Introduction - AOR LA400 Instruction Manual

1. Introduction

Thank you for purchasing the LA400 Magnetic loop antenna.
To get the best possible results from your LA400, we recommend that you read this manual
and familiarize yourself with the antenna.
Since the invention of this revolutionary concept by KOLSTER in 1915, loop antennas,
especially of the active type, have also been widely used by the military in the 70's, before
becoming very popular among hobby listeners.
In recent years, the increase in man-made local noise (typical city noise) poses a problem
for the reception of distant signals in the long wave, medium wave and shortwave bands.
LA400 is our latest product based on the technology we developed since the original LA320
loop antenna. In addition to its exceptional directivity in order to minimize the effects of local
noise, the revolutionary LA400 offers, with its REMOTE TUNING SYSTEM, the perfect
solution to keep the antenna away from noise sources by setting it up in quiet areas!
While the control (tuning) box stays at hand's reach, the loop element can be set away by
using simple LAN and BNC coaxial cables.
10kHz to 500MHz, 5 position band switch to peak only on the wanted signal. Small size
30.5cm diameter loop with exceptional 20dB gain
Remote tuning – Unlike previous amplified indoor loop antennas, the band switching and
fine tuning controls are not tied anymore to the loop element. With these controls now on
the control box and by using the LA400-RCK optional extension cables, it is now possible
to tune the antenna while the loop element is setup at the most reception friendly location
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possible (window, covered balcony, etc...). Compatible with 3 party cables. Maximum
length: 20m.
A relay system is used for band switching, providing excellent isolation characteristics.
The relay is efficiently placed inside the loop element, while you can operate it through the
control box via the control cable.
Electronic tuning from 150kHz 〜 30MHz allows very sharp tuning to the desired
frequency. Shift the aligning point slightly to attenuate unwanted signals while amplifying
the wanted signal.
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