Table of Contents
Advertisement
Model 181A/AR
establishes the CRT
in a condition for variable per-
sistence display of a signal which can later be stored.
Use the minimum INTENSITY and maximum PERSIS-
TENCE
required to obtain the desired display.
3-171. MAX WRITE.
Operation in the Max Write mode
(MAX W.) provides a more rapid build-up and display
of fast single-shot signals.
Since the background il-
lumination also increases more rapidly, the CRT con-
trast level and storage time are reduced.
3-18. ERASE.
Depressingthe ERASE push button will
remove stored signals from the CRT when either the
WRITE
or MAX W push buttonisdepressed.
Stored
or written displays that remain visible after erasure,
may require the ERASE push-button be held depress-
ed for approximately
30 seconds.
3-19. PERSISTENCE ANDINTENSITY. These controls
determine the viewing time of a signal being displayed.
The INTENSITY sets the brightness of the trace as it
is written.
The PERSISTENCE
control is used
to
establishthe desired duration of signal viewing without
rewriting.
Itaccomplishes this by varying the rate at
. Which the displayed signal is erased.
3-20. TRACE ALIGN.
The TRACE ALIGN adjustment
controlcompensatesífor external magnetic fields that
may affect the alignment of the horizontal
trace with
the graticule.
Thealignment should be checked when
the instrument is moved to a new location and the ad-
justment made whenever
necessary.
3-21. FIND BEAM.
Off-screen positioning of the CRT
beam
may
occur
due to initial improper control set-
tings or a very high dc input signal.
The beam may
be brought
back
on screen
by depressing
the
FIND
BEAM push button.
Adjustthe horizontaland vertical
position controls to center the beam (refer to the plug-
in manuals).
Adjust the INTENSITY controlto obtain
a visible trace.
. 9-22. MAGNIFIER,
Whenthe DISPLAY control is set
to EXT CAL,
the MAGNIFIER provides switched gain
levels
in the horizontal amplifier of X1, X5, or X10.
In the X5 or X10 positions, the horizontal gain is in-
creased to provide an amplified display of five or ten
times, respectively.
Theinsertion ofa 1v signal into
the EXT INPUT jack will result ina 1-division deflec-
tionin X1, 5-division in X5, anda 10-division deflec-
tion in the X10 position.
8-23. DISPLAY.
This control determines
the input
signaltothe horizontalamplifier.
With the DISPLAY
controlsetto EXT CAL,
the external horizontal input
signal is coupled directly to the horizontal amplifier.
As the DISPLAY control is rotated counterclockwise,
the external signal is increasingly attenuated.
When
the DISPLAY control is fully counterclockwise (INT),
the externalinputsignalis disconnectedandthe inter-
nal sweep is coupled directly to the horizontal ampli-
fier.
3-24. CALIBRATOR. The 1 kHz square-wave calibrator
output signal of 10v can beused for vertical sensitivity
calibration and for probe
compensationadjustment. The
CALIBRATOR output amplitude is accurate within: 1%.
Rise time of the square-wave output is less than 3 u sec.
02612-2
Section IH
Paragraphs 3-17 to 3-37
3-25. REAR PANEL.
3-26. OUTPUTS.
Main and delayed sweep and gate
signals are available at rear panel BNC connectors
of
the Model 181A/AR.
These outputs are providedfrom
separate isolationamplifiers which can supply 3 ma and
will drive impedances
as low as 1000 ohms without
distortion.
The plug-ins used in the Model 181A/AR
and the control settings employed deter mine the out-
put signals available.
3-27. Z-AXIS INPUT.
Anexternal signal can be util-
- izedfor control of CRT intensity.
A rear~panel mounted
BNC connector permits a direct connectionto the CRT
intensity gate amplifier.
A signal of approximately
42v, dcto 15 MHz,
isrequired to blank
a beam
of nor-
mal intensity.
Input of a negative signal c can be used
for beam intensification.
3-28. AC LINE INPUT.
A three-conductor
ac input
jack is providedfor power input.
Also located on the
rear panelis the 115/230v slide switch andthe required
fuses for 115 vac and 230 vac operation.
3-29.
INTERNAL.
3-30. PHASE/BANDWIDTH.
'TheModel181A/AR can
also be usedfor phase measurements.
Positioning the
.PHASE/BANDWIDTH switch to PHASE
causes
the
horizontal input signal to be delayedthe same amount
of time as the vertical input signal.
NOTE
Make certain the control is returned to
the Bandwidth position after making phase
measurements.
i
3-31.
PLUG-IN
UNITS.
3-32. The Model 181A/AR Oscilloscope requires hori-
zontaland vertical plug-ins.
The deflection sensitivity
of the CRT may vary slightly with differentunits.
Plug-
in units should be calibrated when first installed
or
when shifted between oscilloscopes.
The horizontal
and vertical plug-in units must be locked together prior
to insertion into the Model 181A/AR mainframe.
Con-
sult the respective plug-in Operating andService Man-
ual for operation and capability information.
3-33. MAGNETIC
INTERFERENCE.
3-34. The CRT is provided witha mu- metal shield for
protection against magnetic fields.
Duetothe sensi-
tivity ofthe CRT, it is possible that the strong magnetic
fieldfrom nearby motors, ac linetransformers,
etc.,
may
still result in a noticeable beam deflection)
In
this event,
reorient
or relocate
the instrument with
respect to the interfering device.
l
3-35.
OPERATING
CONDITIONS.
3-36. DEFINITIONS.
3-37. Several words and phrases, the definition of.
which may vary slightly from common usage, are used
3-3
Advertisement
Table of Contents
