About Atu Operation - Yaesu FTDX9000MP Operation Manual

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D D D D D VICE VICE VICE VICE VICE
The ATU is connected both to the transmitter and
the receiver, and its natural RF selectivity has a ben-
eficial effect in rejecting out-of-band energy dur-
ing reception. Accordingly, we recommend that the
ATU be left "On" at all times.
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UICK UICK UICK UICK UICK
As shipped from the factory, only one ATU
alignment point is saved on each Amateur band.
This was memorized during the final alignment
and performance verification stages on the pro-
duction line.
The momentary flickering of the [ TUNE ]
switch's LED occurs whenever you cross over
into a new 10 kHz ATU memory window.
Figure 1 depicts a situation where normal tuning via the ATU has been successfully completed, and the tuning data has been
stored in the ATU memory. The antenna system as seen by the transmitter is shown.
In Figure 2, the operator has changed frequency, and the HI SWR LED has become illuminated. The operator presses and
holds in the [ TUNE ] switch for two seconds to begin impedance matching using the ATU.
If a high SWR conditions exists (above 3:1), corrective action must be taken in the antenna system to bring the impedance
closer to 50 Ohms. Besides the fact that the ATU will refuse to memorize settings on frequencies where the SWR exceeds
3:1, the high SWR may indicate a mechanical failure in the feed system, and such failures can lead to the generation of
spurious signals causing TVI, etc.
SWR = 2.0
Feed Point SWR
SWR = 1.5
SWR = 1.0
Frequency
SWR after ATU Tuning
Figure 1
SWR (Post-tuning) Less than 1.5:1
The tuning settings are committed to the ATU memory.
SWR (Post-tuning) Greater than 1.5:1
Tuning data will not be retained in memory. If you return to the same frequency, the tuning process must be repeated.
SWR (Post-tuning) Greater than 3:1
The HI SWR LED will light up, and tuning settings, if achieved, will not be memorized. Please investigate and
resolve the high SWR condition before attempting further operation using this antenna. The high SWR may indicate
a mechanical failure in the feed system, and such failures can lead to the generation of spurious signals causing TVI,
etc.
FT 9000MP O
DX PERATION
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SING SING SING THE
SING SING
P P P P P
OINT OINT OINT OINT OINT
A ATU O
BOUT
About ATU Memories
M
ANUAL
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THE THE THE UT UT UT UT UT OMA OMA OMA OMA TIC TIC TIC TIC TIC
THE OMA
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O O O O O TE TE TE TE TE
Although transmitter power is decreased to 200
Watts (maximum) during tuning, by all means
please check the operating frequency before begin-
ning the tuning process, to be sure you are not in-
terfering with others who may already be using the
frequency.
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ERMINOL ERMINOL ERMINOLOGY
ERMINOL ERMINOL
Antenna Tuner Memories
The microprocessor of the ATU makes a note of
the positions of the tuning capacitors and the se-
lected inductors, and stores the data for each 10
kHz window in which tuning has occurred. This
eliminates the need to re-tune every time you re-
turn to a frequency on which you already have com-
pleted the tuning process.
PERATION
Memorized ATU Setting
SWR = 3.0
SWR = 2.0
SWR = 1.0
Frequency ①
Figure 2
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NTENN NTENN A A A A A NTENN UNER UNER UNER
NTENN NTENN UNER UNER
OGY OGY OGY
OGY
Retuned Setting
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