While Dave dissects their bodies, I seem to have taste for their brain contents
This puppy's brains are now properly torn apart and splattered across some graphs. Initially just wanted to check if there is risetime difference <=200mV/div & >=500mV/div. Kink there is in graph. But noticed that Sin(x)/x causes noticeable overshoot.
Teaser image from PDF:Did risetime test across vertical setting ranges in 1GSa/s and 250MSa/s Sin(x)/x ON/OFF modes.OFF mode looked a bit more logical than wavy CGI in ON mode.
So I did the second test using Testec TT-DE 112 950MHz demodulator probe as scalpel.20, 40, 60, 80, 100, 120MHz sine.
350mVpp and 3500mVpp signal levels.
1GSa/s Sinxx=ON; 250MSa/s Sinxx=ON; 250MSa/s Sinxx=OFF
- Looked at gen output after test cable & 50ohm pass-thru using demod and Agilent U1272A. No level dropoff with rising freq, gen is good then.
- Did run first testset (1GSa/s) with demodulator and scope after pass-thru. Level dropoff detected with rising freq just like it should be over scope input.
- Compared if demodulator affected scope readings - near zero effect.
- Did run all testsets (3x2x6) w/o demodulator, recorded voltages and risetimes.
Adjusted demod amplitudes to start of each testset 20MHz reading in Excel.
Graphed demod voltages with scope voltages.
Teaser image from PDF:Noticed:
- Sinxx has heavy effect on risetime only when looking at step response, not when looking at stable sine.
- 50mV/div and 500mV/div have so large relative voltage differences with Sinxx=ON that seem to belong to different scopes. 500mV/div overshoots big time when looking at normalized graphs.
- With Sinxx=OFF normalized response graphs are almost identical.
Conclusion:
Everything happening with Sinxx on just pure CGI. Probably Sinxx=OFF is not a filter, but (more closer to) true response that gets hack-o-boosted big time. How else to explain massive sine Vpp overshoot, especially in 250MSa/s case?
Think I had my way with this thing now. Maybe should cook it instead of christmas turkey