[R-390] killer and mica caps

[Bob Camp]

Hi

If you have ever visited a film and foil plant, it’s pretty basic. The advances in equipment 
have more to do with speed of manufacture than anything else. To the extent there is a 
“secret sauce” it’s in paying attention to the quality of your raw material. For the last two decades
at least, that a function of “buy it from the right guy” rather than in-house testing. There are certainly 
a number of errors you can make as they go down the line, it’s rare to see them show up 
in purchased product. 

You might ask: But what about tight tolerances? Well, they do them by squeezing the cap before
it is epoxy coated. There is a “fast aging” process after than to take out he strain. Once upon a time
it was some really good gal doing pushing on the part and watching the C meter. Those days are
long gone, there’s a squeeze machine these days. For the really tight stuff they age it for a few
months and then re-sort. That’s never been a cheap process …..

Bob


> On Oct 11, 2016, at 9:25 PM, Charles Steinmetz <csteinmetz at yandex.com> wrote:
> 
> Chris wrote:
> 
>> How about ASC film caps?  I just learned and verified that one at least
>> one value of both the X675 series and X363 series are indeed made in the
>> USA.
> 
> All of the ASC "Xyyy" Series caps are metallized film, not film and foil. The X363 Series only goes up to 400v.  The X675 Series comprises specialized high voltage caps (2kV and up), which have some design tradeoffs that we don't need to accept in applications below 1kV.  I would not recommend either for tube radio or audio erquipment.
> 
> ASC does make some film and foil types in both polypropylene and polyester, for example the 368, 321, 621, 668, 663, 663F, and 621 Series.  From what I have seen, these may be worth considering -- but ASC is not really a "large" capacitor manufacturer, so that would need to be proven over time.
> 
>> It's unfortunate that the Orange Drops are now exclusively made overseas.
> 
> I'm not sure that is true, and even if it is, I'm not sure that it has negative implications.
> 
> Here's the history of the Orange Drop line:  Sprague started making the basic design in a factory in Vermont where they were developed for use in bomb and missile fuses during WW2, and adopted the trade name "Orange Drop" for the line in the late 1950s.  In 1985, Sprague sold the OD line, including the production facilities, to SBE.  SBE continued to manufacture ODs in that same factory until it sold the line to CDE in 2012.  CDE continued to produce them in that same factory, but said at the time that it planned to move production to other CDE facilities.
> 
> That change has probably been made by now, but I have not heard whether OD production moved to facilities in the US or overseas.  So far, all of the CDE "Country of Origin" slips I have seen say "USA," and distributors still list CoO as "USA."  There has been lots of uninformed chatter on the web claiming that CDE ODs are now made in Mexico and/or China, but I have seen no evidence of that as recently as this summer.
> 
> Furthermore, factories all over the world are fully capable of equalling and even bettering the quality of US-made capacitors.  It all depends on what the management does.  It is entirely possible that ODs are being made today on the very same machinery that the factory in Vermont was using.  It is also possible that they are being made in a brand-new, state-of-the-art factory where tolerances and materials are held to much tighter tolerances than in the VT factory.
> 
> In either case, that facility may be in the US, or it may be in Mexico, or India, or China.  It probably makes no difference in the quality of the capacitors, and could even mean that quality has improved.
> 
> Best regards,
> 
> Charles
> 
> 
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