12
The switch positions on the
DXE-EC-4
control the directivity of
the received signal in the
DXE-RFS-SYS-2P
.
As shown in the diagram to
the right, position one favors
the NE direction, position 2
favors the SE direction,
position 3 favors the SW
direction and position 4
favors the NW direction
when the array is positioned
as shown.
Control lines (usually BCD ) can normally use good quality CAT5e cable (4 twisted pairs of 24
AWG wire) for runs up to 1000 feet. Typical DX Engineering BCD control lines requirements are
+12 VDC at 25 milliamps. Depending on the number of control lines needed (usually 3 or 4) you
can double up the twisted pairs of CAT5e cable, or use control wire that is at least 22 AWG,
allowing runs up to 1500 feet. If you use a cable with more conductors, it is a good idea to tie the
unused conductors to ground. For longer runs of control cable, use a line loss calculator to ensure
you supply the proper control levels needed.
Approximate BCD Control Line Lengths.
Minimum Copper
Wire Gage (AWG)
Length
24
1,000 feet
22
1,500 feet
20
2,000 feet
Active antenna circuitry needs a good voltage supply to operate properly. When supplying power to
an active antenna, you want to have +12 VDC, 60 milliamps at each active (under load). CAT5e
cable is not recommended when making long runs to power an active antenna since the line loss in
CAT5e cable may not supply the proper operational voltages required for active antennas.
Depending on the required length of your power wire, you will want to use a line loss calculator
(voltage drop with various wire gages) to ensure your power supply (no13.6 well filtered
DC) will supply a minimum of +12 VDC, 60 milliamps at each active antenna (under load). A DX
Engineering 4 Square or 8 Circle will require approximately 250 milliamps (only 4 actives are
powered at any one time).
When calculating line length, take into consideration the total number of active antennas being
powered at any one time in your line length calculations.
