Bird Technologies 429-83H-01 Series-Manual - Manual (Page 30)

TX RX Systems Inc. Manual 7-9439-6 09/03/09 Page 22
Measuring Effective Sensitivity
(Antenna Connected)
The Effective system sensitivity should be taken
under normal conditions as well as with all trans-
mitters producing full power. All transmitters keyed
will show the worse case situation. To test the sys-
tems effective sensitivity through the test port with
the antenna connected to the amplifiers perform
the following steps;
1) The signal generator and SINAD meter (or bit
error rate meter if appropriate) should be con-
nected to the system as shown in Figure 18.
2) Under normal conditions the antenna is con-
nected to the amplifiers so no software interac-
tions are required. Be sure the signal generator
is setup for a 3 KHz deviation with a 1000 Hz
tone (analog) or proper pattern for BER testing.
3) Adjust the signal strength from the signal gener-
ator until the 12 dB SINAD or required BER
point is acquired. This determines the systems
sensitivity in the presence of site noise. Record
this value in the MCU’s memory for future use.
4) From the default display, use the ARROW but-
tons to scroll to the SENSITIVITY menu choice
then press the ENTER button.
5) Use the ARROW buttons to scroll over to the
REFERENCE W/ANT menu choice and press
the ENTER button.
6) Use the ARROW buttons to dial in the effective
sensitivity value and press the ENTER button to
save the information in memory. By storing the
sensitivity value at the time of installation it can
be compared with future tests and used as an
indication of system degradation or failure.
The sensitivity value measured in
step 3 is less (45 dB plus the Test
Line loss) than the actual sensitiv-
ity value.
NOTE
Status LED Possible Amplifier Status Form-C Contact Status
Tower top Amplifier A
Green Selected; normal current Normal
Off Not selected; normal current Normal
Red Failure: Very abnormal current; can only be selected if amplifier B is
also in Alarm
Alarm contacts change state
Red Failure: Extremely abnormal current; cannot be selected Alarm contacts change state
Tower top Amplifier B
Green Selected: normal current Normal
Off Not selected; normal current Normal
Red Failure: Very abnormal current; can only be selected if amplifier A is
also in Alarm
Alarm contacts change state
Red Failure: Extremely abnormal current; cannot be selected Alarm contacts change state
Base (Distribution) Amplifier
Green Normal current Normal
Red Failure: Very abnormal current Alarm contacts change state
Table 7: Amplifier status troubleshooting guide.