Re: 11801 question
Hi Reg,toggle quoted messageShow quoted text
I did similar with a CSA803A. This scope has the slower Calibrator, about 120 ps rise time.
First I tested an SD-22 with the cal signal. 20 ps/div and 10 mV/div, which gives a reasonable steep mid part of the trace. About the 50% point centered at the grids center. During more than half an hour from startup I could not detect any shift in the trace.
Next I followed your splitter setup, with an SD-20 and an SD-26. In Enhanced Accuracy I set the SD-20 as delay reference and had the SD-26 delay calibrated to this. Displayed 20 ps/div and 5 mV/div. Made the mid region of the traces coincide by a small fine adjustment of Vertical Position of one of the traces. Again I saw no systematic shift of one trace w.r.t. the other. However there 2 occasions (which I noticed) where there was a short duration shift (more or less jumping) of one of the traces over 2-3 ps. That could jst as well be a shift vertically of course. I attributed this to a not firm enough cable connection somewhere since the trace returned nicely to the proper position. Not sure though.
Altogether I can't share your "pessimism" about the performance.
On Thu, Mar 28, 2019 at 12:52 AM, Reginald Beardsley wrote: