Re: A possibly sick 7904A


 

Typically you need a faster repetition rate on your test signal for it to be bright at 500pS/div.

I'm guessing that you were using a fast rise pulse from a CG551AP or CG5001 or PG506 for calibration. If so this has a pretty low repetition rate compared to the time for a sweep at 500pS/div so it will be dim.

HtH
David

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