Icom IC-7600, Инструкция по эксплуатации, Страница: 130 / 196

■
Antenna tuner operation
The internal automatic antenna tuner automatically
matches the transceiver to the connected antenna.
After the tuner matches an antenna, the variable
capacitor 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 the Others set mode.
(p. 138)
D Tuner operation
➥
Push
[TUNER] to turn the internal antenna tuner
ON. The antenna is automatically tuned when the
antenna SWR is higher than 1.5:1.
• When the tuner is ON, the indicator on the switch lights
green.
• While tuning, the indicator on the switch blinks.
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.
➥
Hold down [TUNER] for 1 second, to start manual
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 seconds of tuning, the indicator on the switch goes out.
121
8
ANTENNA TUNER OPERATION
❍
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 the first time, it may tune the
antenna the second time.
❍
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 hold down
[TUNER] for
1 second to start manual tuning.
w
Set 3.80 MHz and hold down
[TUNER] for
1 second to start manual tuning.
NOTES:
•
NEVER transmit without an antenna properly
connected 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
tuning farther than 100 kHz from an antenna’s
programmed preset point, hold down
[TUNER] for
1 second to start manual tuning.
• The internal tuner may not be able to tune in
the
AM mode. In such cases, hold down [TUNER] for
1 second to manually tune.
TUNER