Grid - Screen Alignment (X-Rays) - diyAudio
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Old 30th September 2008, 12:58 AM   #1
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Default Grid - Screen Alignment (X-Rays)

I recently promised someone I'd xray the Chinese 6L6CGR I had.
Don't remember now which thread? Might as well start another...
There are no holes "for screen alignment" in plate of this tube.
Don't know if that is really what typical beam power plate holes
are for, or something else?
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Old 30th September 2008, 01:00 AM   #2
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Pic 2
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Old 30th September 2008, 01:02 AM   #3
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Pic 3

This tube is just slightly too big to fit all in one Xray image.
But I have one coming that tries to cover most of it.
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Old 30th September 2008, 01:05 AM   #4
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Mind you, both getters were in the bottom. These wings are for G1.
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Old 30th September 2008, 01:07 AM   #5
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Extreme closeup of alignment (or mis-alignment?) near the center.
I have no reason to think there is anything especially wrong here.
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Old 30th September 2008, 01:43 AM   #6
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Wow,Cool pics!
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Old 30th September 2008, 02:28 AM   #7
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On the right side of the third image, it looks like parallax effect reaches a minimum and the grid-screen offset is about 20% of the winding pitch. Could probably be better...

Thanks for the x-rays!

Tim
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Old 30th September 2008, 03:01 AM   #8
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Bah, I was just about to edit then it said it timed out...


Edit: here's the image, brightened up a bit (for analyzing relative density, refer to the original) and with a scale marker (based on the bulb being about 1.5" across). Evidently the grid pitch is about 14 TPI, so the misalignment is around 0.014".

Tim
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Old 30th September 2008, 05:07 AM   #9
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*cough*

Click the image to open in full size.
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Old 30th September 2008, 08:42 AM   #10
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The total diameter across the entire glass envelope,
which also happens to be the same diameter as the
octal base, is only 1.3 inches. Rather small for a 6L6.

Dunno what breed of monster you thought this was?
I think you might have diameter mixed up with radius.
There is simply no way this tube is 3 inches across...

Its probably too late to edit your post now, but you
seem to be hosting the picture elsewhere. I would
assume you still have access to edit the scale?

How does this affect your calculation regarding the
pitch of the grids?
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