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.
