Bird Technologies 429-83H-01 Series-Manual - Manual (Page 33)

TX RX Systems Inc. Manual 7-9439-6 09/03/09 Page 25
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 buttons 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.
1) From the TEST sub-menu display use the
ARROW buttons to scroll over to the UNTERM
LNA “A (or) B” menu choice and press the
ENTER button.
2) If you choose to un-terminate the input of the
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 active ampli-
fier un-terminated. If you choose to un-termi-
nate the input of the non-active amplifier then
the “Test TTA Offline” message will appear.
The RF signal path through the tower top box
will not be interrupted and on-air signals will
continue to 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.
3) Pressing the CANCEL button returns you to the
default display.
SYSTEM TROUBLESHOOTING
System problems fall under these main categories:
1) Performance problems characterized by poor
receiver sensitivity and possibly accompanied
by activation of the alarm system. RF interfer-
ence or component problems can be the cause.
2) Hardware problems.
3) Power Supply.
Performance Degradation
Most performance difficulties manifest as an inter-
mittent or continuous loss of effective receive
channel sensitivity sometimes accompanied by
audible interference in FM systems or dropouts in
digital radios. Sensitivity loss on a continuous basis
is more likely to indicate a hardware problem which
may produce an alarm condition. Table 9 is a trou-
bleshooting guide that is read from top to bottom to
narrow down the possible causes. The guide con-
tains both symptoms and suggested tests as out-
lined earlier in this manual. Both the measurement
of sensitivity and observation of the output spec-
trum are key tests along with the presence of any
alarm condition.
Hardware Problems
Two of the most common reasons for TTA alarms
are direct lightning strikes and vandalism. Even
though the system is designed with redundancy so
that likely-to-fail components have backups, it is
possible to shut the system down, especially if a
NOTE
NOTE
NOTE