Tektronix SC 502, Instruction Manual

Page: 26 / 127

Sweep Magnification
The sweep magnifier expands
the
sweep by
a factor
of
ten.
The
center division
of the
unmagnified displ ay is the
portion visi ble on the screen in
magnified
form. The
equivalent
length
of
t
h
e magnified
sweep is
more t han
1 00
divisions. Any 1 0 division portion of the
magnified
sweep
can
be viewed by
ad
j
usti ng
the horizontal POSITI ON
control to bring
the
desired portion i nto the viewi ng area.
To
use the magnified sweep. fi rst move th
e
porti on of
the
display which
is
to
be
expanded
to the center of the
graticule. Then
pul l the SWP MAG switch to its out
position.
Use the
horizontal POSI TIO N c
o
n
t
r
o
l
to
move
the
magnified
portion to the desired position.
When the
SWP MAG switch
is
set to on.
the s
w
e e
p rate
is determ ined by dividing the SECONDS/DI V switch
setti ng by 1 0.
For example.
if
the
SECONDSIDIV
switch is
set to .5 11. the
magnified
sweep
rate
is 0.05 pS/
div.
x-Y Operation
In some appl i cations. it is desirable to display one
signal
versus another
(X-Y) rather than
agai nst
the
i nternal
time base. The AM P
position
( f u ll y ' countercl ockwise) of
the SECO N DS/DIV switch
provides
a means
for applying
an
external signal to the horizontal amplifi er for this type
of displ ay.
NO TE
The
CHOP position
of the
MODE
switch must be
used for dual vertical displays.
The AL
T position of
the
MODE
switch will not produce a correct display.
Do
not exceed the
hori zontal
scan area of the g
r a
ticu
l
e
I n the X-V mode of operation.
This mode
can be
u se
d
to
measure
phase
differences
of
signals
up
to about
50 kHz .
Above
this
frequency. the phase shift i n the system
makes
phase
m
e
a
s
u r e
m
e
n
t
difficult.
BASIC OSCILLOSCO PE APPLICATIONS
The
fol l owing information descri bes the
techniques for
making
basic measurements.
These
applications
are
not
descri bed i n detai l.
si nce
each appli cation
must be
adapted to
the
requirements of the i ndividual
measur&­
ment.
Contact
your local Tektronix Fiel d Offi ce or
representative
for additional assistance.
Peak-to-Peak Voltage Measurements-AC
To make peak-to-peak voltage measurem ents, use the
following procedure
:
@ MAY
1 980
Operating Inltructlonl-SC 502
1. Set the desired
channel
AC-GND-DC switch to
GND
and
connect the
sig nal
to the
i nput
connector.
2. Set the
desired
channel AG-G N D-DC switch to AC
and
set the channel
VOL TS/DIV
switch to display about 5
or
6 vertical
divisions
of the
waveform.
Check
t
h a
t
the
vari able V O L
TS/DI
V control for the
channel
is i n the
ful ly
clockwise position.
3.
Adjust
the time-base triggering control s for
a stable
dispiay
and set the SECONDS/OI V
switch to displ ay
several
cyc l es
of the waveform.
4. Turn the
c hannel PO S I T I ON
control
so
that the
lower portion of the waveform coi ncides wit h one of the
graticule I i nes below
the
c e n t
e
r
horizontal I i ne,
and
the top
of the
waveform
is i n the viewi ng area. Move the
displ ay
with the horizontal POSITI ON control so that
one
of the
upper peaks
is
aligned
with
the center
vertical reference
line (see F.ig. 2-3) .
----f---
V.rtlcal
.flectlon
I
'o.I,lon te '
cente'
... rlleal Ii ...
1000· 1 8
Fi g. 2- 3. M
•••
urlng pe.k-Io--pe.k yo/llge of
•
wlIYeform.
5. Measure
the vertical
deflection
from
peak
to
peak
(divisions) .
NO TE
This technique may
also be
used to make
measurements between any two pOints on the
waveform, rather than peak to peak.
6.
M ulti ply
the
d
i s
ta n c e
(in divisions)
measured
i n step
5 by the
channel
VOL TS/OI V switch
setti ng. Also
i ncl ude
the attenuati on factor of the probe, if one is
used.
2-9