Operating instructions

OPERATING MANUAL 2945A
46882-311D 3-81
The soft keys have the following functions, (top to bottom):-
[ ]
Increases Y Sensitivity
by one range per key press.
[ ]
Decreases Y Sensitivity
by one range per key press.
[ ]
Increases Time/Division
by one range per key press.
[ ]
Decreases Time/Division
by one range per key press.
[Scope/Bar]
Steps to Expanded display or
Bar chart display
[Return]
(Standard)
Returns display and menu to
Tx TEST, Rx TEST or AF Test.
[Persistence]
(Expanded)
Steps persistence setting through
Off, Low Med High Inf.
The vertical position of the oscilloscope trace can be adjusted using the POSITION rotary control.
The horizontal sweep trigger can be set for repetitive or single sweep, set by the scope mode keys
(Item 15 on fig 3-1, Front panel).
With repetitive mode selected, the trace will free-run, re-triggering on the positive-going edge of
the signal, at the end of each sweep. In the absence of a signal the trace will auto-trigger.
With single sweep selected, the first positive going signal will trigger a sweep. The [SINGLE]
key must be pressed to re-arm the trigger circuit before another sweep can be triggered.
Expanded display
With the expanded display selected, the area of the display available for digital readings is
limited. The following table shows the data that can be displayed in each test mode.
Tx Test Rx Test AF Test
Tx FREQ
OFFSET
POWER
MOD FREQ AUDIO FREQ AUDIO FREQ
FM/AM LEVEL LEVEL LEVEL
SINAD, S/N,
DISTORTION
SINAD, S/N,
DISTORTION
SINAD, S/N,
DISTORTION
Persistence
The persistence of the scope trace can be selected to suit the user’s requirements. The expanded
display has a [Persistence] key, which steps through the available persistence settings. The
persistence setting is effective on both the expanded and standard oscilloscope displays but can
only be set from the expanded display.
The following table shows the available settings and the approximate decay times.
Setting Decay time (seconds)
Off 0
Low 1
Med 3
High 8
Inf Infinite