Re: 7B71 time base jittering at 50ns/div, but not other speeds.


John Griessen
 

On 4/17/19 4:53 AM, Raymond Domp Frank wrote:
The jitter is constant at all trigger levels on 50ns/div, but not other
speeds.
With "not at other speeds" you mean not at faster speeds either?
Yes, of the four fastest speeds, 50ns/div is always jittery +/- 1/2 div.
20 ns is usually solid, with maybe 1/2 trace width jitter.
100ns/div and 200ns/div randomly can have excess jitter.

These show this symptom:

https://www.ecosensory.com/tek/tek-7B71_trouble-6.jpg OK (100ns/div)
https://www.ecosensory.com/tek/tek-7B71_trouble-7.jpg random (50ns/div)
https://www.ecosensory.com/tek/tek-7B71_trouble-8.jpg good (20ns/div)

A 7B70 does not do this, has maybe 1/2 trace width jitter up to fastest, (for it), 20 ns/div
7B10, 7B15, 7B92A do not do this either.

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