Source for 20/20 and 20/40 mfd 150V capacitors?

[Harry Conover]

Can anyone here suggest a source for NEW 20/20 or 20/40 mfd, dual
section, 150V electrolytic capacitors for use in the restoration and
repair of old ac/dc radios? I'm also interested in 20 and 30 mfd,
450V cans.

Harry C.

 

[Tweetldee]

http://www.tubesandmore.com/
http://www.radiodaze.com/
http://www.dialcover.com/components.html

--
Dave M

Never take a laxative and a sleeping pill at the same time!!!
"Harry Conover" <hhc314@yahoo.com> wrote in message
news:7ce4e226.0402071541.7283f1ec@posting.google.com...

Can anyone here suggest a source for NEW 20/20 or 20/40 mfd, dual
section, 150V electrolytic capacitors for use in the restoration and
repair of old ac/dc radios? I'm also interested in 20 and 30 mfd,
450V cans.

Harry C.

 

[Harry Conover]

"Tweetldee" <masondg4499@comcast99.net> wrote in message news:<hMsVb.120121$U%5.598947@attbi_s03>...

http://www.tubesandmore.com/
http://www.radiodaze.com/
http://www.dialcover.com/components.html

--
Dave M

Dave, many thanks for posting this.

Harry C.

 

[Jan-Erik Söderholm]

Hi.
Thats micro (not milli) Farads, right ?

Anyway, I have some 22uF/400V and 33uF/400V, 105C, long lofe
(new) caps.

See : www.st-anna-data.se under the "Electronic-Surplus" menu.

Regards
Jan-Erik.

Harry Conover wrote:

Can anyone here suggest a source for NEW 20/20 or 20/40 mfd, dual
section, 150V electrolytic capacitors for use in the restoration and
repair of old ac/dc radios? I'm also interested in 20 and 30 mfd,
450V cans.

Harry C.

 

[Harry Conover]

Jan-Erik Söderholm <aaa@aaa.com> wrote in message news:<4027E6E2.199AAC9E@aaa.com>...

Hi.
Thats micro (not milli) Farads, right ?

No, mfd is the traditional acronym for millifarads. The dual section
20/20 and 20/40 mfd. capacitors were a standard component of most
ac/dc radios produced from WWII though (roughly) the 1960s. Dual
section, tubular electrolytics in these values and rated for at least
150 WVDC are now difficult to find. (They're easily functionally
replicated using contemporary products, but it's not the same thing.)

I'm quite sure that there is a cache of these NOS components lurking
somewhere in a warehouse (just as old 1949 Erector Sets and Lionel
Trains in unopened boxes turn up from time to time). The game, no the
challenge, is in being the first one to find and unearth them.

Such motivation is a collector thing, difficult to comprehend for
non-collectors.

Harry C.

 

[John G]

"Harry Conover" <hhc314@yahoo.com> wrote in message
news:7ce4e226.0402092103.6a4b8033@posting.google.com...

Jan-Erik Söderholm <aaa@aaa.com> wrote in message
news:<4027E6E2.199AAC9E@aaa.com>...
Hi.
Thats micro (not milli) Farads, right ?

No, mfd is the traditional acronym for millifarads. The
dual section
20/20 and 20/40 mfd. capacitors were a standard component
of most
ac/dc radios produced from WWII though (roughly) the
1960s. Dual
section, tubular electrolytics in these values and rated
for at least
150 WVDC are now difficult to find. (They're easily
functionally
replicated using contemporary products, but it's not the
same thing.)

I'm quite sure that there is a cache of these NOS
components lurking
somewhere in a warehouse (just as old 1949 Erector Sets
and Lionel
Trains in unopened boxes turn up from time to time). The
game, no the
challenge, is in being the first one to find and unearth
them.

Such motivation is a collector thing, difficult to
comprehend for
non-collectors.

Harry C.
Harry,

In 50 years in electronics from WWII aircraft to Pentium and
beyond
I have never seen mfd used as Milli but always as Microfarad
and anyway
a 20millifarad 150 volt capacitor would be tooo big to fit
on your workbench I think.
--
John G

Wot's Your Real Problem?

 

[Richard Crowley]

Jan-Erik Söderholm wrote ...
Thats micro (not milli) Farads, right ?

"Harry Conover" wrote ...

No, mfd is the traditional acronym for millifarads.

No, "mfd" is the tradtional aconym for MICROfarads.

Note that this dates from the days before we learned how
to use the Greek lower-case "mu" symbol (?). Sometimes
seen as uF (with conventional lower-case U masquerading
as the "mu" character for those without the full character-
set.)

TODAY, of couse, "m" means MILLI (as in mW, mV, etc.)
But in the vintage of those old fire-bottle capacitors,
mfd (or MFD) was definitely *MICRO*FARADS.

And to complete the history lesson, mmF (micro-micro-
Farads) was used before "pico" came into common use.
8 mmF is what today we would call 8 pF (picoFarads)

A 20 milli-farad high-voltage capacitor would approach
the size of the whole equipment.

