Hi Jouko,
Rise times add approximately in root-sum-squared fashion (square each rise time, sum them, then take the square-root of the result). So if you have a 2ns rise time amplifier in cascade with another 2ns rise time amplifier, the combination will have a 2.8ns rise time or thereabouts.
-- Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
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On 2/22/2021 08:37, Jouko Koskinen wrote:
Hello,
I tried by swapping one Q150 from working unit. That brought input signal to screen.
I acquired two Q150 as both channels were similar and showed only 340k input resistance.
Those are now in place and partial calibration (not HF compensation) is done. The unit seems to be working.
Rise time is roughly 3ns in 7603 frame (Leo Bodnar pulser). The frame itself with 067-0587-01 calibration fixture showed 2ns rise time.
Does that sound logical?
Fortunately I didn't have to take the cleaning challenge...
Regards,
Jouko
