Operating lnstructions~7B53A/7B53AN Operators
Mainframe
Operating
Modes
The
7B53A/7B53AN
can
be operated in a 7000-Series
Oscilloscope
which
has four
plug-in compartments, either
independently,
in the Alternate or
Chopped Horizontal
Modes,
or
as
a delayed sweep unit. However,
when the
7B53A/7B53AN
is
operated as
a delayed sweep unit, it
must
be triggered for
a CRT display. It cannot delay
another
time
base unit but it can delay
its
own internal
delayed
sweep. Refer to
the appropriate oscilloscope
manual
for additional mainframe horizontal operating
information.
APPLICATIONS
General
The
following information
describes the procedure and
techniques
for
making basic measurements with a
7B53A/
7B53AN
installed
in
a
7000-Series Oscilloscope. These
applications
are not described
in detail, since each
applica
tion
must
be
adapted to the requirements of the individual
measurement. This
instrument can also be used for many
applications not described
in this manual.
Contact your
local
TEKTRONIX
Field Office or representative for
assistance
in making specific measurements. The following
books
describe
oscilloscope
measurement techniques which
can
be adapted for use with this instrument.
J. Czech,
"Oscilloscope Measuring
Techniques",
Phillips
Technical Library, Springer-Verlag, New York,
1965.
2.
Set
the TIME/DIV OR DL'Y TIME switch and the
VARIABLE
control (Variable
Selector connector set to
Main Variable) so
one cycle of the signal covers an exact
number
of horizontal divisions. Do not change the
VARIABLE
control after obtaining the desired deflection.
This
display
can be used as a reference for frequency
comparison
measurements.
3. To
establish an arbitrary
sweep rate so the
period
(time for
one complete cycle) of an unknown signal can be
measured
accurately
at any setting of the TIME/DIV OR
DLY
TIME switch, the period of the reference signal must
be
known. If it is not known, it can be measured before the
VARIABLE
switch is set in step 2.
4.
Divide the period
of the reference signal (seconds) by
the
product
of the horizontal
deflection established in step
2
(division) and the setting of the TIME/DIV OR DLY
TIME switch. This
is the horizontal conversion factor:
Horizontal
Conversion
=
Factor
reference signal period
(seconds)
horizontal
TIME/DIV OR
deflection X DLY TIME
(divisions)
switch
setting
5.
To
measure the period of an
unknown signal dis
connect
the reference
signal and connect the unknown
signal
to
the vertical
unit. Set the TIME/DIV OR DLY
TIME switch
to a setting that provides sufficient horizontal
deflection to
make
an accurate
measurement. Do not
readjust
the VARIABLE
control.
John
D. Lenk, "Handbook of Oscilloscope Theory
and Applications",
Prentice-
Hall, Inc. Englewood Cliffs,
N.J.,
1968.
Charles
H. Roth, Jr.,
"Use of the Oscilloscope",
Programmed
Text,
Prentice-Hall, Inc., Englewood Cliffs,
N.J.
1970.
6.
Measure
the horizontal
deflection in divisions and
calculate
the period
of the
unknown signal using the
following
formula:
Period
(Seconds)
J.
H. Golding, "Measuring Oscilloscope", Trans
atlantic,
1971.
TIME/DIV OR
DLY
TIME
setting
horizontal
X conversion X
factor
horizontal
deflection
(divisions)
Comparison
Measurement
Techniques
Sweep
Rates.
To
establish
an arbitrary horizontal sweep
rate
based
upon
a specific reference frequency proceed as
follows:
1.
Connect the
reference
signal to the input of the
vertical
unit. Set the Volts/Division switch
of
the vertical
unit for four
or five
divisions of vertical deflection. Obtain
a triggered display.
Example.
Assume
a
reference signal frequency
of 455
hertz
(period 2.19 milliseconds), a TIME/DIV OR DLY
TIME switch
setting of .2 ms, and the VARIABLE control
adjusted
to provide a
horizontal deflection of eight divi
sions.
Substituting
these values in the horizontal conversion
factor formula
(step 4) :
Horizontal
Conversion
=
Factor
2.19
milliseconds
.2
ms
x
8
=
1.37
@1
REV.
APR
1974
1-15
