
Chapter 4: Testing Performance
Analog Bandwidth - Maximum Frequency Check
70
11
Change the generator frequency to the maximum value for the model being tested as shown
in the table below. It is not necessary to adjust the signal amplitude at this point in the procedure.
12 Change the scope time base to the value for the model under test in the table above.
13 Measure the input power to the scope channel at the maximum frequency and convert this
measurement to Volts RMS using the expression:
For example, if the power meter reading is 4.0 W, then Vin = (4.0*10
-6
* 50)
1/2
= 14.1 mVrms.
Record the RMS voltage in the Analog Bandwidth - Maximum Frequency Check section of the
Performance Test Record (Vin @ Max Freq).
14
Press the Clear Display key on the scope and record the scope V rms reading in the Analog
Bandwidth - Maximum Frequency Check section of the Performance Test Record (Vout @
Max Freq).
15 Calculate the gain at the maximum frequency using the expression:
For example, if (Vout @ Max Frequency) = 13.825 mV, (Vin @ Max Frequency) = 13.461 mV and
Gain @ 50MHz = 1.0023, then:
Record this value in the Calculated Gain @Max Freq column in the Analog Bandwidth - Maximum
Frequency Check section of the Performance Test Record. To pass this test, this value must be greater
than -3.0 dB.
Setting Model
DSO/MSO9404
A
DSO/MSO9254
A
DSO/MSO9104A DSO/MSO9064A
Maximum Frequency 4 GHz 2.5 GHz 1 GHz 600 MHz
Scope Time Base
Setting
100 ps/div 100 ps/div 100 ps/div 100 ps/div
Click here and enter
time base value from
Gain
Max Freq
20 log
10
V
out Max Freq
V
in Max Freq
Gain
50 MHz
------------------------------------------------------------------------------=
Gain
Max Freq
20 log
10
13.825 mV 13.461 mV
1.0023
------------------------------------------------------------- 0.212 dB==
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