Tektronix 47E5A

CH 1 SIGNAL
J .:"
WITH UNWANTED
LINE FREQUENCY 100
COMPONENT 90
CH 2 SIGNAL
FROM LINE
FREQUENCY
SOURCE
(INVERTED)
....
10/
r
j
1' ....
./
--
--
,"
.......
",,"
.......
......
"-
(A) CH 1 AND CH 2 SIGNALS.
.-
SIGNAL WITH
~-
-...
. .
..
"':'
"..-
- ..
' ...
,
,
./
V
-r-
- -
LI ~~~~6~~ ~ ~ C Y ~+t++++j-t+<*ft-+++t++>+t>+++-t++++tH+<>tH++t++++i
CANCELED
OUT
r- - - ------ -- -- ----
'~--+--+--~~--~~---r~r--r~
L
(6) RESULTANT SIGNAL.
1738·19
Fig. 17. Common-mode reJection.
VOL TS/DIV and VAR VOL TS/DIV controls so the CH 2
display is about the same amplitude as the undesired
portion of the CH 1 display (see Fig. 17A).
3. Set the VERT MODE switch to ADD. Slightly
readjust the CH 2 VAR VOL TS/DIV control for maximum
cancellation of the undesired signal component (see Fig.
178).
AMPLITUDE COMPARISON
MEASUREMENTS
If comparisons of an unknown signal with a reference
signal are repetitious (e.g., on an assembly line test) it is
possible to obtain more accurate easily read
measurements if the VAR
VOL TS/DIV control is adjusted
to set the reference signal to an exact number of divisions.
The
unknown signal can then be quickly and easily
compared with or adjusted to an exact number of
divisions.
Other unknown signals may be measured without
disturbing the setting of the VAR VOL TS/DIV control by
establishing a vertical conversion factor and an arbitrary
deflection factor. The amplitude of the reference signal
must be known before a vertical conversion factor can be
established.
36
475A/DM44 Operators
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