Using The Automatic Antenna Tuner; Atu Operation - Yaesu FTdx5000 Series Operating Manual

U
SING THE
The Automatic Antenna Tuner ("ATU") built into each FT
stage of the transmitter. We recommend the ATU be used whenever you operate the FT
A :
The ATU of the FT 5000, being located inside the station, only adjusts the impedance presented to the transmitter at
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the station end of your coaxial cable feedline. It does not "tune" the SWR at the antenna feedpoint itself. When design-
ing and building your antenna system, we recommend that every effort be made to ensure a low SWR at the antenna
feedpoint.
The ATU of the FT 5000 includes 100 memories for tuning data. Eleven of these memories are allocated, one per
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Amateur band, so that each band has at least one setting preset for use on that band. The remaining 89 memories are
reserved for the 89 most-recent tuning points, allowing quick frequency change without the need to retune the ATU.
The ATU in the FT 5000 is designed to match impedances within the range of 16.5 Ohms to 150 Ohms, correspond-
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ing to an SWR of 3:1 or less on the HF amateur bands (6 meter amateur band: 25 Ohms to 100 Ohms, corresponding to
an SWR of 2:1 or less). Accordingly, simple non-resonant whip antennas, along with random-length wires and the
"G5RV" antenna (on most bands) may not be within the impedance matching range of the ATU.
1. Rotate the [ RF PWR ] knob fully clockwise (to the
right).
2. Use the Main Tuning Dial knob to set the radio to the
desired operating frequency within the Amateur band.
3. Press the [ TUNE ] button briefly to place the ATU in
the transmit line (no adjustment/tuning will occur yet).
The " " icon will appear in the display.
Q P :
The brief press of the [ TUNE ] button will turn the tuner
on, and the microprocessor will automatically select
the tuning point closest to the current operating fre-
quency.
4. Press and hold in the [ TUNE ] button for two seconds
to begin automatic tuning. The transmitter will be en-
gaged, and the " " icon will blink while tuning is
in progress. When the optimum tuning point has been
reached, the radio will return to receive, and the
" " icon will again glow steadily (instead of
blinking).
5. While tuning around the band using the Main Tuning
Dial knob, you will observe that the "
blinks momentarily every 10 kHz. This momentary
blinking indicates that a new tuning window has been
entered. If you want to save tuning data associated with
each 10 kHz window, repeat step 4 (above) for each of
the windows. On bands like 1.8 MHz where the im-
pedance may change rapidly, the storage of a number
of tuning points is recommended.
6. To disconnect the ATU from the transmit line, press
the [ TUNE ] button briefly. The "
off, confirming that the ATU has been turned off. In
the "Off" mode, the transceiver will be directly con-
nected to the coaxial cable connected to your antenna,
and it will operate based on whatever impedance is
present at the station end of the coax.
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A
UTOMATIC
ATU O
" icon
" icon will turn
A
NTENNA
5000 is crafted to ensure a 50-Ohm load for the final amplifier
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PERATION
[ TUNE ] Button
[ RF PWR ] Knob
A :
The ATU circuit is located between the final amplifier and
the rear-panel antenna jack; reception is not affected by
the ATU.
Q P :
As shipped from the factory, only one ATU alignment
point is saved on each Amateur band. This was memo-
rized during the final alignment and performance veri-
fication stages on the production line.
The momentary flickering of the "
whenever you cross over into a new 10 kHz ATU
memory window.
N :
Please check the operating frequency before beginning the
tuning process, to be sure you are not interfering with oth-
ers who may already be using the frequency.
T :
Antenna Tuner Memories: The microprocessor of the ATU
makes a note of the positions of the tuning capacitors and
the selected 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 return to a frequency on
which you already have completed the tuning process.
FT
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T
UNER
5000.
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" icon occurs
5000 O M