Sylvania Superset Update

[JohnCT]

Originally Posted by TrllVl90

Hey,

Okay, the SAMS lists the filament voltage at 22V.

As for the softness of the image, I did knock the convergence rings out of place with my arms while I was cleaning dust out of the cabinet (accidentally, of course). I haven't tried realigning them yet. The picture was much sharper before then, smearing aside.

It's not 22V, it's 6.3VAC on that tube. I literally worked on a thousand of them. Sams misprint I suppose.

The flaring in your picture is not a convergence issue. Misconvergence will show as a clearly defined border of color, not a general lazy flaring off the picture on brighter images.

Hopefully, your HV is low, which can happen if the retrace capacitor is too high in value compared to the original (it must be an *exact* value - no upping by 10-20% like other caps allow). If the HV is low, your filament will be low and will cause that general flare off the bright on-screen objects.

As tubes get older, they become more sensitive to filament voltage than when they'r new. Most CRT testers of the time had a "life" test. Pushing the "life test" button would reduce the filament voltage a few tenths up to a half of a volt. A strong tube would barely lose emission but a weak tube would drop into the "yellow" or "red" area.

Ordinarily, a flare like that is a soft tube, but since you changed the retrace cap which has a big effect on the HV (and therefore filament), checking the filament voltage at this stage is the best thing to do.

If the voltage is 6.3 (not 6.1!) with a TRMS meter, your tube is soft and your repair was fine. If the filament is low, revisit your retrace cap change and double check the value.

John