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#136
02-15-2022, 03:32 PM
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I would of thought an electrostatic deflected CRT would be more susceptible to high voltage ripple vs magnetic field, although I get that one can be related to other.
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#137
02-15-2022, 04:02 PM
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It's very noticeable - especially the vertical stretching. It's like a bulge slowly moving up through the image.
Sure, if I'm just going to demonstrate this set, it's no big deal. At this point I'm more curious than anything and hoping to increase my troubleshooting skills.
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#138
02-15-2022, 04:45 PM
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OK, the little filament transformer definitely has an effect. If I unmount and move around it both effects the CRT image and hum coming out of the speaker. Will continue experimenting...
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#139
02-15-2022, 05:04 PM
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I've seen a lot of instruments which contain electrostatic deflected CRTS with MuMetal shields over the electron gun assembly. The typical deflection angle of an electrostatic CRT is very small compared to a magnetically deflected CRT so any stray magnetic field would have a more pronounced effect on an electrostatic CRT.
For a quick test, disconnect the tuner filament transformer and get a 6V lantern battery to power the tuner's filaments. See if the picture twerking and audio hum go away.
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#140
02-15-2022, 05:55 PM
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I added a shield from an Admiral 19A1 chassis. It had zero effect. I'll try to dig up a battery.
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#141
02-15-2022, 08:51 PM
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While experimenting with shielding the filament transformer and tuner tubes, the problem went away! No more vertical distortion and only minor horizontal.
I figure something, somewhere wasn't making good contact. It's not perfect, but I'll take it.   This pretty well sums it up. 
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#142
02-15-2022, 08:57 PM
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Aw man. Now we're not going to know what fixed it.
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#143
02-15-2022, 10:32 PM
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Yeah, and there's no reason to think it won't come back. Could be a chassis rivet not making good contact, a cold solder joint, intermittent tube short...
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#144
02-15-2022, 11:08 PM
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Time for some wiggling and tapping of things.
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#146
02-16-2022, 01:22 AM
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I eliminated it by redesigning the 1st audio amp.
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#147
02-16-2022, 05:53 AM
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It looks pretty good, considering it probably never played that good when it came from the factory. LOL.
__________________
RCA VICTOR and its dealers bring you......
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#148
02-16-2022, 08:03 AM
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Dang Dude! Seldom see linearity that good on electromagnetic-deflection sets.
Last edited by old_coot88; 02-16-2022 at 08:39 AM.
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#149
02-16-2022, 10:16 AM
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Not so fast
 Distortion problem is back and a new issue has cropped up. I used to get good focus in the middle of the control but now I need to have it full clockwise. The HV box is power in a rather odd way that makes me think the two problems are related.
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#150
02-16-2022, 11:19 AM
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You sure that's not Rosemary's Television you have there?!
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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Linear Mode
