Re: Can capacitors

Chuck Harris <cfharris@...>

Not to put you on the spot, but can you share with
us the types of failures you witnessed in these new
manufacture can capacitors?

It might allow us to determine what they are doing wrong.

For instance, can capacitors were originally made during
the era where the capacitor's aluminum wasn't pre anodized
before construction. They anodized it in place by
applying a current limited peak required voltage.

Capacitors built during that era have a much more reactive
(to aluminum) electrolyte, than do current manufacture

There have been many electrolyte failures since the
industrial espionage days when spies from China stole
bogus files detailing one highly regarded manufacturer's
recipe.. and hundreds of Chinese manufacturers, and a
few Japanese, made little time bombs using the purloined

-Chuck Harris

greenboxmaven via wrote:

I agree that, regrettably, these condensers do not measure up in reliability. I
worked at a sound equipment boutique and  had about a 10% failure rate of these
condensers within three years.   They are also quite expensive, which is justified by
the small production volume and labor of making them.  I have two old sound
amplifiers of my own that had these condensers installed before I got them, and they
have all failed less than ten years after they were made. I hope the manufacturers
will take these statistics seriously and improve their quality. Meanwhile, I will
continue opening old ones, removing the failed windings, and replacing them with
modern individual condensers.

     Bruce Gentry, KA2IVY

On 12/5/20 11:55, Roy Thistle wrote:
On Sat, Dec  5, 2020 at 07:40 AM, Tom Phillips wrote:

There is a video series on the page at < >
which shows the can cap manufacturing process using the old Mallory equipment.
It is interesting. The materials handling and process quality control are, of
course, not up to modern standards and the resulting caps are not as reliable
as the original Mallory parts. However, they have been successful with their
niche market customers.

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