Page 144 FT-
991
The optional
Automatic Antenna Tuner provides automatic tuning of a coaxial line to present nominal 50-ohm
impedance to the
’s ANT jack.
Before operation can begin, the
microprocessor must be setup to accommodate the
automatic tuner.
This is done using the Menu Mode:
(
)
1. Press the
button to enter the Menu
mode.
2. Rotate the
knob to select the Menu Item “
141
TUNER SELECT
”.
3. Touch
[
]
on the LCD, then rotate the
knob to select “
EXTERNAL
”.
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'5'%6.
+
/:6:/# 219'4
0
/+
6'40#.
4. Touch
[
]
on the LCD to save the new setting.
670'4'5'%6. ':6'40#.
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'5'%6.
/:6:/# 219'4
/+
5. Press the
button or touch
[
]
on the LCD to exit to normal operation.
1. Press the
button briefly to activate the
Automatic Antenna Tuner.
2. The “
” icon will appear in the TFT display.
3. Press and hold the
button for one second
to begin automatic tuning. The transmitter will be
engaged, and the “
” icon will blink while
tuning is in progress.
4. Tuning will stop automatically when a low SWR is
achieved. You may Press the
button while
tuning is in progress, to cancel the automatic tuning.
5. To disable the Automatic Antenna Tuner, press the
button briey again.
MULTI Knob
MENU
(
SETUP
)
Button TUNE Button
Be sure to connect a good earth ground to the GND
terminal of the
.
The carrier signal transmits continuously while
tuning is in progress. Please monitor the operating
frequency before beginning the tuning process. Be
sure you are not interfering with others who may
already be using the frequency.
It is normal to hear the sound of the relays while
tuning is in progress.
If the impedance cannot be matched by the
better than 2:1, and the “
” icon blinks, the
microprocessor will not retain the tuning data for that
frequency, as the
presumes that you will want
to adjust or repair your antenna system to correct the
high SWR condition.