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If the array is used on 160m or below, the Active Antenna internal jumper should be set as shown in
the Installation Section of this manual. If the array still lacks sensitivity on the lower bands, then a
preamplifier with high dynamic range should be used to compensate for the low signal level. Using
a preamplifier when sufficient signal is already present may result in amplification of the noise
along with the signal.
It is always best to use the least gain possible
. Depending on conditions, a
preamplifier can cause receiver overload; this may require an attenuator or bypassing the
preamplifier.
The
DXE-RPA-1
HF Preamplifier has better dynamic range than most receivers and can be used to
compensate for the decrease in array signal output. The
DXE-RPA-1
preamplifier is automatically
bypassed when power is removed.
Front-to-Rear (Null) Optimizing
The
DXE-RFS-3
is factory adjusted to the correct
settings for most coaxial cables. In rare cases, the
null depth may need to be adjusted to compensate
for inaccurate delay line lengths. To adjust the null
depth, tune to a strong steady signal off the back
of the antenna’s selected direction and adjust R4
and R8 for the deepest null (weakest signal off the
back). Use
Figure 5
to locate R4 and R8 near the
center of the circuit board.
Operation
When using the
DXE-RFS-3
, positions 1 though 4
on the
EC-4
BCD Control Box will phase the
appropriate active vertical elements to give you
excellent receiving capabilities.
The front to back signal to noise ratio of the active
vertical elements in the four phase array allow you
to not only enhance the desired received signal,
but also to decrease an unwanted receive signal by
selecting a position that will drastically reduce or
eliminate it.
Normal Receive Four Square Operation
When the Receive Four Square system is functioning properly, low or medium power daytime AM
Broadcast ground wave signals should be alternately attenuated or improved with directional
switching. However, strong sky wave signals arriving at high angles of propagation will show very
little signal level change as different directions are selected on the Receive Four Square.
