Antenna Tuner Operation; D Tuner Operation; D Manual Tuning - Icom IC-7600 Instruction Manual

8

ANTENNA TUNER OPERATION

Antenna tuner operation
The internal automatic antenna tuner matches the
transceiver to the connected antenna automatically.
After the tuner matches an antenna, the variable capac-
itor settings are memorized as a preset point for each
frequency range (100 kHz steps). Therefore, when you
change the frequency range, the variable capacitors are
automatically preset to the memorized setting.
CAUTION: NEVER transmit with the tuner ON
when no antenna is connected. This will damage
the transceiver. Be careful of the antenna selection.
For your convenience
When you purchase a brand-new antenna, or you want
to change the antenna settings, you can erase the all
of the internal antenna tuner preset points with "Tuner
Preset Memory Clear" in others set mode. (p. 130)

D Tuner operation

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,
lights green.
• While tuning,

D Manual tuning

During SSB operation at low voice levels, the internal
tuner may not automatically tune correctly. In such
cases, manual tuning is helpful.
Push and hold [TUNER] for 1 sec., to start man-
ual tuning.
• A sidetone is emitted and the indicator on the
switch blinks red while tuning.
• If the tuner cannot reduce the SWR to less than
1.5:1 after 20 sec. of tuning, the indicator on the
switch goes out.
If the tuner cannot tune the antenna
Check the following and try again:
• the [ANT] connector selection.
• the antenna connection and feedline.
• the untuned antenna SWR. (Less than 3:1 for HF
bands; Less than 2.5:1 for 50 MHz band)
• the transmit power. (8 W for HF bands; 15 W 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 following:
• repeat manual tuning several times.
• adjust the antenna feedline length. (This is effective
for higher frequencies in some cases.)
Even if the manual tune does not tune the antenna and
the tuner turns OFF at the first time, it may tune the
antenna at the second time.
113
the indicator on the switch
the indicator on the switch blinks.
NOTES:
• NEVER transmit without an antenna properly con-
nected to antenna port in use.
• When 2 antennas are connected, select the
antenna to be used with [ANT] (MF1).
• If the SWR is higher than about 1.5:1 when tun-
ing farther than 100 kHz from an antenna's pro-
grammed preset point, push and hold [TUNER] for
1 sec. to start manual tuning.
• The internal tuner may not be able to tune in
AM mode. In such cases, push and hold [TUNER]
for 1 sec. to manually tune.
TUNER
Tuning a narrow bandwidth antenna
Some antennas, especially for the low bands, have
a narrow bandwidth. These antennas may not be
tuned beyond the edge of their operating bandwidth,
therefore, tune such an antenna as follows:
[Example]: Suppose you have an antenna which
has an SWR of 1.5:1 at 3.55 MHz and
an SWR of 3:1 at 3.8 MHz.
q Set 3.55 MHz and push and hold [TUNER] for
1 sec. to start manual tuning.
w Set 3.80 MHz and push and hold [TUNER] for
1 sec. to start manual tuning.