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3) If the voltages are not normal, less than +10 to +18 Vdc, with the control line connected, then
disconnect the control line and retest the Control Console. If voltages that were not correct, are
now okay, that indicates a short in the control line or a problem in or beyond the
RFS-3
Receive Four Square relay unit.
4) If the
EC-4
has only a couple LEDs lit with the control cable disconnected, then it may have
sustained lightning pulse damage and will need to be repaired or replaced. A new
DXE-EC-4
is available from DX Engineering.
Continue troubleshooting the array control
with a good
EC-4
or by using a well filtered 1A
fused power source.
5) Determine if the control line is intact by resistance or voltage testing each conductor for shorts
with the far end of the control cable disconnected from the
RFS-3
unit.
6) With a good
EC-4
or other power source connected, measure A, B and C control conductor
voltages at the
RFS
relay unit with the control cable connected, and again at the end of the
control cable that is disconnected from the
RFS
relay unit. If measured voltages are not
b10 to +18 Vdc on the selected line, a resistive, short or open circuit problem exists in
the control line or in the
RFS
relay unit or antenna feedlines. Normal voltages on the connected
control line will cause relays to switch inside the
RFS
unit. If switching voltages are correct,
lack of system directivity or gaps in reception may be due to antenna, feedline or delay line
issues.
7) Test the Active Antennas by feeding a voltage on the tested control line A and/or B
conductor(s) to select one direction of
RFS
unit operation. Simultaneously feed normal
operating voltage on the tested conductor that powers the Active Verticals for reception. If a
low value fuse blows, then a short circuit may be isolated by disconnecting antennas and
reconnecting them one at a time.
If no fuses have blown and connected voltages stay near the n12 Vdc levels, then:
8) Test for active operating voltage at the end of each antenna feedline. If all are good, proceed. If
not, repair feedlines and/or connectors. If voltage is present on the power line to the
RFS
relay
unit, but is not measured at the end of good feedlines, inspect inside
RFS-3
relay unit to
determine if there is an obvious reason that Active Vertical Antenna power is not making it out
the antenna ports. A bad connection outside of the
RFS
relay unit is usually the problem, and
rarely has a component failure inside the
RFS
relay unit been discovered. If the system
previously functioned properly, then the internal jumpers would have been previously set in
their proper positions for your system configuration. If you are troubleshooting a new system
or using a replacement unit, check that the internal jumpers in the
RFS-3
unit are set correctly
for your system control and voltage configuration.
Proper Receive Four Square phasing
requires that each Active Vertical Antenna, and its
respective equal length feedline, actually provides the same signal level to the RFS unit.
Use a steady, non-fading ground wave signal from a low or medium power daytime AM
Broadcast station that is over 10 miles away, on a frequency high in the band, or another
constant signal source on 160 or 80 meters, well away from the array, to test that each Active
Vertical receives the same signal level. Do not use sky wave or night signals for these signal
level tests.
