Tektronix 2205, Operator'S Manual

Page: 56 / 91

Applications
More accurate phase measurements can be made by using the
horizontal magnifier function to increase the sweep speed with­
out changing the SEC/DIV variable control setting. To do this,
set the HORIZONTAL MAG to X I 0.
With the sweep speed increased 10 times (MAG set to X I 0), the
magnified horizontal graticule calibration will be 4 .5 ° per division
(45°/division divided by 10). Figure 3 -9 shows the same signals
illustrated in Figure 3 -8 , but horizontally magnified by a factor of
10
.
EXAMPLE. In Figure 3 -9 , the 10X magnified display results in a
horizontal difference of six divisions between the two signals.
Substituting the given values into the phase difference formula:
Phase Difference = 6 div x 4 .5 °/d iv = 27°.
CHANNEL 1 (REFERENCE) CHANNEL 2 (COMPARISON)
MEASURE
TIME FROM
A T O B
6 7 1 7 -
12
Figure 3 -9 . High-resolution phase difference.
3-16
2205 Operator's