Frequency
Markers
The sweep generator provides up to 20 independent,
pre-settable markers, F0-F9 and M0-M9, that can
be used in the analog and step sweep frequency
modes for precise frequency identification. Marker
frequency accuracy is the same as sweep frequency
accuracy. The markers are visible on a CRT display.
The 681XXB generates two types of markers.
Video Marker–produces a pulse on a CRT dis-
play at each marker frequency. The video
marker is either a +5V or a –5V pulse at the
rear panel. The polarity of the video marker
pulse is selectable from a system configuration
menu.
Intensity Marker–produces an intensified
dot on a CRT display at each marker fre-
quency. Intensity markers are only available
in the analog sweep frequency mode and are
obtained from a momentary dwell during the
sweep at each marker frequency.
To output markers during a sweep you must first se-
lect (tag) the marker frequencies from the Marker
List menu, then turn on the marker output.
To go to the Marker List menu from an analog or
step sweep frequency menu, press
FREQUENCY
CONTROL
The Sweep Frequency Control menu (below) is dis-
played.
To go to the Marker List menu from this menu,
press
Marker List
. The Marker List menu, shown
on the next page, is displayed. This menu lets you
tag or edit marker list frequencies and turn the
markers on/off.
LOCAL (FRONT
SWEEP FREQUENCY
PANEL) OPERATION
OPERATION
3-32
681XXB OM
