User's Manual

Manual 7-9415-1.4 Page 19TX RX Systems Inc. 08/31/06
61-65-50 UserMan page 19 of 24
predetermined points and key their radios.
Record the level of these signals as observed
on the analyzer and also record the location of
the person transmitting. In this way, a map of
the systems performance can be generated.
4) For signals coming from a fixed antenna or sta-
tion, record the level of all the desired incoming
signals for future reference.
MAINTENANCE AND REPAIR
Signal boosters manufactured by TX RX Systems,
Inc. can perform for years with little maintenance
and repair. However, if the amplifiers are subjected
to excessively high signal levels, power surges or
lightning strikes, failures may occur. The following
procedures may be followed for detecting a mal-
functioning unit or as part of a periodic mainte-
nance program.
1) The heatsink area should be cleared of dust
and debris.
2) Inspect the unit to see that the two power sup-
ply LED DC indicators are lit (remove any dust
or debris that may obscure the LEDs). This will
verify that DC power is flowing properly. Check
all hardware for tightness.
3) Compare system performance to initial perfor-
mance levels measured when the system was
first installed. The lack of signal can be traced to
a malfunctioning amplifier by progressive signal
monitoring from the output (far end) to the input
end of the system noting the area where the
signal returns to normal level. The next amplifier
toward the output end of the system will proba-
bly be the one that failed.
or
Measure the gain at any convenient frequency
in the working frequency band to verify that the
performance is still within specifications.
Power Amplifier Replacement
The SB II power amplifiers are field replaceable.
Follow the steps listed below in sequential order.
The required tools are a #1 Phillips screwdriver
and a 5/16” open-ended wrench.
Figure 10: Remove 14 mounting screws to detach amplifier assembly from cabinet.
Remove Screws
Remove Screws
Remove
Screws
Remove
Screws