User Manual

Performance Ver
ification
This level must be w ithin 17 dB of the level that you r ecorded in step 3. For example, if the reference level from step 3 is
9 dBm, and the le
vel that you measured in this step is -7 dBm, then the difference between the two measurements is 16
dBm, which is within the probe specification.
11. Set the probe to the 42 V range (÷ 50).
12. Change the reference level of the spectrum analyzer to -24 dBm.
13. Record the level displayed on the spectrum analyzer. This level must be within 37 dB of the level that you recorded in
step 3. For example, if the reference level from step 3 is 9 dBm, and the level that you measured in this step is -26 dBm,
then the difference between the two measurem ents is 35 dBm, which is within the probe specification.
14. K eep the setup for the next procedure (CMRR).
CMRR (Common Mode Rejection Ratio)
Verification
Use the setup from the previous test, and enter your measurements in the table below to ca lculate the CMRR. Record the
calculated CMRR in the test record.
1. Se t the probe to the 42 V range (÷ 50).
2. Connect the probe to the DM pins of the BNC-to-probe tip adapter.
3. Set the synthesizer for 1 MHz and 10 dBm.
4. Ad just the spectrum analyzer input attenuator to accept the high level of 10 dBm.
5. Se t the reference level to 0 dBm, the center frequency to 1 MHz, and the vertical scale to 10 dB/div.
6. Ad just the span to 10 kHz and the resolution bandwidth to auto.
7. Record the level displayed on the spectrum analyzer. This represents the differential mode measurement at the 42 V
range (÷50).
8. Record the level displayed on the spectrum analyzer. This represents the differential mode measurement at the 42 V
range (÷ 50).
9. Connect the probe to the CM and ground pins on the BNC-to-probe tip adapter.
10. A djust the reference level of the spectrum analyzer to display the waveform. Use the noise filter for easier measuring.
11. Record the level displayed on the spectrum analyzer. This represents the common mode measurement at the 42 V
range (÷ 50).
12. Calculate the CMRR for each voltage range by subtracting the common mode measurement from the differential
mode measurement.
13. Repeat the procedure for the remaining frequencies listed in the table below.
Test frequency
Differential mode
measurements Common mode measurem ents CMRR @42 V (Calculated)
42 V 42 V
30 kHz
1MHz
250 MHz
P6250 & P6251 Technical Reference 41