View Full Version : Zenith 25NC38 - hard to find 475 volt electrolytic capacitors


Adam
11-22-2006, 06:44 PM
Anyone have any leads on where to find some of these?
And here's a pic of the set I'm working on.

polaraman
11-22-2006, 07:57 PM
www.tubesandmore.com

Antique radio supply

www.mouser.com

polaraman

drh4683
11-22-2006, 08:12 PM
Ive always had good luck with mouser. They will also send you their huge 2.5" thick catalog everymonth for free. I bought caps from them when I restored my CTC-7 two years ago and have been getting the monthly catalog ever since. They have a great selection on caps of many brands. Sprage "atom" caps are the best imo, (USA made too), but they are extremely large in size. You might have trouble fitting them (the 100uf@450v) under the chassis. Ive used the xicon brand lytics and they work fine much smaller for the same ratings. The most you'll pay is around $5-7 a cap for the xicon 100@450's.

peverett
11-23-2006, 03:33 PM
I just picked up some new 33ufd@500 volts (Chinese made) capacitors at a radio meet flea market. If Mouser or Antique Electronic Supply does not have what you need, I could sell a couple.

You also might try Moyers:
http://www.moyerelectronics.com
You may need to call them.

Randy Bassham
11-23-2006, 08:10 PM
I use Mouser alot, I placed an order on Tuesday Nov 14 and UPS delivered it on the afternoon of the 15th. I never fail to get things very quickly and as an added bonus I can heat the house with all the old catalogs.....

Adam
11-24-2006, 06:13 PM
Thanks for your replies. I've been looking around these websites, and am I missing something here, or does nobody carry 100mfd-500v. I know I could put some in parallel, but I'd rather not.

"" You might have trouble fitting them (the 100uf@450v) under the chassis. Ive used the xicon brand lytics and they work fine much smaller for the same ratings. The most you'll pay is around $5-7 a cap for the xicon 100@450's.""

So do the 450s work as replacements for the 475s? If so I already have most of what I need.

peverett
11-24-2006, 06:42 PM
Although I have seen plenty of 100 ufd, etc. capacitors at 450 volts, I have not seen many above this rating. This is why I picked up the 33ufd at 500 volts when I saw them. These were the largest values the seller had and , according to the seller, they were the last production of the 500 volt ones.

450 volt caps might work, but if the voltage surge is above 450 volts, failure might occur. I suspect 475 volt caps were specified for a reason.

As to my 500 volt caps, they are Chinese made, so I am not sure of the quality yet. I have used one in restoring an Admiral B&W TV where a 475 volt cap was specified and had no issues to date. I just finished the restoration, so the jury is sill out.

kx250rider
11-25-2006, 12:16 PM
Adam,

Check at All Electronics (on Oxnard St just west of Kester). They get a few weird electrolytics now & then. I bought a whole box of 4 x 20 @ 450 cans there for a quarter each :music: ... That was a while ago though. I've definitely seen 500-volt cans there too. No promises...

Charles

Adam
11-25-2006, 04:10 PM
I checked them out, nothing over 450volts. They did have some 180mfd-450v, that I might go back for and use for the 160mfd-250v, but they're that awful kind with the short flat leads, so I'm going to look around for something else first.
I did pick up a big box of early infrared Zenith remotes. Turned out that most of them don't work on my sets though, all the ones that say Z-TAC on them. So if anyone needs one of these Z-TAC remotes, let me know, but they don't work on System III televisions.

Chad Hauris
11-25-2006, 05:10 PM
There is a JJ brand 50/50 at 500 volt we have used on a lot of different devices and they have worked great.

kbmuri
11-25-2006, 06:56 PM
Adam -

You mentioned something about paralleling capacitors. There's a good concise theory-discussion here (for those interested):

http://www.oz.net/~coilgun/theory/capacitors2.htm

Mouser part numbers TVA-1906, TVA-1907, TVA-1908 are 20mf, 30mf, and 40mf, respectively, 500V, genuine Sprague, good choices, but are physically large and aren't cheap. But are top-quality units.

I recently tried these Cornell-Dubilier snap-mounts with good results. They're 1/3 the size and 1/3 the price, but they seem to work at least in the short term. I don't have any long-term results to give an opinion, but the quality seems acceptable.

http://www.mouser.com/search/ProductDetail.aspx?R=380LX470M500J012virtualkey598 50000virtualkey5985-85-500V47

You have to be a little more creative installing them (the snap-mounts are for PCB's, not hand-wired chassis). But I found with clever wiring, they do stack and hide in old multicap cans very well.

Here are some 100mfs:
http://www.mouser.com/search/Refine.aspx?Ne=1447464+254016&Ntt=*500V*+*electrolytic*+*100uf*&Msb=0&Mkw=500V+electrolytic+100uf&N=1323038+0

Not currently in stock though, so you'd probably have to call.

Adam
11-25-2006, 07:20 PM
""You mentioned something about paralleling capacitors to make your voltage ratings. Please read this first. http://www.oz.net/~coilgun/theory/capacitors2.htm""

Thanks for the info, but I just wasn't being clear about the parallel caps. I meant paralleling 40 and 20mfd 500v caps to increase the capacitance. But needing to make both an 80 and a 100mfd capacitor with those values, I'd need to stuff 5 capacitors down there just to replace those 2 and then I'd really have space problems under the chassis, so I'm trying to avoid that if I can.

kbmuri
11-25-2006, 09:10 PM
I bet you'd be really happy with the 100mfd snap-ins if you could find a supplier. We know they're out there, but I think Mouser has to get them in quantity to get them at all. Maybe check these?

http://www.cde.com/new/directory/dist/us.html

kbmuri
11-25-2006, 09:23 PM
Allied seems to have 166 of them:
http://cdenb2.cde.com/distinv.htm?PARTNO=380LX101M500J042

kbmuri
11-25-2006, 09:24 PM
Cheep too!


http://www.alliedelec.com/Search/SearchResults.asp?N=0&Ntk=Primary&Ntt=380LX101M500J042&sid=456787804769617F