MFJ-1780
Box Fan
Loop Antenna Instruction Manual
5
either too far away or is not a good enough RF
reflector to cancel the horizontal radiation
component of the vertical loop.
HORIZONTAL POLARIZATION:
Horizontal mounting of the loop antenna results in
an omni-direction, horizontally polarized pattern
that has a null straight up in the air and straight
below the center of the antenna. This means that
any ground reflection will tend to cancel the
radiation along the horizon, and also at low wave
angles unless the loop is mounted some distance
above ground.
Note:
Do not expect the best results if you mount
this loop antenna horizontally less than 15
feet above ground.
Since ground wave signals only propagate well
along the earth when they are vertically
polarized, a horizontally polarized loop
may not respond to some local noise
sources. Like all other antennas, a small loop is generally a quieter receiving antenna when horizontally
polarized. This also means that a horizontally polarized loop is not a good choice for local ground
wave communications. It is an excellent choice for medium to long distance sky wave
communications, however.
OUTDOOR USE
Note :
The MFJ
Box Fan
Loop
can
be used outdoor only in good
weather conditions
( not in windy or
stormy weather).
WARNING
When operating outdoors it is IMPORTANT to:
Figure 3
Figure 4
