AOR LA390 User manual

HI-Q active loop antenna
LA390
Instruction Manual
AOR,LTD.
Authority on Radio Communications
®

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The LA390 is a compact active (30.5cm diameter) loop antenna specifically designed to
provide good reception when away from the main monitoring location or when large
external antennas are not practical. Compact, b t achieving high performance, feat ring
an internal high-gain amplifier.
LA390 vs. LA380
With similar performances, the LA390 offers in addition preselection for L.W and M.W bands, b t not for the
specific 40kHz and 60kHz time signals. Preselection sharpness has also been improved.
Directivit
A rotating loop antenna is very directional. Depending on the loop’s orientation, yo can peak an incoming
signal depending on its direction, or decrease an interfering signal.
For example the n lling feat re will allow yo to remove a station on a freq ency and pick p another
(transmitting from a different direction) on the same freq ency. Of co rse the directional characteristics
when listening to distant sky-wave signals will not be as prono nced as local gro nd-wave propagation.
Thanks to its directivity, it is also ideal for minimizing the effects of nwanted interfering local terrestrial
signals and noise.
The loop element feat res a 5 position band switch and a High-Q poly-variable capacitor (only active for
switch positions 1 to 4) to t ne and peak the wanted freq ency, while achieving maxim m rejection of
nwanted o t of band signals. This provides val able additional selectivity for yo r receiver’s front-end
stages.
Using the LA390 active loop antenna
1) Connect the power s pply to the rear panel
DC inp t socket, the LA390 req ires 12V DC
at 80mA (9-15V DC). A 9V reg lator is b ilt
into the LA390 control nit.
To minimize noise, keep the power s pply as
far away from the LA390 as practical. To
minimize electrical interference from the
power s pply, for the reception of L.W and
M.W bands, yo may wish to consider se of
a (non s pplied) low noise reg lated power
s pply.

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2) Connect the s pplied BNC-BNC coaxial lead between the LA390 and yo r receiver’s antenna inp t. If
yo r receiver is fitted with a connector other than BNC, an appropriate adaptor m st be sed.
3) Insert the receiving loop element into the top panel BNC socket of the LA390 cabinet.
4) P sh the red front panel power switch, the green LED will ill minate to confirm that power is connected to
the control nit.
5) Switch on the receiver and t ne to the desired freq ency. Select the correct freq ency range with the
band switch on the loop element. There are 5 positions to choose from:
Switch position Frequencies Comments
1 150-800kHz Longwave (148.5-283.5kHz)
2 700kHz-3MHz Medi mwave (520kHz-1710kHz)
3 3-10MHz Shortwave bands 100 to 30 Meters
4 10-30MHz Shortwave bands 30 to 7.5 Meters
5 Others Between 10kHz and 500MHz, antenna acts as an amplified whip.
6) Rotate the t ning dial on the loop element (clockwise and anticlockwise) ntil the receiver signal strength
meter (S-meter) deflects to maxim m and the incoming signal so nds clearest. If yo r receiver does not
have an S-meter, simply adj st for maxim m received signal. Rotate the loop element ntil the signal is
strongest and any interfering signal is n lled.
(Position 5 is non-tunable, as the loop is wired to act as an amplified whip)
It is advisable to locate the LA390 close to a window in
order to achieve the best possible reception.
In case yo r listening station is too far way from a
window, yo have the possibility to se a (non-s pplied)
BNC-BNC coaxial patch lead between the control box
and the loop. A gender change is req ired at one end of
the cable, please se a BNC-BNC in-line socket.
The lead sho ldn’t be longer than 5m.

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LA390 Specifications:
Freq ency range 10kHz-500MHz, 5 bands selectable
Impedance 50 Ohm
Typical gain 150kHz: 23dB
25MHz: 20dB
50MHz: 20dB
30MHz: 20dB
250MHz: 17dB
500MHz: 10dB
Connector BNC
Loop element size 305(W)x365(H)x60(D)mm
Control box size 120(W)x55(H)x85(D)mm
Weight Loop: 250g, control box: 230g
Cable 1m RG58A/U (BNC pl gs)
Power External DC 12V (9-15V), approx. 80mA.
DC connector 1.3mm centre positive
LA390 Control box with loop
AC power s pply
S pplied acc.
BNC-BNC Coaxial patch lead (1m)
Specifications s bject to change witho t notice or obligation.
Precautions
The LA390 is NOT intended for transmit purposes.
Keep it away from excessive h midity and rain. LA390 is NOT waterproof.
We are not responsible for any damages to the antenna or yo r radio eq ipment d e to improper se.
E&OE AOR LTD, 2008
Copyright © 2008 All rights reserved
AOR, LTD.
2-6-4, Mis ji, Taito-K
Tokyo, 111-0055, Japan
http://www.aorja.com
[e-mail]