Motorola ASTRO 25 GTR 8000 Manual page 189

g Click Stop RSSI Measurement.
The Test Result Sheet calculates the Actual Sensitivity Term using Sensitivity Terminated – Test
Cable Loss - TTA Test Port Cable Loss - TTA Test Port Coupling Loss. This result is the
reference used to determine site degradation or de-sense in the following tests.
8 Test Rx De-sense for TTA Normal without other transmitters keyed. The degradation is < 2 dB
@ 700/800/900 MHz, < 6 dB @ 450 MHz, or < 10 dB @ 150 MHz.
CAUTION: This test and the following Rx De-sense TTA Normal with Transmitters Keyed
test cannot be performed accurately if the channel is in use within the coverage area of
the site (for example, a legacy system waiting for cutover).
a Configure the TTA so that the antenna port is connected to the antenna (normal operation).
b In CSS, click Start BER Measurement.
c If needed, readjust the Analyzer Generate RF Level for 5% ± 0.25% BER. Watch the CSS
BER for about 1 minute.
d Record the Analyzer Generate RF Level in the Gen Lvl Desense no Tx field of the result
sheet. The difference between this generator RF level and the level recorded in the Rx
Sensitivity with the TTA Terminated test is the site degradation/de-sense.
NOTICE: If the BER reading is not stable, there is an external interference or a
variable noise floor. Make a note on the Test Result Sheet that Channel X BER went
to Y% while performing this test.
The worksheet calculates the Degradation no Tx value. The degradation should be less than
specified at the beginning of this step.
• If the degradation is higher than recommended, consult with your system administrator to
determine what the impact could have on talk-in coverage.
• The Gen Lvl Desense no Tx level from this test becomes the benchmark for future PM
checks.
9 Test Rx De-sense for TTA Normal with transmitters keyed. The degradation is < 2 dB @
700/800/900 MHz, < 6 dB @ 450 MHz, or < 10 dB @ 150 MHz. This test is optional for
700/800/900 MHz.
CAUTION: This test cannot be performed if the RF channel under test OR any of the RF
channels being keyed up are in use with an operating system in the same coverage area.
a Key up the transmitters at the site.
WARNING: Verify that you have removed the power sensor from the Tx path before
keying up multiple transmitters.
b If needed, readjust the Analyzer Generate RF Level for 5% ± 0.25% BER.
c Record the Analyzer Generate RF Level in the Gen Lvl Desense w/Tx field of the FDMA
Chan sheet.
d De-key the transmitters at the site.
e In CSS, click Stop RSSI Measurement.
The result sheet calculates the Degradation with Tx value. If the degradation is higher than
recommended, consult with the System Engineer to determine what the impact could have on
talk-in coverage.
10 Test the Rx Noise Level with the TTA normal. This test establishes the noise floor of the receive
system:
a Turn the analyzer generator OFF.
Chapter 5: GTR 8000 Base Radio Optimization
MN003286A01-E
189