Keysight Infiniium MSOS804A - Setting Up Triggers

Testing Performance 3
S-Series Oscilloscopes Service Guide 39
12 Change the oscilloscope horizontal scale to the value for the model under test
in the preceding table.
13 Measure the input power to the oscilloscope 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 μW, then Vin = (4.0*10
-6
*
50Ω)
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 [Clear Display] on the oscilloscope 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.
16 Change the scope setup as follows:
a Change the channel vertical scale to 10 mV/div.
b Reset the horizontal scale to 16 ns/div (to display 8 cycles of a 50 MHz
waveform).
17 Change the generator output as follows:
a Reset the generator frequency to 50 MHz.
b Change the amplitude to the value suggested for this scale setting in the
Nominal Generator Amplitude Settings table.
18 Repeat steps 8, 9, and 10 to measure the reference gain at 50 MHz for this
scale.
19 Repeat steps 11 through 15 to measure the gain at maximum frequency for this
scale setting.
20 Repeat steps 15 through 19 to complete measuring gains for remaining scale
settings for channel 1 in the Analog Bandwidth—Maximum Frequency Check
section of the Performance Test Record.
V
in
P
meas
50Ω×=
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==