[Collins] Re: black beauty

[Dr. Gerald N. Johnson, electrical engineer]

If I'd been making the capacitor choices, they wouldn't have been plain
paper black beauties, they'd have been orange drops or paper/polyester
black beauties. I had become acquainted with orange drops and their
ruggedness and lack of leakage even when abused several years before I
began to work at Collins. I began in the summer of 1963.

Collins Radio Company generally did work for quality, to the extent that
there was a specification for every part ever used or proposed to be
used. Those parts specifications were written by a special department at
the request (and project cost) of engineers. Qualifications generally
included prototype or production components life tests (at project cost)
as well as specification tests. Then to make design decisions more
consistent, there was a book of "preferred" parts specifications. And a
book of design details.

That being said, Art was a man of connections. When one of my
neighboring engineers proposed using RCA 8122 tubes in place of Eimac
4CX350 (69 cent socket versus $10, tube price less than half), and put
that into the standard working paper, Art said, "We'll use Eimac, I've
known Bill Eitel since 1934." Neither part quality nor cost played in
that decision. Old crony did affect that decision. For a while, the
small Eimac tubes did prove to have better reliability than the RCA 8122
though eventually Eimac made them also. Then the 4CV100,000C PA tubes
used in the 821A-1 from Eimac were marginal and later production from
Machlett (not funded by Collins like the Eimac development as far as I
know) survived much better than the Eimac designs.

When I was at Collins, any new design or part of a design was reported
in a "working paper." That working paper would disappear into "the
system." In a few working days the engineer's boss (group head) would
receive a call from Art (my boss in Ceder Rapids had a lower badge
number than Art, single digit as I recall) and Art would say, "I like
it," or "I don't like it. Don't do it." I've heard that he occasionally
said (to a broadcast modulation transformer with PA plate current in the
secondary): "That didn't work in 1937, it won't work now." With that he
ignored weeks or months of design work and the existence of new core
materials and new design techniques that might have made the design work
while being more compact and far less costly. I don't think Art was
keeping up with all the state of the art of materials and components.
But this procedure with the working papers kept Art's fingers into the
details of every project even where he wasn't necessarily the most
competent.

Considering that before polyester film capacitors, the molded oil kraft
paper capacitors were the best available commercial capacitors compared
to the wax coated kraft paper capacitors common in 50s and 60s vintage
consumer radio and TV products. I'd say that black beauties were about
as good as could be had without polyester. However I recall noticing
that industrial electronics as well as consumer products rapidly adopted
the polyester capacitors because they are often more compact and keep
circuits working correctly for much longer operating periods. Then
probably the Black Beauties cost less than Orange drops or the
equivalents from other makers. In a "low cost" radio like the KWM2 and
S-line (counter to Art's ideal of a radio that only the elite could
afford), parts price was a consideration in the design and production.

Designers may have used Black beauties from habit, production may have
wished for Black beauties for cost or to use up a large quantity in the
main stock warehouse. Art may have said, "Let's use those fine Black
beauty capacitors. I've known xxxxx from Sprague since 1933..." He
certainly would have used oiled kraft paper capacitors from the
beginning of his construction because the polyester capacitors were new
in the late 50s and early 60s.

Vitamin Q cost several (like 5 to 10) times as much as black beauties.
And sometimes leak as badly as Black beauties. And sometimes are larger,
definitely are heavier than Black beauties requiring special mountings
for vibration.

73, Jerry, K0CQ, Technical Advisor to the CRA.
-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.