Datasheet

Performance Verification
adjusted trigg
er level from the FCA/MCA3X00 Series instrument into the test
record as 1X Trigger Level Uncertainty at 0 V.
15. On the Functio
n Generator, reduce the signal output level until the Tektronix
FCA/MCA3X00 Series instrument does not trigger (the Trig LED stops
flashing). Then slowly increase the Function Generator output to find the
minimum amplitude to cause the unit to count. This does not have to be an
accurate count, you are just finding the point the counter just starts to trigger,
on noise. Enter the Function Generator amplitude in the test report as 1X
Just Trigg
ers.
16. On the Tektronix FCA/MCA3X00 Series instrument, push the Input A button
and set th
e input attenuation to 10X.
17. Disconnect the cable and attenuator stack from the Tektronix FCA/MCA3X00
Series i
nstrument, remove one of the external 10X Attenuators, and reconnect
the cable and remaining attenuator to the Tektronix FCA/MCA3X00 Series
instrument.
NOTE. As you go through this procedure you will be told to remove or add
an attenuator from/to the attenuator stack. Always remove/replace the same
attenuator when you do this.
18. Repeat Steps 12 through 15, and enter the values in the test report as 10X
Trigger Level Uncertainty and Just Triggers (10X).
19. Push the Input A buttontoreturntotheNumericalAnalysisscreen(shows
Std).
20. Set the Function Generator signal amplitude to 3.0 Vpp.
21. Slowly decrease the Function Generator amplitude until the counter accuracy
is affected; that is, when the Std Deviation at least doubles (watch for a
sudden shift from mHz to Hz, as well as watching the numbers), o r when the
f
requency readout becomes noticeably incorrect. You should wait for two or
three sample periods after changing the amplitude before taking the reading.
Enter the results in the test report as 10X Just Becomes Inaccurate .
NOTE. When adjusting the signal amplitude, if y ou hear a relay click in the
generator there will be a few cycles of incorrect data, which must be ignored.
Wait se veral seconds before proceeding.
22. Disconnect the cable to the Tektronix FCA/MCA3X00 Series instrument,
replace the external 10X Attenuator removed in Step 17, and reconnect the
cable to the Tektronix FCA/MCA3X00 Series instrument.
2–14 FCA3000, FCA3100, and MCA3000 Series Specifications and Performance Verification