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Chapter 4 123
Making Measurements
Making the Adjacent Channel Power (ACP) Measurement
Recommended Offset Frequencies and Reference Bandwidths
While the user sets the specific offsets and reference bandwidths, the
radio specifications recommend some common setups as shown in the
following table.
Making the Measurement
The factory default settings provide a good starting point. For special
requirements, you many want to change some of the settings. Press
Meas Setup, More, Restore Meas Defaults at any time to return all
parameters for the current measurement to their default settings.
Select the desired center frequency as described in the “Changing the
Frequency Channel” section.
Press
MEASURE, ACP to immediately make an adjacent channel power
ratio measurement.
To change any of the measurement parameters from the factory default
values, refer to the “Changing the Measurement Setup” section of this
measurement.
Results
The following figure shows an example result of ACP (Total Pwr Ref)
measurements in the bar graph window. The absolute and relative
power levels on both sides of the carrier frequency are displayed in the
graphic window and text window.
Table 4-3 ACP Setup Recommendation
Band Test Unit
Offset
Frequency
Reference
(Integration)
Bandwidth
Result
Reference
IS-95-A Mobile ±900 kHz 30 kHz Total Power
in 1.23 MHz
±1.98 MHz 30 kHz
Base ±750 kHz 30 kHz PSD Ref
±1.98 MHz 30 kHz
J-STD-008 Mobile/Base ±885 kHz 30 kHz Total Power
in 1.23 MHz
±1.25625 MHz 12.5 kHz
±2.75 MHz 1 MHz