User Manual

Calibrating Output Power
68P09255A57-2
Aug 2002
SC4812ET Optimization/ATP Manual Software Release R16.1.x.x
PRELIMINARY
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Calibrating Output Power
Power Calibration
This procedure is a guide to expanding your system with multiple
carriers while the system remains in service. This procedure also allows
you to perform on site maintenance (replace defective boards and
recalibrate) while the remainder of the site stays in service.
Motorola recommends that you perform this procedure during a
maintenance window.
This procedure cannot be performed on BTSs with 4-to-1 combiners.
The procedure can only be performed on one side of the BTS at one
time. That is, LPAs 1, 2 ,3, 7, 8, 9 (feed antennas 1, 2, 3) can be
calibrated while LPAs 6, 7, 8, 10, 11, 12 (feed antennas 4, 5, 6) remain
in service and vice versa.
Equipment Warm up
NOTE
Calibration of the communications test set (or equivalent test
equipment) must be performed at the site before calibrating the
overall test set. Calibrate the test equipment after it has been
allowed to warm-up and stabilize for a minimum of 60 minutes.
CAUTION
If any piece of test equipment (i.e., test cable, RF adapter) has
been replaced, re-calibration must be performed. Failure to do so
could introduce measurement errors, causing incorrect
measurements and degradation to system performance.
Power Delta Calibration Introduction
The In-service calibration procedure has several differences from a
normal calibration procedure. One of these is the use of a spectrum
analyzer instead of a power meter to measure power. Power meters are
broadband measurement devices and cannot be used to measure power
during In-service Calibration since other carriers are operating. A
spectrum analyzer can be used because it measures power at a given
frequency. However, measuring power using a spectrum analyzer is less
accurate than using a power meter. Therefore, you must compensate for
the difference (delta) between the power meter and the spectrum
analyzer.
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