My Brand New CTC-7!

[Electronic M]

I've got that on a couple of sets....One has a green/blue-green dot where a blue one should be.....Very noticeable on a VCR blue screen.

[old_tv_nut]

No way you can cause a single phosphor dot to disappear. This is a manufacturing defect. Normal to have a small number of these. The maker would have a QC spec saying where on the screen they could appear, and how many, before it was considered a reject. For example, they might define a center circle where none were allowed, a larger radius allowing a certain number, and then the remaining area with a larger number allowed, plus perhaps an over-all total maximum. Don't recall if these numbers typically show in the published specs; they might be published for a professional monitor though not for the tube itself.

[SwizzyMan]

Originally Posted by old_tv_nut

No way you can cause a single phosphor dot to disappear. This is a manufacturing defect. Normal to have a small number of these. The maker would have a QC spec saying where on the screen they could appear, and how many, before it was considered a reject. For example, they might define a center circle where none were allowed, a larger radius allowing a certain number, and then the remaining area with a larger number allowed, plus perhaps an over-all total maximum. Don't recall if these numbers typically show in the published specs; they might be published for a professional monitor though not for the tube itself.

That is pretty cool right there! There are about maybe 5 of these and they are away from the center of screen. Must have barely passed QC!

[Tom9589]

It was the same situation when computer hard drives first came out. There were always some bad sectors, but they were mapped out and the hard drive controller would not try to write to the bad sectors. Today, I doubt that there are any bad sectors on hard drives.

[SwizzyMan]

Anyone have any original advertising literature with my pensbury featured in it? I'd love to find one.

[BigDavesTV]

Dave - Id take this any day over what happened to my RCA Hi-Lite 21FBP22 - neck just neatly sheared itself and went to air right where the blue lateral spring rests

Ugh...that really stinks. Was that tube a rebuilt, or one that had been in service and suddenly broke? I have not seen that happen yet, but I'm always careful about not making yoke and purity clamps too tight, and I have wondered about the tension on the blue lateral magnet, more than once.

[David Roper]

She'd probably be less surprised the set was living again than that she was.

[SwizzyMan]

Originally Posted by David Roper

She'd probably be less surprised the set was living again than that she was.

You're probably right...

[SwizzyMan]

Turned the set on today after a month or two of sitting dormant. There is a complete absence of red. Red gun checks brilliant red screen and background react as normal. It is just that I have no red in the color spectrum. What could be the cause of this?

Resolved. X Demod tube had a burned out filament.

[old_coot88]

That's an example of why restored sets are always a "work in progress".

[stromberg6]

Hi, Very glad to know it was only a 12AZ7 gone bad. Just a little hint about color loss or intermittent, but only for the early production chassis with wax caps: wax dripping on the -Y output sockets can cause loss of color(s). Cleaned up the socket, and put in Orange Drops. Problem solved!
Kevin