CFG253
Performance Verification & Adjustment Procedures
Page 7 of 19
Procedure #: CP1005 Revision: A
4.
Check Square Wave Duty Cycles
a.
Set-Up:
AMPLITUDE
Midrange
RANGE
1K
FUNCTION
Square Wave
FREQ/10
Button In
FREQ DIAL
3.0
b.
Test Scope Set-Up:
Volts/Div
1V
AC/GND/DC
DC
Time/Div
0.2 mSec
Trig Slope
+
c.
Connect MAIN OUTPUT to test scope vertical input via coax cable and 50 ohm
terminator. Adjust Trig Level as necessary for a stable display.
d.
Use test scope variable Time/Div control to set the display for 1 complete cycle
over 10 divisions.
e.
Check for nearly equal positive and negative half cycles (50 % duty cycle).
Readjust the variable Time/Div as necessary to maintain 1 complete cycle over
10 divisions.
f.
Set FREQ/10 button out.
g.
Check that the frequency increases by a factor of 10 as shown by a display of
approximately 1 cycle per division on the test scope.
h.
Set the FREQ/10 button in. Rotate the SYMMETRY knob CCW and use the
Time/Div variable to set the first half cycle to 1 division. Rotate the SYMMETRY
knob CW and check for the same half cycle to increase to 5 divisions or greater (a
duty cycle change of 5:1).
i.
Return the SYMMETRY knob to the center detent position and the test scope
Time/Div variable to the detent position.
