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#1
Posted to rec.audio.marketplace,rec.audio.tubes,rec.audio.forsale
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market for large electrolytic capacitors?
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* |
#2
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
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 |
#3
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
"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* |
#4
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
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! |
#5
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
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 |
#6
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
"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* |
#7
Posted to rec.audio.marketplace,rec.audio.tubes,rec.audio.forsale
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market for large electrolytic capacitors?
"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 |
#8
Posted to rec.audio.marketplace,rec.audio.tubes,rec.audio.forsale
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market for large electrolytic capacitors?
"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* |
#9
Posted to rec.audio.marketplace,rec.audio.tubes,rec.audio.forsale
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market for large electrolytic capacitors?
"Phil Allison"
** Worth almost nothing. Even less, if they have never been used. BTW, do electrolytics of the early 1980s contain PCBs? *TimDaniels* |
#10
Posted to rec.audio.marketplace,rec.audio.tubes,rec.audio.forsale
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market for large electrolytic capacitors?
"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 |
#11
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
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. |
#12
Posted to rec.audio.marketplace,rec.audio.tubes,rec.audio.forsale
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market for large electrolytic capacitors?
"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* |
#13
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
"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* |
#14
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
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 |
#15
Posted to rec.audio.marketplace,rec.audio.tubes
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market for large electrolytic capacitors?
"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* |
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