Re: 475 With a bowed display. . . .Ideas?

Chuck Harris


-Chuck Harris

Michael W. Lynch via wrote:


I went back and confirmed that the Geometry and Y Align controls were functioning correctly. Both circuits checked out good.

Reconfirmed all power supplies potentials and ripple.

Checked all physical connections to the CRT.

After that, the CRT needed to come out to see if steering magnets were used and had subsequently become dislodged (which was not the case).

Although I was holding out hope that physical damage to the CRT was not the cause, Chuck Harris hit the nail on the head with his first response to my inquiry.

Chuck Harris
Aug 8 #170283
Typically, when a proper application of the Geometry,
Focus, Astigmatism, Trace Rotation, and other affiliated
adjustments results in a screen that just doesn't look
as pretty as we would like, it means that there has been
an outside physical influence on the CRT (READ: OOPS! BANG!
$%^! & #!!*^! Why Me???)
Cause of Problem found, But problem not solved! After removing the CRT, I could detect the very faint "tinkle" of broken glass. Closer examination revealed that one of the the glass rods that supports for the Deflection plates and the geometry shield had been broken. this obviously skews the deflection plates and the geometry electrodes as well.

See the condition of the glass support rod in New photos at:

My next problem is that I do not have a replacement CRT. I was thinking (there I go again!) that I have one, but what I have available are a 154-0731-00 and a 154-0731-04 not the required 154-0677-10. So, I need to find a good CRT for this scope. This scope is too nice to just part out, but also worthless without a proper CRT.

Michael Lynch
Dardanelle, AR

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