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  #16  
Old 01-29-2017, 07:55 PM
old_coot88 old_coot88 is offline
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Originally Posted by vts1134 View Post
Well, the audio problem is back. Here is a quick video showing the problem. The area that you see in the video is around the tone control. It's the darndest thing . I'm thinking something has an intermittent connection to ground?
I've seen those old paper tubular caps develop intermittents internally where the lead joins the foil.
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  #17  
Old 01-30-2017, 07:49 AM
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Originally Posted by old_coot88 View Post
I've seen those old paper tubular caps develop intermittents internally where the lead joins the foil.
Sorry, I should have mentioned that all of the paper and electrolytic capacitors in the set have been replaced. They are inside the old shells...it only looks original .
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  #18  
Old 02-05-2017, 07:57 PM
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Decided to take a bit of a break tonight and enjoy the set.

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  #19  
Old 02-05-2017, 08:03 PM
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Nice!
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  #20  
Old 02-05-2017, 09:36 PM
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Yes, the Superb owl... First one to go into overtime.
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  #21  
Old 02-06-2017, 05:05 PM
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Yes, the Superb owl... First one to go into overtime.
And I went into overtime... ah, I mean I went to bed.

I was surprised this morning...
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  #22  
Old 02-06-2017, 08:34 PM
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I thought I'd update my problems list.


1- Raster is off center to the left.
Still working on this one

2- There appears to be a slight ripple present in the vertical.
SOLVED! There was a power cord close to the base of the CRT.

3- There are three extremely faint vertical bars on the left side of the picture.
Still working on this. I'm going to focus on this next. I'm going to hook up my video generator to the set to test whether the problem is in the video inverter I built or the set.

4- The picture focuses well in the center, but not at the edges.
Still working on this. I like Ben's suggestion that it could be the crt itself. I have another 10FP4 that I'll swap in the set to see if it's any different.

5- The horizontal linearity isn't great.
SOLVED! This was also caused by the power cord's proximity to the crt base.

6- The vertical deflection is collapsed on startup (although tonight it didn't happen)
I'm going to call this one SOLVED! I resoldered pins on the vertical oscillator and slightly moved one of the capacitors on that tube and the problem has not returned the past 5-10 times I've turned the set on.

7- There is a slight buzz in the audio (only audible when no audio is present)
This problem is still happening, but I might just be too picky.

8-There is a loud crackle sound sporadically coming from the speaker.
SOLVED! Cleaning the tube base on the audio output tube cleared this up.
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  #23  
Old 02-16-2017, 08:20 PM
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Update:

The vertical collapse is back. I'll have to continue to troubleshoot.

I have wired in the video amplifier circuit into the set in a way that could be taken back out without any sign it was there. I added two terminal strips to the set using existing bolts and nuts. I was able to jump a resistor across the existing picture control to use it in the set as it was intended.



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  #24  
Old 02-16-2017, 08:24 PM
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I swapped another 10FP4 into the set and although it is dimmer than the 1st, the focus is better. The picture is quiet nice as is, but not yet perfect so on we go.



Here is the video inverter/amplifier I ended up with.

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  #25  
Old 02-16-2017, 08:28 PM
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I'm hoping for some help with the vertical bars on the left of the screen. The photo below shows them clearly. This anomaly doesn't go away when I remove the video amplifier circuit. Does anyone have any ideas ?

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  #26  
Old 02-16-2017, 10:27 PM
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They look to be drive bars. A ringing in the horizontal circuit that usually changes screen brightness by modulating the scan speed. You may be able to kill it with the horizontal drive control (width and linearity settings may also effect it). On some sets it is baked into the design or the aging of unobtainium parts.
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  #27  
Old 02-17-2017, 02:04 AM
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I dunno if you're trying to save all the original parts as possible, you want to hone your troubleshooting skills, or you're just a masochist, but all those old capacitors are ultimately just a multitude of tiny unknown variables.

Just sayin' :/
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  #28  
Old 02-17-2017, 06:59 AM
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Quote:
Originally Posted by MadMan View Post
I dunno if you're trying to save all the original parts as possible, you want to hone your troubleshooting skills, or you're just a masochist, but all those old capacitors are ultimately just a multitude of tiny unknown variables.

Just sayin' :/
I'll take that as a very nice compliment. All of those capacitors are retuffed original shells. Since this is the second time that's been mentioned, I trust my method for restuffing is such that most can't tell that I've done anything (which is half of the goal in a restoration). The only modern capacitors that are visible in the set are the ones associated with the video amplifier/inverter that I added. I figured since that is a modern addition then it should have visible modern capacitors.
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Last edited by vts1134; 02-17-2017 at 07:06 AM.
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  #29  
Old 02-17-2017, 07:05 AM
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Quote:
Originally Posted by Electronic M View Post
They look to be drive bars. A ringing in the horizontal circuit that usually changes screen brightness by modulating the scan speed. You may be able to kill it with the horizontal drive control (width and linearity settings may also effect it). On some sets it is baked into the design or the aging of unobtainium parts.
There is no horizontal drive control on this set . On other sets I've worked on that include a horizontal drive control, adjusting it would effect a single bright white vertical line on the left side of the screen. I've not seen multiple dark lines like this before. What unobtainuim parts might create this effect? Are there troubleshooting step I can try to hone in on the source of the problem? I do have an entire spare chassis for this set from which I can borrow parts.
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  #30  
Old 02-17-2017, 08:19 AM
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Transformers/chokes/yokes in the circuit.
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