Kenwood CS-2110 Instruction Manual page 23

PHASE DIFFERENCE MEASUREMENTS
T h i s procedure is useful in measuring the phase differ-
ence of signals of the s a m e frequency.
1. Apply the t w o signals to channel 1 and channel 2
INPUT jacks, selecting the vertical MODE s w i t c h to
D U A L and choosing either C H O P or A L T mode.
2. S e t the S O U R C E s w i t c h to the signal w h i c h is leading
in phase and use V O L T S / D I V control to adjust the sig-
nals such that they are equal in amplitude. Adjust the
other controls for a normal display.
3. Use the S W E E P T I M E / D I V and A V A R I A B L E controls to
adjust the display such that one cycle of the signals o c -
cupies 8 divisions of horizontal display.
Use the y POSITION control to bring the signals in the
center of the screen.
Having s e t up the display a s above, one division now
represents 45° in phase.
4. Measure the horizontal distance between correspond-
ing points on the t w o waveforms.
Using the formula:
Phase difference = horizontal distance (div) x 45°/div
1 c y c l e
Reference signal
•Comparison
signal
Fig. 19
[ E X A M P L E ]
For the example s h o w n in Fig. 1 9 , the horizontal distance
is 1.7 divisions.
Substituting the given value:
T h e phase difference = 1.7 (div) x 4 5 ° / d i v = 76.5°
The above setup allows 45° per division but if more a c -
curacy is required the S W E E P T I M E / D I V setting may be
changed and magnified without touching the A V A R I A B L E
control and if necessary the trigger level can be readjusted.
For this type of operation, the relationship of one division
to 45° no longer holds. Phase difference is defined by the
formula a s follow.
A P P L I C A T I O N
P h a s e difference
Phase difference = horizontal distance of n e w s w e e p range
(div) x 4 5 ° / d i v
New S W E E P T I M E / D I V setting
Original S W E E P T I M E / D I V setting
Another simple method of obtaining more a c c u r a c y quick-
ly is to simply use " x 1 0 M A G " for a scale of 4 5 ° / d i v
One c y c l e adjusted t o o c c u p y 8 div.
- P h a s e difference
Expanded s w e e p w a v e f o r m display.
Fig. 2 0
RELATIVE MEASUREMENTS
If the frequency and amplitude of some reference signal
are known, an unknown signal may be measured for level
and frequency without use of the V O L T S / D I V or S W E E P
T I M E / D I V controls for calibration.
T h e measurement is made in units relative to the reference
signal.
* Vertical Sensitivity
Setting the relative vertical sensitivity using a
signal.
1. Apply the reference signal to INPUT jack and adjust the
display for a normal w a v e f o r m display.
Adjust the V O L T S / D I V and V A R I A B L E controls s o that
the signal coincides with the C R T face's
lines. After adjusting, be sure not to disturb the setting
of the V A R I A B L E control.
Phase difference
reference
graduation
2 3