Optional External Tuner Operation - Icom IC-756PROIII Instruction Manual

■ Optional external tuner operation

• AH-4/AH-3 HF AUTOMATIC ANTENNA
TUNER
The AH-4 matches the IC-756PROIII to a long wire
antenna more than 7 m/23 ft long
The AH-3 matches the IC-756PROIII to a long wire
antenna more than 3 m/10 ft long
or more than 12 m/40 ft long
• See p. 18 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:
For mobile operation
For outdoor operation
Long wire
IC-756PROIII
R DANGER: 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
1
using a ⁄ λ long wire or multiple of the operating fre-
2
quency.
• 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.
.
(3.5 MHz and above)
(3.5 MHz and above)
.
(1.8 MHz and above)
Optional AH-2b
antenna element
ANTENNA TUNER OPERATION
• When connecting the AH-4/AH-3, the antenna
connector assignments are [ANT2] for the inter-
nal tuner and [ANT1] for the AH-4/AH-3. The an-
tenna 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 sure to
re-tune the antenna before transmitting when you
change the frequency—even slightly.
q Set 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.
w Push [TUNER] for 1 sec.
• The [TUNER] light blinks while tuning.
[TUNER]
e The [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 is to
the transceiver directly, and not via the AH-4/AH-3 an-
tenna tuner.
r To bypass the AH-4/AH-3 manually, push
[TUNER].
See the instruction manual included with each an-
tenna tuner for their respective operations.
10
10
90