24
DXE-RFS-2 and Active Element Power
The
DXE-RFS-2
phasing unit uses and distributes the voltage to power the active antenna elements.
For all four active elements, a n12-15 Vdc at 200 mA current is required. The default
configuration uses Terminal C on the 5-position plug for power.
The
DXE-CC-8A
uses positions 5 through 8 to power and control the
DXE-RFS-2
. The default
direction is selected when LED #5 is illuminated. This setting provides operating voltage on
Terminal C of the
DXE-CC-8A
, which is connected to Terminal C on the
DXE-RFS-2
. (The active
elements do not work without power.) See
Table 4
; note that “C” has voltage in all four positions.
If the
TVSU-1A
Sequencer is used, it will provide keyed power for the
DXE-RFS-2
for the active
verticals.
Alternatively, the coax can be used to power the elements. This requires the default jumper settings
to be changed. See the next section for alternate jumper settings. You must provide a way to couple
this voltage on the feedline.
Directional Control
The default configuration of the
DXE-RFS-2
phasing unit uses a 2-bit, +12 Vdc BCD interface
scheme to switch directions through a user-supplied 4 conductor cable connected to the
DXE-CC-8
.
The default direction without applied control voltage is in the direction of Element 1. Element 3 is
the default rear or null direction.
Table 4
shows the array direction, the truth table for the BCD interface (A&B) and the status of the
LED indicators on the
DXE-CC-8A
for each direction. (Terminal C is used to power the
DXE-
RFS-2
so it is always on.)
Forward Direction
Rear Direction
A
B
C
CC-8A LED Illuminated
Element 1 (Default)
Element 3 (Default)
0
0
1
# 5
Element 2
Element 4
1 0 1
#6
Element 3
Element 1
0
1
1
#7
Element 4
Element 2
1 1 1
#8
Table 4 - BCD Directional Control Matrix, “1” 12 Vdc (Default)
Alternatively, directional control using differential voltages can be done through the coax feedline
or Terminal C on the
DXE-FS-2
. This requires the default jumper settings to be changed. See the
next section for jumper settings. Directional control through Terminal C requires only one
conductor plus a ground return path. That return path can be the coax shield or an additional
conductor specifically dedicated to that purpose. Terminal C cannot be used for powering the
DXE-
RFS-2
if it is being used for directional control.
