Thanks Jon but I am not looking for accurate calibration.? After reading the manual a few times I see there are three adjustments for each channel.? So when I feel motivated I will look for them and try a tiny tweak to see what happens.
What I basocally want is for the -3 dB frequency to be above 300 MHz.? With three adjustments per channel I can see how I could get into a lot of trouble.? I don't want certified calibration so maybe I can boost the -3 dB frequency a little.? It's not terribly important.
Bob
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On Sunday, January 31, 2021, 02:23:28 PM PST, Jean-Paul <jonpaul@...> wrote:
Rebonjour, further musings.....
1/ We use? a leveled sine cal generator, eg Tek SG503,SG504 etc or HP 8640B to check BW.
2/ less is more... Eliminate cables if possible, the excellent Leo Bodnar 40 ps pulser has a BNC female to connect directly? to a 50ohm scope input.
3/ For 1 M ohm input scopes, Feedthru terms are not perfect, we have? some old ones or Chinese clone junk that are NOT good above 100 MHz, we recommend the Tektronix BNC 50 ohm feedthru, or the Mini-Circuits
4/ Tweaking transient response is an art not a science, use care, patience and compromise.
5/ like any amplifier, a scope vertical amp can have non-linearity.? The? response ( transients or BW) may change depending upon the trace positon on the screen.
Enjoy, and happy tweaking!
Amenities et cordialement,
Jon
