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  #16  
Old 02-04-2013, 10:40 PM
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bandersen bandersen is offline
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You got me worried so I just doubled checked mine by disconnecting one lead from everything else. It measures good at about 36 ohms.
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  #17  
Old 02-05-2013, 12:31 AM
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I junked a 630 chassis, I'll see if I have the trap from it tomorrow.
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  #18  
Old 02-05-2013, 06:52 AM
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Thanks Eric.
I disassembled the trap this morning and found that the smaller of the two coils is still intact and reads 3ohms. The break is in the larger coil.
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  #19  
Old 02-05-2013, 09:35 AM
old_coot88 old_coot88 is offline
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How is the focus range now while using the pm trap?
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  #20  
Old 02-05-2013, 10:22 AM
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vts1134 vts1134 is offline
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For those who don't know I was trouble shooting my focus control in relation brightness issue with Bill in some private messages.

Quote:
Originally Posted by old_coot88 View Post
How is the focus range now while using the pm trap?
I'll check on it tonight and let you know. Even though I was 70 ohms low on my bleeder resistor which would have increased current flow, half of that was made back up do to my ion trap being open. I should have read 56 ohms across the trap instead of the normal 21.913 ohms with a good ion trap making me only 34 ohms low on the entire circuit (assuming all other components are on spec).
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  #21  
Old 02-06-2013, 06:23 PM
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The focus is good with the pm trap. I have to turn the focus coil to a strange angle because the trap is pulling the beam in a different angle. I think once I get a replacement electromagnetic trap I'll be in business.
Any one out there have a spare?
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  #22  
Old 02-06-2013, 08:24 PM
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I looked in my garage but didn't find one, I keep forgetting to check at work where I have some of the parts stashed.
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  #23  
Old 02-06-2013, 08:25 PM
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I wonder if it's possible to rewind the open coil? If it's just wound straight across the core it might not be too hard.

Which one is open, the large or small coil?
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  #24  
Old 02-06-2013, 08:38 PM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by vts1134 View Post
The focus is good with the pm trap. I have to turn the focus coil to a strange angle because the trap is pulling the beam in a different angle. I think once I get a replacement electromagnetic trap I'll be in business.
What happens if you flip it around?
Are you using the pm unit with the EM one still in place? If so, residual magnetism in it could be throwing things off a little.
Does the EM unit have solder lugs where the leads attach? If so, it is likely you can spot the break, because it'll usually occur right where the fine coil wire joins the lug.
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  #25  
Old 02-07-2013, 06:03 AM
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vts1134 vts1134 is offline
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What is the wire on the coil coated with? I found a break close to the end of the coil but I can't get continuity on the wire. I've tried melting it with fire and holding probe leads onto what looks like bare wire to me and it won't conduct. Is there something else I need to get off of the wire that can't be burned off? If I cant figure out how to expose the conductor in that wire and that point is the only break then I think I'll be able to repair the trap and be in business.
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  #26  
Old 02-07-2013, 09:37 AM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by vts1134 View Post
What is the wire on the coil coated with? I found a break close to the end of the coil but I can't get continuity on the wire. I've tried melting it with fire and holding probe leads onto what looks like bare wire to me and it won't conduct. Is there something else I need to get off of the wire that can't be burned off? If I cant figure out how to expose the conductor in that wire and that point is the only break then I think I'll be able to repair the trap and be in business.
It's coated with either laquer or enamel, probably laquer.

Do this. And bookmark this for future referance. No jive, it really works :

Lay an aspirin tablet (real aspirin, not Alleve, Tylenol ibupropin etc.) on the bench. Put the end of the wire on the tablet, and apply the tip of your soldering iron so the aspirin liquefies and engulfs the wire tip. It strips the wire clean as a whistle in a jiffy. It releases some nasty fumes though, so be sure there's some ventilation. The liquid acetylsalicylic acid is what does the stripping.

After some 60 years doing electrical stuff, i just learned this trick recently.

Last edited by old_coot88; 11-27-2014 at 08:48 PM.
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  #27  
Old 02-07-2013, 06:01 PM
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Melting asprin does the trick! I will keep this in my toolbox of tricks for sure. One thing to note if you want to try this method, "it releases some nasty fumes" is an understatement. It's pretty nasty stuff. It also leaves a coating on the wire itself, but you can just wipe that coating off. With the ion trap repaired and back in place we have a nice bright raster again! Now on to the next problem...the vertical section.
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  #28  
Old 02-07-2013, 06:40 PM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by vts1134 View Post
Melting asprin does the trick! I will keep this in my toolbox of tricks for sure. One thing to note if you want to try this method, "it releases some nasty fumes" is an understatement. It's pretty nasty stuff.
Yeah, it's a good idea to use a fan when you do it.
Quote:
It also leaves a coating on the wire itself, but you can just wipe that coating off.
When i sed "clean as a whistle" i should clarified that that's after you wipe the residue off to ensure there's no acid residue left. I would use a wet Q-tip.
Proponents of the aspirin trick state that it'll work on any size (laquered or enameled) wire, and that it's handiest for stripping the smallest gauges where mechanical scraping would likely break the wire. I imagine it'd also be useful for that ultra-flexible cable made of fine wire strands interwoven with polyester fibers, like some headphone cords.
Quote:
With the ion trap repaired and back in place we have a nice bright raster again! Now on to the next problem...the vertical section.
Yaay!

Last edited by old_coot88; 10-21-2015 at 09:35 PM. Reason: Typo.
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  #29  
Old 02-07-2013, 07:01 PM
Geist Geist is offline
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Hi All;
Vts1134, You with the help of many of the group, have made maybe slow, but significant progress.. I congratulate you on your progress..
THANK YOU Marty
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