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


Jim Ford
 

I've been following this thread with some interest because I have a 7B71 myself.  Planning to try it in 7904 when I get a chance.  With 7A26 and new-to-me 7A11's.  Maybe this weekend.  I will post my results. Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Raymond Domp Frank <hewpatek@gmail.com> Date: 4/17/19 7:43 AM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] 7B71 time base jittering at 50ns/div, but not other speeds. On Wed, Apr 17, 2019 at 03:46 PM, John Griessen wrote:>> 20 ns is usually solid>You seem to say that it too sometimes displays the same behaviour, which is only natural, as may be deduced from what I wrote earlier.You are looking at a very slow ramp/edge, triggering a time base at about its top speed at almost top amplitude level with a vertical sensitivity of only 2 mV / div.Such a slow ramp provides very little information in your measurement setup. It may be an interesting experiment.It is possible that some imperfect/varying contact causes the effective trigger voltage to vary by a few 100 microvolts, which would cause the behaviour that you see. If you'd see the same effect with a steeper slope with a larger amplitude at the same time base speeds, *that* would mean something and would point specifically to a problem in the time base.Raymond

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