 

[Harry Conover]

"John G" <Greentest@ozemail.com.au> wrote in message news:<8s1Wb.126$NS3.5748@nnrp1.ozemail.com.au>...

Harry,
In 50 years in electronics from WWII aircraft to Pentium and
beyond
I have never seen mfd used as Milli but always as Microfarad
and anyway

a 20millifarad 150 volt capacitor would be tooo big to fit
on your workbench I think.

John, you caught me in a big goof. Obviously mfd refers to
microfarads. I was trying to make a distrinction between mfd and mmf
(now termed pF).

Hey, it's only an error of three orders of magnitude!

Thanks for calling attention to it.

Harry C.

 

[Jan-Erik Söderholm]

Richard Crowley wrote:

No, "mfd" is the tradtional aconym for MICROfarads.

Note that this dates from the days before we learned how
to use the Greek lower-case "mu" symbol (?). Sometimes
seen as uF (with conventional lower-case U masquerading
as the "mu" character for those without the full character-
set.)

And the "u" is *MUCH* better then the "m" for "micro", IMHO...

Jan-Erik.

 

[Harry Conover]

Jan-Erik Söderholm <aaa@aaa.com> wrote in message news:<40295993.E27BF1B@aaa.com>...

Richard Crowley wrote:
No, "mfd" is the tradtional aconym for MICROfarads.

Note that this dates from the days before we learned how
to use the Greek lower-case "mu" symbol (?). Sometimes
seen as uF (with conventional lower-case U masquerading
as the "mu" character for those without the full character-
set.)

And the "u" is *MUCH* better then the "m" for "micro", IMHO...

Why do you believe this, since the Greek letter 'mu' is symbolized in
our alphabet by the letter 'm', hence what you see sort of looking
like a 'u' with a decending leading edge, is really an 'm'. Let's cut
to the basics:

http://physics.nist.gov/cuu/Units/prefixes.html

Note that the SI symbology for 'micro' is represented by the Greek
letter "mu", represented in our alphabet as 'm'. See:

http://www.ibiblio.org/koine/greek/lessons/alphabet.html

More than any other book that I could lay my hands on, "The ARRL
Handbook" over the years avoided the symbology issue almost entirely,
by simply labeling mfd value capacitors with a decimal value, say
0.01, and mmf value capacitors with an integer value such as 56. This
works for me. In the older issues (I checked the 1961 issue),
sometimes you'd see an occasional 'mf' or the Greek character 'mu',
but not a 'u' or a 'p' designation in the entire book. The same
pattern held true in the 1990 issue.

In my copy of Horowitz and Hill's "The Art of Electronics" (my copy is
the 4th printing dated 1998), the same pattern is followed as in the
ARRL publications, with one notable exception. The double Greek letter
symbology for 'micro-micro farad' has been replaced by pf. If you ask
me, this is not a significant or particularly productive change,
except for easing the job of typesetters!
Harry C.

p.s., Management organizations and Europeans both delight in promoting
unnecessary changes to existing systems that already work rather well,
if for no other reason than to simply call attention to something --
What that something is I'm still trying to determine!

 

[Richard Crowley]

Jan-Erik Söderholm wrote...
And the "u" is *MUCH* better then the "m" for "micro", IMHO...

"Harry Conover" wrote ...

Why do you believe this, since the Greek letter 'mu' is symbolized in
our alphabet by the letter 'm',

And there lies the problem. "m" is also used for "milli" as in
mW (milli-Watts), mV (milli-Volts), mA (milli-Amps), mm
(milli-metres), etc. etc. ad nauseum.

"u" (the cheap-n-dirty Anglicized stand-in for "mu") is far preferable
for "micro" IMHO. No opportunity for confusion with the same letter
indicating the next higher multiplier.

 

[J. Yazel]

In my copy of Horowitz and Hill's "The Art of Electronics" (my copy is
the 4th printing dated 1998), the same pattern is followed as in the
ARRL publications, with one notable exception. The double Greek letter
symbology for 'micro-micro farad' has been replaced by pf. If you ask
me, this is not a significant or particularly productive change,
except for easing the job of typesetters!
Harry C.

=========================

I wondered whatever happend to mickey-mike. (g)

Jack

 

[Harry Conover]

J. Yazel <jyazel@netset.com> wrote in message news:<7h8l20tq7jebj0ic822nsllpt21v9voub6@4ax.com>...

In my copy of Horowitz and Hill's "The Art of Electronics" (my copy is
the 4th printing dated 1998), the same pattern is followed as in the
ARRL publications, with one notable exception. The double Greek letter
symbology for 'micro-micro farad' has been replaced by pf. If you ask
me, this is not a significant or particularly productive change,
except for easing the job of typesetters!
Harry C.

=========================

I wondered whatever happend to mickey-mike. (g)

Jack

It went the way of the "Wouff Hong", with its notorious brown stains!

Harry C.

 

[Michael A. Terrell]

"J. Yazel" wrote:

I wondered whatever happend to mickey-mike. (g)

It had an operation, and changed its name to "Pickle Fart" ;-)

--
We now return you to our normally scheduled programming.

Michael A. Terrell
Central Florida