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

Optional external tuner operation

• AH-4/AH-3 HF AUTOMATIC ANTENNA
TUNER
The AH-4/AH-3 matches the IC-756PRO 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. 20 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
R WARNING: 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 ⁄ long wire or multiple of the operating fre-
2
quency.
• ANTENNA TUNER OF THE IC-PW1, IC-4KL or IC-2KL/IC-AT500
When using an external antenna tuner such as the
IC-PW1's tuner, IC-4KL's tuner or IC-AT500 with a lin-
ear amplifier, 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.
• 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 sure to
Optional AH-2b
re-tune the antenna before transmitting when you
antenna element
change the frequency—even slightly.
q Set the desired frequency in an HF or 50 MHz
band for using with the AH-4. Set the desired fre-
quency in an HF band for using with the AH-3.
• The AH-4/AH-3 will not operate on frequencies outside
of ham bands.
w Push [TUNER] for 2 sec.
• The [TUNER] light blinks while tuning.
e The [TUNER] light lights constantly when tuning is
complete.
• When the connected wire cannot be tuned, the
[TUNER] light goes out, the AH-4/AH-3 is bypassed
and the antenna wire is connected to the antenna con-
nector on the transceiver directly.
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.
RECEIVE AND TRANSMIT
[TUNER] switch
5
49