Tracking Generator Unleveled Condition; 4-10. Measure The Rejection Range With Delta Markers - HP 8590 E-Series User Manual

Figure

4-10. Measure the Rejection Range with Delta Markers

Tracking Generator Unleveled Condition

When using the tracking generator, the message TG UNLVL may appear. The TG UNLVL message
indicates that the tracking generator source power (SRC PWR ON OFF ) could not be maintained
at the user-selected level during some portion of the sweep. If the unleveled condition exists
at the beginning of the sweep, the message will be displayed immediately. If the unleveled
condition occurs after the sweep begins, the message will be displayed after the sweep is
completed. A momentary unleveled condition may not be detected when the sweep time is
small. The message will be cleared after a sweep is completed with no unleveled conditions.
The unleveled condition may be caused by any of the following:
Start frequency is too low or the stop frequency is too high. The unleveled condition is likely
n
to occur if the true frequency range exceeds the tracking generator frequency specification
(especially the low frequency specification). The true frequency range being swept may be
significantly different than the start or stop frequency annotations indicate, depending on
other spectrum-analyzer settings, especially the span (see specifications and characteristics in
your calibration guide for your instrument). For better frequency accuracy, use a narrower
span.
. Tracking peak may be required (use TRACKING PEAK ).
setting).
The source power may be set too high or too low, use SRC PWR ON OFF to reset it.
n
The source power sweep may be set too high, resulting in an unleveled condition at the end
n
of the sweep. Use PWR SWP ON OFF to decrease the amplitude.
4-12 Making Measurements
PEAK
LOG
1 0
- 6
S C FC
C E N T E R 4 4 3 6 MHz
S P A N 5 0 0 . 0 MHz