2635 manual - BK Precision

accordingly when moving towards the left screen edge. The
outermost left line therefore corresponds to 0MHz.
(16) ZERO SPAN:
With the ZERO SPAN button a SPAN of 0 Hz is being selected. If
a SPAN of 0Hz is selected, the analyzer performs as a selective
level meter, which can be calibrated via the Center Frequency
(CENTER FREQ.). The display of the measured level is displayed
via a horizontal line. The ZERO SPAN mode is activated by pushing
the ZERO SPAN button. Press again to revert to previous span.
Above illustration explains the terms SPAN, Center Frequency,
Extent of Scale, and Attenuator.
The height
of the „window“ is limited to 80dB due to the extent of the scale,
however, the display range can be shifted up and down by
switching on or off the attenuators and by setting another
reference level. The width of the displayed range is set via the
SPAN of the analyzer, which may comprise of the entire gray
area or only part of it. The location of this range is set via the
Center Frequency (CENTER FREQ.). It is always advisable to
select the precise Center Frequency and the SPAN as low as
possible (resolution of display) so the signal can be viewed easily.
An unnecessarily high SPAN has a rather negative effect.
Remark:
The HM5012/5014 spectrum analyzer is internally programmed
for always choosing the appropriate sweep time related to the
span, resolution bandwidth and video bandwidth, wherever
possible. The UNCAL indicator in the readout will be visible in
Subject to change without notice
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