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Old 26th Jun 2013, 8:58 pm   #18
John_BS
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Join Date: Dec 2008
Location: Wincanton, Somerset, UK.
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Default Re: Tektronix 465B Scope - Some problems.

Dave:

As you have a second 'scope,. you might get a better handle on where the problem arises by switching off the sweep and centering the beam (as you have in one of your photos), then check for signals (relative to ground) on both Y and X plates individually. If there's no "noise" on the deflection plates, you're left with possible EHT and collimation issues. Oh, and check it's not some kind of mains-related problem by setting the scope trigger to "Line" and having a look at 50mS/div.

PS: I assume the screening cover is in place over the EHT section?

John
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