[Timothy Daniels]

I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100vdc),
and I can't think of where to sell them besides eBay.
Any suggestions on where a guy could sell a third of a
farad?

*TimDaniels*

[Peter Wieck]

On Jan 26, 3:22*am, "Timothy Daniels"
wrote:
I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100vdc),
and I can't think of where to sell them besides eBay.
Any suggestions on where a guy could sell a third of a
farad?

*TimDaniels*

A few things:

a) Caps are cheap. Even big ones. Most of us who use/replace
electrolytics need to know their provenance. Vintage caps, caps that
have been sitting on shelves for 20 years are of questionable
utility.

b) 100VDC would be more useful in solid-state applications -
typically. As Tube applications tend to run to much higher voltages.

Good luck, otherwise. eBay is likely your best venue as you will be
exposed to many more potential buyers who just might have that sort of
need.

Peter Wieck
Melrose Park, PA

[Timothy Daniels]

"Peter Wieck" wrote:
--------------------------
a) Caps are cheap. Even big ones. Most of us who use/replace
electrolytics need to know their provenance. Vintage caps, caps
that have been sitting on shelves for 20 years are of questionable
utility.

b) 100VDC would be more useful in solid-state applications -
typically. As Tube applications tend to run to much higher voltages.

Good luck, otherwise. eBay is likely your best venue as you will be
exposed to many more potential buyers who just might have that sort of
need.

Peter Wieck
Melrose Park, PA
----------------------------

Thanks. I didn't know that electrolytics aged on the shelf.
Is there a simple way to test them?

*TimDaniels*

[PeterD]

On Mon, 26 Jan 2009 10:39:15 -0800, "Timothy Daniels"
wrote:

"Peter Wieck" wrote:
--------------------------
a) Caps are cheap. Even big ones. Most of us who use/replace
electrolytics need to know their provenance. Vintage caps, caps
that have been sitting on shelves for 20 years are of questionable
utility.

b) 100VDC would be more useful in solid-state applications -
typically. As Tube applications tend to run to much higher voltages.

Good luck, otherwise. eBay is likely your best venue as you will be
exposed to many more potential buyers who just might have that sort of
need.

Peter Wieck
Melrose Park, PA
----------------------------

Thanks. I didn't know that electrolytics aged on the shelf.
Is there a simple way to test them?

Like using a capacitor tester? Naw, that'd be much too easy!

[Peter Wieck]

On Jan 26, 3:35*pm, PeterD wrote:

Like using a capacitor tester? Naw, that'd be much too easy!

Actually, it just might be. Not all cap testers are created equal. The
one on your VOM will read mildly leaky electrolytics as 'high' and
given the standard tolerance of +100/-10%, that could be problematic.
And even if they do not leak at the half-dozen test volts from your
VOM, they might well leak at 450 volts. Or explode.

And an ESR meter is a bit more indicative than a simple VOM-based
tester, but again does not typically reach actual operating voltages.

So, unless your tester actually does test at full operating voltages,
it is, in fact, much too easy.

Even after buying new stock, I still test any high-voltage cap on my
bench tester before it goes into the unit. Once in a great while, I
find one that is leaky from the git-go at its rated voltage - but
tests just fine on the Fluke VOM.

So, to answer Tim's question: Yes, but only if you have a full-voltage
cap-tester on your bench. There are rude/crude tests otherwise, but
caps of that size do not respond well to them.

Peter Wieck
Melrose Park, PA

[Timothy Daniels]

"Peter Wieck" wrote:
-------------------------------
PeterD wrote:

Like using a capacitor tester? Naw, that'd be much too easy!

Actually, it just might be. Not all cap testers are created equal. The
one on your VOM will read mildly leaky electrolytics as 'high' and
given the standard tolerance of +100/-10%, that could be problematic.
And even if they do not leak at the half-dozen test volts from your
VOM, they might well leak at 450 volts. Or explode.

And an ESR meter is a bit more indicative than a simple VOM-based
tester, but again does not typically reach actual operating voltages.

So, unless your tester actually does test at full operating voltages,
it is, in fact, much too easy.

Even after buying new stock, I still test any high-voltage cap on my
bench tester before it goes into the unit. Once in a great while, I
find one that is leaky from the git-go at its rated voltage - but
tests just fine on the Fluke VOM.

So, to answer Tim's question: Yes, but only if you have a full-voltage
cap-tester on your bench. There are rude/crude tests otherwise, but
caps of that size do not respond well to them.

Peter Wieck
Melrose Park, PA
---------------------------

That's why the potential buyer would be a hobbyist with
testbench equipment which I don't have. To most people
nowadays, 5v switching power supplies and active regulators
are the norm, but I know *somewhere* out there, these huge
caps with their 100wvdc rating would be golden. But how to
find such hobbyists?

*TimDaniels*

[Phil Allison]

"Timothy Daniels"

I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100vdc),



** Worth almost nothing.

Even less, if they have never been used.



....... Phil

[Timothy Daniels]

"Phil Allison" wrote:

"Timothy Daniels"

I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100vdc),



** Worth almost nothing.

Even less, if they have never been used.



...... Phil


Thanks for your assessment.

*TimDaniels*

[Timothy Daniels]

"Phil Allison"
** Worth almost nothing.

Even less, if they have never been used.


BTW, do electrolytics of the early 1980s contain
PCBs?

*TimDaniels*

[Phil Allison]

"Timothy Daniels"
"Phil Allison"
** Worth almost nothing.

Even less, if they have never been used.


BTW, do electrolytics of the early 1980s contain
PCBs?


