[NJARC] non-Polarized Capacitors

[John Ruccolo]

Hi Al/Folks,

I wonder -- does it matter if you connect the negative leads together or the positive leads, as long as they're "back to back?" (*not* in series, of course).

The larger mylar film caps are surprisingly expensive. I recently ordered some 1UF/630V for the club, and they were 2.26 apiece. I wonder what 4.7's or 10's or 22's cost from Mouser; they must be pretty pricey. I'll check the catalog or online.

Of course, if you're rebuilding a really good quality pair of speakers, then they're worth it.

Regards,

John R.

--- On Sun, 10/18/09, Al Klase <al at ar88.net> wrote:

> From: Al Klase <al at ar88.net>
> Subject: Re: [NJARC] non-Polarized Capacitors
> To: "NICHOLAS SENKER" <ns539 at embarqmail.com>
> Cc: "njarc at mailman.qth.net NJARC" <njarc at mailman.qth.net>
> Date: Sunday, October 18, 2009, 3:38 PM
> Just remember 
> Reply = Poster
> Reply All = Everyone
> 
> _________________________________________________________
> Nick's right.  The commercial non-polarized
> electrolytics amount to 
> being back to back polarized units, and that makes an
> acceptable 
> substitute.  However, in my limited experience
> rebuilding vintage 
> speakers, the years have not been kind to these
> things.  They change 
> value significantly with age, and in speakers, especially a
> stereo pair, 
> this has audible implications.
> 
> There are high value, 2.3, 4.7, 10, 22 uF, metalized
> polyester caps 
> floating around that can be series-paralleled to get you
> where you need 
> to be, and their values should remain constant for many
> decades.
> 
> Let me know what you need, and I'll rifle through the
> boxes.
> 
> Al
> 
> NICHOLAS SENKER wrote:
> > Just remember 
> > Reply = Poster
> > Reply All = Everyone
> >
> >
> _________________________________________________________
> > For John Rucollo and Steve Colandra; we were
> discussing non-polarized caps for speaker crossovers; these
> are available commercially and I think I have some; will
> bring them to the swapmeet.
> > According to my Popular Science 'How to build your own
> Radio and Hi-Fi' manual; you can make your own non-polarized
> caps by connecting two regular electolytics
> 'back-to-back'.  Connect the negative leads together
> and use the positive leads for speaker connections.
> > For a 2000 hz crossover at 8 ohms, you need a 10 mfd
> cap but if you put two caps in series as above you need
> twice the capacitance; in this case, 20 mfd each.
> > Nick Senker 
> >
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> 
> -- 
> Al Klase - N3FRQ
> Jersey City, NJ
> http://www.skywaves.ar88.net/
> 
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