Sweep Controls - Tektronix 7B92A Maintenance Manual

Operating Instructions-7B92A
AC LF REJ: Rejects dc and attenuates signals below30
kilohertz. Accepts signals between 30 kilohertz and 500
megahertz.
AC HF REJ. Rejects dc and attenuates signals above
50 kilohertz. Accepts signals from 30 hertz to 50
kilohertz.
DC: Accepts all signals from dc to 500 megahertz.
(6) SOURCE Switches
Select the triggering source.
indicated by lighted pushbutton.
INT: Trigger signal obtained internally from amplifier
plug-in unit of oscilloscope.
LINE: Trigger signal obtained internally from the line
voltage applied to the oscilloscope.
EXT: Trigger signal obtained from an external source
applied to the MAIN TRIG IN connector.
EXT Þ 10:
Trigger signal obtained from an external
source applied to the MAIN TRIG IN connector. In this
position, the external signal is attenuated before it is
applied to the trigger circuit.

Sweep Controls

(7) TIME/DIV OR DLY TIME
Selects the basic sweep rate for normal sweep operation
and selects the delay time (multiplied by the DELAY
TIME MULT dial setting) when operating in the Alternate
or Delayed sweep modes. The VARIABLE control must
be in the CAL (knob in) position for calibrated sweep
rate.
(8) DLY'D Time/Division
Selects the delayed sweep rate for operation in Delayed
and Alternate sweep modes.
must be in the CAL (knob in) position for calibrated
sweep rate.
Four display modes can be selected by the following
switch settings:
Normal Sweep: A normal sweep is selected when the
TIME/DIV OR DLY TIME switch and the DLY'D
Time/Division switches are locked together at the same
sweep rate. The DLY'D Time/Division knob must be
pressed in for normal sweep mode. Calibrated sweep
rates from 0.2 second/division to 0.5 nanosecond/-
division can be selected
Selected source is
The VARIABLE control
ALT Sweep: The Alternate mode is selected when the
DLY'D Time/Division switch is pulled out and rotated
clockwise and the TRACE SEP control is turned
clockwise from the ALT OFF position. In this mode, the
delaying sweep is displayed (with an intensified zone
during the time that the delayed sweep runs) alternately
with the delayed sweep.
Intensified Sweep: The Intensified mode, a function of
the delaying and delayed sweeps is selected when the
DLY'D Time/Division switch is pulled out and rotated
clockwise, and the TRACE SEP control is rotated fully
counterclockwise to the ALT OFF position (see Fig. 1-3).
In this mode, a portion of the delaying sweep is
intensified during the time that the delayed sweep
generator runs.
DLY'D Sweep: The Delayed sweep mode is selected
when the DLY'D Time/Division switch is pulled out,
rotated for the desired delayed sweep rate, and then
pushed in. In this mode, the delayed sweep is displayed
at a rate determined by the DLY'D Time/Division switch
at the end of each delay period, as selected by the
TIME/DIV OR DLY TIME switch and the DELAY TIME
MULT dial setting.
(9) VARIABLE
Two-position switch actuated by the VARIABLE control
to select calibrated or uncalibrated sweep rates. In the
CAL position (knob in) the VARIABLE control is
inoperative and the sweep rate is calibrated.
pressed and released, the knob moves out to activate
the VARIABLE control for uncalibrated sweep rates. The
sweep rate in each TIME/DIV OR DLY TIME switch
position can be reduced at least to the sweep rate of the
next slower position. The VARIABLE control will operate
with either the delaying or delayed sweep by means of
the internal Time/Div Variable Selector.
(10) POSITION Control
Positions the display horizontally on the graticule.
(11) CONTRAST Adjustment
Varies the relative brightness of the intensified portion of
the delaying trace when in the Alternate mode.
(12) TRACE SEP/ALT OFF Control
This control vertically positions the delaying sweep
display up to 3.5 divisions above the delayed sweep
display when in the Alternate mode.
position allows the Intensified sweep mode of operation,
permitting the display of an intensified portion of the
delaying sweep.
1-4
When
The ALT OFF
REV B, JUN 1978