ICOM IC-703 Benutzerhandbuch

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The internal automatic antenna tuner matches the
transceiver to the connected antenna automatically.
Once the tuner matches an antenna, the latching relays
combination are memorized as a preset point for each
frequency range (100 kHz steps). Therefore, when you
change the frequency range, the latching relays are au-
tomatically preset to the memorized combination.

NEVER transmit with the tuner ON

when no antenna is connected. This will damage
the transceiver. Be careful of the antenna selection.

Push [TUNER] to turn the internal antenna tuner
ON. The antenna is tuned automatically when the
antenna SWR is higher than 1.5:1.

• When the tuner is ON, the ‘TUNER’ indicator lights red.

Push [TUNER] for 1 sec., to start manual tuning.

• A side tone is emitted and ‘TUNER’ indicator blinks

while tuning.

• If the tuner cannot reduce the SWR to less than 1.5:1

after 20 sec. of tuning, the ‘TUNER’ indicator goes out.

The tuner is always tuned when the PTT is pushed
after the frequency is changed (more than 1% from
last-tuned frequency). This function removes the
“push and hold [TUNER]” operation and activates for
the first transmission on a new frequency.

This function can be turned ON in initial set mode 
(p. 81).

qMake sure the transceiver power is OFF.

wWhile pushing [Y] and [Z], push [POWER] to turn

power ON.

• “

CLEAR ? OK” appears as shown below.

eRotate main dial to select tuner reset.

rThen Push [F-3] for 1 sec to start tuner resetting.

• The memorized tuner settings are reset.

[TUNER]

Lights to indicate internal tuner is activated.

CLEAR ?  OK

[POWER]

[

Y]

[

Z]

DIf the tuner cannot tune the antenna

Check the following and try again:

• the antenna connection and feedline.
• the unaltered antenna SWR. 

(Less than 3:1 for HF bands;

Less than 2.5:1 for 50 MHz band)

• the power source voltage/capacity.

If the tuner cannot reduce the SWR to less than
1.5:1 after checking the above, perform the follow-
ing:

• repeat manual tuning several times.
• tune with a 50 

Ω dummy load and re-tune the antenna.

• turn power OFF and ON.
• adjust the antenna cable length.
(This is effective for higher frequencies in some cases.)
• Some antennas, especially for low bands, have a nar-

row bandwidth. These antennas may not be tuned at
the edge of their bandwidth, therefore, tune such an
antenna as follows:

• The internal antenna tuner can tune the HF to 50 MHz

bands.

• NEVER transmit without an antenna properly connected

to antenna port in use.

• If the SWR is higher than about 1.5:1 when tuning

above 100 kHz on an antenna’s preset point, push
[TUNER] for 1 sec. to start manual tuning.

• When strong impact is applied, the internal tuner may

not work properly caused by the latching relay is off po-
sition.

In this case, push [POWER] momentarily

to reset

the all latching relays while transceiver power is ON.

DInternal antenna tuner

DTuner operation

■Antenna tuner operation