[ARC5] Oscope Question

[Tom Lee]

What model scope do you have? CRTs of other than the most basic (e.g., 
Heathkit/Eico) scopes have additional structures whose potentials affect 
geometry beyond focus and astigmatism. Pincushion or barrel distortion 
can result from misadjustment. If you're seeing a similar effect at 
other corners, this seems more likely.

If the bend changes as you alter the sweep speed, then that's not it. In 
that case, see if the effect is synchronous with line freq (set the 
power line as your trigger source). If it is, then you have ripple on 
the plate driver.

--Cheers,
Tom

-- 
Prof. Thomas H. Lee
Allen Bldg., CIS-205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu
650-725-3383 fax

On 1/19/2017 4:32 PM, Robert Eleazer wrote:
> I have noticed something interesting with an oscilloscope I have.  
> With no signal input, down at the lower right hand corner the trace 
> takes a downward dip, and if you adjust the vertical position of the 
> trace still lower the trace bends up a bit and kind of resembles an 
> S-curve at the end.
> Any of y'all have any idea what this might be?  The scope works fine 
> otherwise.
> Thanks,
> Wayne
> WB5WSV
>
>
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