TX RX Systems Inc. Manual 7-9487-3 05/05/11 Page 33
amplifier and automatically switches to the identical
secondary quad-amplifier if conditions indicate a
primary malfunction.
A loss of communications (along the main trans-
mission line) between the microprocessors in the
base unit and tower box will cause the front panel
A and B indicator LED’s to flash RED. The ALARM
Form-C contacts located at the back of the unit will
also change state.
THE TEST MODE
The TEST sub-menu allows the field engineer to
choose the active tower top amplifier as well as
control the input of each of the tower top amplifiers
via software. The base amplifier is always active.
When you use functions in the TEST sub-menu
you are operating the system in the test mode. Be
aware that some of these tests will interrupt the RF
signal path through the tower top box and on-air
signals will not be passed to the station receivers.
We recommend that when you are in the test mode
and you complete your testing use the CANCEL
button to exit back to normal mode and the default
display. If you exit the test mode without using the
CANCEL button and leave one of the amplifiers in
other than its normal operating condition the mes-
sage “NonFunctional” will appear in the LNA X
ACTIVE sub-menu. As a safety feature the system
will switch out of the test mode and back into the
normal mode of operation after about 9 minutes of
inactivity. Each of the three functions available
through the TEST sub-menu is described below.
Set LNA X Active
Allows the selection of the active amplifier via soft-
ware interface.
1) From the TEST sub-menu display use the
ARROW button to scroll over to the SET LNA
“A (or) B” ACTIVE menu choice, depending on
which amplifier you want to choose as the
active amp, and press the ENTER button.
2) If you choose to make the already active ampli-
fier active again, the system will return you to
the TEST sub-menu. If you choose to make the
non-active amplifier active, then the “Test TTA
Offline” message will appear. The RF signal
path through the tower top box will be inter-
rupted and on-air signals will not be passed to
the station receivers.
3) Pressing the CANCEL button returns you to the
default display. Whichever amplifier you had
selected to be active in the TEST sub-menu will
now be the active amplifier back in the normal
mode and on-air signals will again pass through
to the station receivers.
If left unattended, after about 9
minutes the system will switch out
of the test mode and back into the
normal mode of operation. The
amplifier selected while in the test
mode will now become the active
amp and on-air signals will again
pass through to the station receiv-
ers.
Terminate LNA X
Allows you to connect the input of either of the
tower top amplifiers to its internal 50 ohm load.
1) From the TEST sub-menu display use the
ARROW button to scroll over to the TERMI-
NATE LNA “A (or) B” menu choice and press
the ENTER button.
2) If you choose to terminate the input of the non-
active amplifier the system will return you to the
TEST sub-menu. This is the normal behavior of
the system, having the input of the non-active
amplifier terminated to a 50 Ohm load. If you
choose to terminate the input of the active
amplifier then the “Test TTA Offline” message
will appear. The RF signal path through the
tower top box will be interrupted and on-air sig-
nals will not be passed to the station receivers.
If left unattended, after about 9
minutes the system will switch out
of the test mode and back into the
normal mode of operation. On-air
signals will again pass through to
the station receivers.
3) Pressing the CANCEL button returns you to the
default display and on-air signals will again
pass through to the station receivers.
Un-Terminate LNA X
Allows you to completely disconnect the input of
either of the tower top amplifiers. The amplifier will
no longer be connected to either the antenna or its
internal 50 ohm load.
NOTE
NOTE
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