Fluke 5820A, Operator'S Manual

Page: 81 / 272

Front Panel Operation
Calibrating the Pulse and Frequency Response on an Oscilloscope
4
4-23
4-36. Oscilloscope Frequency Response Calibration Procedure
Perform this sample procedure, which verifies the frequency response on your
oscilloscope, after the pulse response verification.
This procedure checks the bandwidth by finding the frequency at the -3 dB point for your
oscilloscope. The reference sine wave in this procedure has an amplitude of 6 divisions,
so that the -3 dB point can be found when the amplitude drops to 4.2 divisions.
Before you start this example procedure, verify that you are in Level Sine mode. If you
are, the Control Display shows the following menu:
FREQ CHG
jump
RATE
1 MHz
MORE
OPTIONS
SET TO
LAST F MODE
levsine
f f f f f
Perform the following sample procedure to calibrate the frequency response:
1.
Reconnect the signal by pressing
l
on the Calibrator. Select 50
Ω
impedance or
use a 50
Ω
external termination directly at the oscilloscope input.
2. Adjust the sine wave settings in the Output Display according to the calibration
recommendations in your oscilloscope manual. For example, for the HP 54522C
oscilloscope, start at 600 mV @ 1 MHz. To enter 600 mV, press
S MMÅs
; then press
b
.
3. Adjust the oscilloscope as necessary. The sine wave should appear at exactly six
divisions, peak-to-peak, as shown below.
If necessary, make small adjustments to the voltage amplitude until the wave reaches
exactly six divisions. To fine-tune the voltage, press
É
to bring a cursor into the
Output Display, move the cursor with the
i
key, and turn the rotary knob to
adjust the value. (See “Adjusting Values with the Rotary Knob” earlier in this
chapter.)
oq016f.bmp