Re: 2445A calibration

 

On Sat, Oct 13, 2018 at 02:13 PM, <maxim.vlasov@...> wrote:


I can observe that when 1 MOhm input on the scope is selected, the square
waveform signal delivered by the BNC cable has a visible overshoot on the
rising edge. So, likely the C105 & C205 have to be adjusted too.
That is only natural with that setup, i.e. a basically open-ended 50 Ohm cable driving the 1 MOhm input with a signal having higher-frequency content.
Adjusting the input capacitance (often resulting in *de*normalizing) won't help and will be counterproductive. The input capacitance very rarely needs adjustment over a 'scope's lifetime. Readjusting basically is done only to make sure both channels are equal so you can swap probes between channels and sometimes between 'scopes.

Raymond

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