Tektronix 475A - Amplitude Comparison Measurements; Common-Mode Rejection

VOLTS/DIV and VAR VOLTS/DIV controls so the CH 2
MN EE display is about the same amplitude as the undesired
WITH UNWANTED | portion of the CH 1 display (see Fig. 17A).
LINE FREQUENCY 100
COMPONENT 90
3. Set the VERT MODE switch to ADD. Slightly
readjust the CH 2 VAR VOLTS/DIV control for maximum
cancellation of the undesired sígnal component (see Fig,
17B).
CH 2 SIGNAL
FROM LINE
FREQUENCY
SOURCE
SOURCE, = 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 VOLTS/DIV control is adjusted
SIGNAL WITH c to set the reference signal to an exact number of divisions.
LINE FREQUENCY
COMPONENT The unknown signal can then be quickly and easily
re compared with or adjusted to an exact number of
divisions.
Other unknown signals may be measured without
disturbing the setting of the VAR VOLTS/DIV control by
EEE establishing a vertical conversion factor and an arbitrary
defiection factor. The amplitude of the reference signal
must be known before a vertical conversion factor can be
Fig. 17. Common-mode rejection. established.
36 . 475A/DM44 Operators | @