Fluke 5820A, Operator'S Manual

Page: 82 / 272

5820A
Operators Manual
4-24
4. Increase the frequency to 400 MHz (for 500-MHz instruments), or 500 MHz (for
600-MHz instruments). To enter 400 MHz, press
QMMje
; then
press
b
.
5. Continue to increase the frequency slowly until the waveform decreases to 4.2
divisions, as shown below.
To increase the frequency slowly, fine-tune it using the rotary knob. To do this, press
É
to place a cursor in the Output Display. Press
É
again to place it in the
frequency field, and use the
i
and
t
keys to move it to the digit you want to
change. Then change the value by turning the rotary knob. Continue making small
increments in the frequency until the signal drops to 4.2 divisions. At 4.2 divisions,
the signal is at the frequency that corresponds to the -3 dB point.
oq017f.bmp
6. Remove the input signal by pressing
l
.
7. Repeat this procedure for the remaining channels on your oscilloscope.
4-37. Calibrating the Time Base of an Oscilloscope
Calibrate the horizontal deflection (time base) of an oscilloscope using a method similar
to the vertical gain calibration. The Calibrator generates a time marker signal and the
signal’s peaks are matched to the graticule line divisions on the oscilloscope.