Tektronix 2246 - Page 62

Measuremen rrocesses and APPICAUOTIST72£230 VPRETALUTS
CH 2 input must be in phase with the frequency com-
ponent to be canceled from the CH 1 signal.
4. Turn on CH 1 and CH 2 VERTICAL MODE.
5. Set both VOLTS/DIV switches to produce displays
of about four to five divisions in amplitude.
6. Adjust the CH 2 VOLTS/DIV switch and VAR con-
trol so that the CH 2 display is about the same amplitude
as the component to be canceled in the CH 1 waveform
(see Figure 6-18A).
7. Select both ADD and CH 2 INVERT. Turn off the
CH 1 and CH 2 displays and slightly readjust the CH 2
VOLTS/DIV VAR control for maximum cancellation of the
line-frequency component (see Figure 6-188).
8. The SEC/DIV setting may be set to a faster sweep
speed to expand the waveform, and the display amplitude
may be increased by advancing both VOLTS/DIV switches
and readjusting the VOLTS/DIV VAR controls as neces-
sary to maintain cancellation of the undesired signal
component.
6-22
tat an PAGERS ESSE E OEE LONE NMOL LO BTL LO EET SE eA ee
CH 1 SIGNAL
WITH UNWANTED
LINE FREQUENCY
COMPONENT
CH 2 SIGNAL
FROM LINE
FREQUENCY
SOURCE
SIGNAL WITH
LINE FREQUENCY
COMPONENT
CANCELED
OUT
Figure 6-18.
{8} RESULTANT SIGNAL.
3832-15
Eliminating common-mode signals.
ne