Tektronix RSA6100A Technical Reference page 79

RSA6100A Series Technical Reference
d. Set input attenuation for manual control.
Select the Ampl softkey.
Deselect the Auto radio button.
The attenuator now can be manually controlled.
Set Internal Attenuator to 20 dB.
e. Press Run.
f. Check for an RF ADC overrange message at the bottom edge of the
display.
g. If the overrange message does not appear, reduce the internal attenuation
by 5 dB and go to step e above. Continue to step h if the overrange
message appears or if attenuation is 0 dB.
NOTE.
Overrange errors typically occur at Attenuation = 10 dB in this step.
h. If the overrange message does appear, then add 5 dB of internal
attenuation and continue. For example, if the overrange error happens
when attenuation is set to 10 dB, then set the attenuation to 15 dB.
i. Press Run.
j. Read the noise amplitude on Marker M1, in dBm/Hz.
k. Subtract the value of MR obtained in step 13 to obtain the phase noise
amplitude at +990 kHz.
For example, if MR = 4.7 dBm and M1 = –129.6 dBm/Hz, then M1-MR =
–134.3 dBc/Hz.
l. Enter the value obtained at 990 KHz in the test record for phase noise at
1 MHz.
NOTE. Note that the phase noise at 990 kHz is slightly greater than at 1 MHz,
but does not include power from narrow-band spurs that tend to reside at
even MHz intervals.
15. Obtain the phase noise at 6 MHz offset. Start by setting the RSA6100A to the
settings listed below:
a. Center Frequency: 1005.99 MHz.
b. Span: 10 kHz.
c. Center Markers in the middle of the screen.
Performance Verification
63