Tektronix 3B5, Instruction Manual

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Operating Instructions— Type 3B5
Fig. 2-16. Accurate phase-difference measurement with increased
sweep rate.
More Accurate Phase Measurements
More accurate dual-trace phase measurements can be
made by increasing the sweep rate (without changing the
VARIABLE control setting as established in the preceding
method). One of the easiest ways to increase the sweep
rate is with the DLY'D SWP MAG switch. The magnified
sweep rate is determined by dividing the sweep rate obtained
previously by the magnification.
Example. If the sweep rate were increased 10 times with
the magnifier, the magnified sweep rate would be 45° 4- 10
= 4.5° /division. Fig. 2-16 shows the same signals as used
in Fig. 2-15 but with the DLY'D SWP MAG switch set to
X10 (DELAY dial set to 0.92). With a horizontal difference
of 6 divisions, the phase difference would be:
horizontal ,
Phase Difference = difference X magnified sweep
..... rate ( degrees/div )
(divisions)
Substituting the given values:
Phase Difference = 6 X 4.5°
The phase difference would be 27°.
2-20