206 Chapter 2
Front-Panel Key Reference
Trig
Trig
Accesses the menu of keys that allow you to select the sweep mode and
trigger mode of the analyzer.
Free Run New sweep starts as soon as possible after the current sweep ends.
Key Access:
Trig
Video
Activates the trigger condition that allows the next sweep to start if the
detected RF envelope voltage rises to a level set by the video trigger
level. When
Video is pressed, a line appears on the display. The analyzer
triggers when the input signal exceeds the trigger level at the left edge
of the display. You can change the trigger level using the step keys, the
knob, or the numeric keypad
Key Access:
Trig
NOTE This function is not available when the Resolution Bandwidth is less
than 1 kHz. If a Resolution Bandwidth less than 1 kHz is selected while
in Video Trigger mode, the Trigger mode changes to Free Run.
Line Activates the trigger condition that allows the next sweep to be
synchronized with the next cycle of the line voltage.
Key Access:
Trig
NOTE Line trigger is not available when operating from a dc power source.
External
Pos Neg
Activates the trigger condition that allows the next sweep to start when
the external voltage (connected to GATE TRIG/EXT TRIG IN on the rear
panel) passes through approximately 1.5 volts. The external trigger
signal must be a 0 V to +5 V TTL signal. This function also controls the
trigger polarity (for positive or negative-going signals).
Key Access:
Trig
Trig Delay
On Off
Allows you to set and turn on or off a delay, during which the analyzer
will wait to begin a sweep after receiving an external trigger signal.
This function is not available when Gate is on. Trig Delay is active when
External is selected.
Key Access:
Trig, More
NOTE This function is not available in Free Run or Video Trigger modes.