4. Set the desired fre-
quency in an HF band for use with the AH-3.
•The AH-4/AH-3 will not operate on frequencies outside
of ham bands.
wPush [TUNER] for 1 sec.
•The [TUNER] light blinks while tuning.
eThe [TUNER] light lights constantly when tuning is
complete.
•When the connected wire cannot be tuned, the
[TUNER] light goes out and the AH-4/AH-3 is by-
passed. At that point the antenna wire connection rout
is to the transceiver directly, and not via the AH-4/AH-3
antenna tuner.
r
To bypass the AH-4/AH-3 manually , push [TUNER].
[TUNER] switch
For mobile operation
For outdoor operation
Long wire
Optional AH-2b
antenna element

•ANTENNA TUNER OF THE IC-PW1

When using an external antenna tuner such as the
IC-PW1’s tuner, tune with the external antenna tuner,
while the internal tuner is turned OFF. After tuning is
completed, turn the internal tuner ON. Otherwise,
both tuners tune simultaneously and correct tuning
may not be obtained.
See the instruction manual included with each an-
tenna tuner for their respective operations.