** No.

PCBs are " di-electrics fluids " not " electrolytes ".

They are normally only found in non-polarised caps - the oil filled
types.

http://en.wikipedia.org/wiki/Polychlorinated_biphenyl



..... Phil

[WindsorFox[_4_]]

Timothy Daniels wrote:
"Phil Allison" wrote:
"Timothy Daniels"

I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100vdc),


** Worth almost nothing.

Even less, if they have never been used.



...... Phil


Thanks for your assessment.

*TimDaniels*



His assessments are usually worth at least what you paid for it....

--



"Pot, thy colour is black, thy material make-up is primarily of iron and
thy criminal record is that of soliciting for the purpose of
prostitution." - Marc B.

[Timothy Daniels]

"Phil Allison" wr0teP

"Timothy Daniels"
"Phil Allison"
** Worth almost nothing.

Even less, if they have never been used.


BTW, do electrolytics of the early 1980s contain
PCBs?


** No.

PCBs are " di-electrics fluids " not " electrolytes ".

They are normally only found in non-polarised caps -
the oil filled types.

http://en.wikipedia.org/wiki/Polychlorinated_biphenyl



.... Phil


Thanks, Phil. I won't have to take the caps to the
toxic waste disposal depot it I throw them out.

*TimDaniels*

[Timothy Daniels]

"WindsorFox[SS]" wrote:
-------------------------------
"Phil Allison" wrote:
"Timothy Daniels"

I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100vdc),


** Worth almost nothing.

Even less, if they have never been used.



...... Phil


Thanks for your assessment.

*TimDaniels*


His assessments are usually worth at least what you paid for it....

-----------------------

Thanks for that assessment, too. :-)

*TimDaniels*

[Patrick Turner]

Timothy Daniels wrote:

"Phil Allison" wr0teP

"Timothy Daniels"
"Phil Allison"
** Worth almost nothing.

Even less, if they have never been used.


BTW, do electrolytics of the early 1980s contain
PCBs?


** No.

PCBs are " di-electrics fluids " not " electrolytes ".

They are normally only found in non-polarised caps -
the oil filled types.

http://en.wikipedia.org/wiki/Polychlorinated_biphenyl



.... Phil

Thanks, Phil. I won't have to take the caps to the
toxic waste disposal depot it I throw them out.

*TimDaniels*

I used electro caps that were 30 years old and which may have been
laying around unused for many years and found all have worked as
planned, and none have exploded or failed. These were mainly pulls from
gear I know nothing about. Some were 1,500uF x 450V and 40 years old
from old university laboratory gear and they have worked fine for many
years after I put them in a tube amp 7 years ago.

Old caps are regarded as commercially unsaleable, but if they work OK,
then why throw them out if you have a use for them or you know someone
who might use them?

The informed electronics person will be wary, and gradually bring up the
working Vdc across the cap via a high value resistance from an
adjustable dc voltage supply. This "reforms" the electrolytic capacitor.
If electrolyte inside the elecap has leaked out then the cap will fail
to a short or remain a much lower C than it should be. OK, *then* you
chuck them into the re-cycle bin.

I won't use old "paper" plus foil caps though. Plastic caps made after
polyester was invented in 1949 are often as good as the day they were
made in 1955, even after spending 50 years in some old radio.

In new equipment I supply to customers, i always use NEW or recently
made caps everywhere.

I've never had a cap failure unless its because an output tube became
saturated and the anode current from the PSU became high thus sending
the ripple current high thus making the cap fail from the heat of being
in tube gear combined with the excessive ripple current.

I've got some Sprague el-caps of 100,000 uF and for 75Vdc working, and
with 5mm screw thread post terminals for high current handling.
They are in good condition and I see no reason why they wouldn't be
usable in 10 years time if I wanted to use them.


Patrick Turner

[Timothy Daniels]

"Patrick Turner" wrote:
I used electro caps that were 30 years old and which may have been
laying around unused for many years and found all have worked as
planned, and none have exploded or failed. These were mainly pulls from
gear I know nothing about. Some were 1,500uF x 450V and 40 years old
from old university laboratory gear and they have worked fine for many
years after I put them in a tube amp 7 years ago.

Old caps are regarded as commercially unsaleable, but if they work OK,
then why throw them out if you have a use for them or you know someone
who might use them?

The informed electronics person will be wary, and gradually bring up the
working Vdc across the cap via a high value resistance from an
adjustable dc voltage supply. This "reforms" the electrolytic capacitor.
If electrolyte inside the elecap has leaked out then the cap will fail
to a short or remain a much lower C than it should be. OK, *then* you
chuck them into the re-cycle bin.

I won't use old "paper" plus foil caps though. Plastic caps made after
polyester was invented in 1949 are often as good as the day they were
made in 1955, even after spending 50 years in some old radio.

In new equipment I supply to customers, i always use NEW or recently
made caps everywhere.

I've never had a cap failure unless its because an output tube became
saturated and the anode current from the PSU became high thus sending
the ripple current high thus making the cap fail from the heat of being
in tube gear combined with the excessive ripple current.

I've got some Sprague el-caps of 100,000 uF and for 75Vdc working, and
with 5mm screw thread post terminals for high current handling.
They are in good condition and I see no reason why they wouldn't be
usable in 10 years time if I wanted to use them.


Patrick Turner

Thanks for sharing your experience, Patrick. I'll keep looking for
someone who could use these. It was such a search to find them
originally that I'd hate to just throw them away. Maybe I'll try some
of the local universities as recipients of a (tax-deductible) donation.
I wonder if the Internal Revenue Service knows what a "Farad" is.
:-)

*TimDaniels*