18
VL-2000 Operating Manual
Operation
A
uTomATic
A
nTennA
T
uner
o
perATion
The Automatic Antenna Tuner built into the
VL-2000
is crafted to ensure a 50-Ohm load for the final amplifier stage of
the linear amplifier. We recommend the Automatic Antenna Tuner be used whenever you operate the
VL-2000
.
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dvice
:
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The
VL-2000
Automatic Antenna Tuner, being located inside the station, only adjusts the impedance presented to the
transmitter at the station end of your coaxial cable feedline. It does not “tune” the SWR at the antenna feedpoint itself.
When designing and building your antenna system, we recommend that every effort be made to ensure a low SWR at
the antenna feedpoint.
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The
VL-2000
Automatic Antenna Tuner includes 470 memories for tuning data. These memory allocation is described
in the bottom chart.
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The
VL-2000
Automatic Antenna Tuner is designed to match impedances within the range of 16.5 Ohms to 150 Ohms,
corresponding to an SWR of 3:1 or less on the HF amateur bands (6 meter amateur band: 25 Ohms to 100 Ohms, corre-
sponding 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 Automatic Antenna
Tuner.
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The
VL-2000
Automatic Antenna Tuner is located between the final amplifier and the rear-panel antenna jack; recep-
tion is not affected by the Automatic Antenna Tuner.
1. Confirm the operating band of the
VL-2000
is same
as the exciter.
2. Press the
TUNE
button briefly to place the Automatic
Antenna Tuner in the transmit line. The
TUNE
LED
will glow red.
3. Press and hold the
TUNE
button for 1/2 second to
begin automatic tuning. The transmitter will be en-
gaged, and the red
TUNE
LED will blink while tun-
ing is in progress. When the optimum tuning point
has been reached, the transceiver (and
VL-2000
) will
return to receive, and the
TUNE
LED will glow red
steadily (instead of blinking).
4. To disconnect the Automatic Antenna Tuner
from the transmit line, press the
TUNE
button briefly.
The
TUNE
LED will turn off, confirming that the
Automatic Antenna Tuner has been turned off. In the
“off” mode, the transceiver will be directly connected
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.
m
emory
c
hAnnel
A
llocATionS
b
And
m
emory
c
hAnnel
S
Tep
1.8 MHz
20 channels for each ANT Jack (x5)
10 kHz
3.5 MHz
25 channels for each ANT Jack (x5)
20 kHz
7 MHz
6 channels for each ANT Jack (x5)
50 kHz
10 MHz
1 channel for each ANT Jack (x5)
---
14 MHz
5 channels for each ANT Jack (x5)
100 kHz
18 MHz
1 channel for each ANT Jack (x5)
---
21 MHz
6 channels for each ANT Jack (x5)
100 kHz
24 MHz
1 channel for each ANT Jack (x5)
---
28 MHz
9 channels for each ANT Jack (x5)
200 kHz
50 MHz
20 channels for each ANT Jack (x5)
200 kHz
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dvice
The
VL-2000
Automatic Antenna Tuner makes a
note of the positions of the tuning capacitors and
the selected inductors when the tuning result is
better than SWR 1.5:1. This eliminates the need
to re-tune every time you return to a frequency on
which you already have completed the tuning pro-
cess.
n
oTe
The
VL-2000
Automatic Antenna Tuner does not
tuning in the following situations:
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The exciter (transceiver) is not transmitted.
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No carrier.
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Low injection level.
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Antenna SWR is more than 3.0: 1.
(short-circuit or open-circuit)
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Tuning result is more than 3.0: 1.
r
eSeTTinG
The
A
nTennA
T
uninG
d
ATA
The
VL-2000
can be reset so as to clear the an-
tenna tuner tuning data; this will be reset to the
factory default.
To reset the Antenna Tuning Data, press and hold
in the
TUNE
button while you turn the
VL-2000
on.
FCC ID: K6620321X70
Vertex Standard Co., Ltd.
