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  #16  
Old 03-20-2017, 05:17 PM
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How about that? Seems Zenith supplied these to Electrohome, and at least some were made by GE. I assume the one I took out is the original considering the date code.

Next up is a .047 microfarad cap under the chassis; it's a white one. It's connected parallel across the AC line after a pair of coils.
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File Type: jpg Original run capacitor.jpg (39.9 KB, 9 views)
File Type: jpg Flip side.jpg (44.1 KB, 8 views)
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  #17  
Old 03-21-2017, 06:40 AM
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An across-the-line cap ought to be replaced with an X2 safety cap, designed to fail open rather than short. Sal's and Just Radios have them, as well as other sources. X2 for across the line, Y2 for line to ground. There is also a cap rated X2Y2 for either use.

http://www.tuberadios.com/capacitors/

http://www.justradios.com/
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  #18  
Old 03-21-2017, 03:59 PM
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I forgot to mention, there's a 2-amp fuse in series with the circuit just before the white cap. Thanks though, I'll check that out.
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  #19  
Old 03-21-2017, 04:13 PM
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Quote:
Originally Posted by Reece View Post
An across-the-line cap ought to be replaced with an X2 safety cap, designed to fail open rather than short. Sal's and Just Radios have them, as well as other sources. X2 for across the line, Y2 for line to ground. There is also a cap rated X2Y2 for either use.

http://www.tuberadios.com/capacitors/

http://www.justradios.com/
These are AC rated non-polarized oil filled motor run caps. They are used for the resonant circuit of the VRT (voltage regulating power transformer)... Modern VRT isolation transformers spec out the same type of cap as 70's SS consoles like Jon's and Zenith CCII sets do.
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  #20  
Old 03-21-2017, 04:33 PM
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Nah, this is another cap, under the chassis:
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  #21  
Old 03-21-2017, 08:31 PM
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My bad, lost context.
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  #22  
Old 03-22-2017, 03:55 PM
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What's this particular white cap for though? All I know is that they should be replaced on sight. It's the only one in the set.

A couple of those coil leads look kind of toasty as well, wonder why.
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  #23  
Old 03-22-2017, 04:46 PM
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It basically shorts out any differential RF noise on the line. You could probably clip it out and not miss it...I've done that, but prefer to replace them so as to keep the original design.
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  #24  
Old 03-24-2017, 01:31 PM
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"Thanks! I ought to get a couple of spares eventually. If my 23GC45 has one - I haven't looked closely yet - that's probably going as well. Right now my Electrohome has a couple of vertical lines on the screen at all times. The Zenith gets one on the right that goes away after a few seconds."
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My 25GC45 has one, yours is the 23" version of the same chassis, so I'm sure yours does too. The value of the capacitor in those ferroresonant transformer is important, so you really need to get the right one.
It's not a standard motor-run capacitor value, the first place I looked for a replacement was electrical and HVAC supply websites. That TEDSS site is the only place I was able to find the correct part.

The cap in my set shorted out without warning after the set was on for a couple of hours. It'll pop the circuit breaker on the back when it shorts.
I replaced it with a cap I had from a parted out set, but who knows how long that one will last.

Last edited by wb2mep; 03-24-2017 at 01:35 PM. Reason: Forgot to quote post I was replying to
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  #25  
Old 03-24-2017, 01:49 PM
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Quote:
Originally Posted by wb2mep View Post
My 25GC45 has one, yours is the 23" version of the same chassis, so I'm sure yours does too. The value of the capacitor in those ferroresonant transformer is important, so you really need to get the right one.
It's not a standard motor-run capacitor value, the first place I looked for a replacement was electrical and HVAC supply websites. That TEDSS site is the only place I was able to find the correct part.

The cap in my set shorted out without warning after the set was on for a couple of hours. It'll pop the circuit breaker on the back when it shorts.
I replaced it with a cap I had from a parted out set, but who knows how long that one will last.
That's okay, I already got one from Brian, and I reckon NOS units show up on eBay from time to time. If all else fails I'll use the TEDSS site.

My Electrohome doesn't have a breaker, just a 2-amp fuse. If that ever goes I might put in a breaker, perhaps in the place of the Instavu switch. I don't want to put another hole in the back.
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