Hello,
Does someone know the manufacturer associated with this logo ( letter "R" inscribed in rounded square ) ? It's an old capacitor with build date 1999 so we might need to jug our collective memory 😎. It's propably a Rubycon but the cap is too small to write in full. This cap was built at the beginning of the infamous "capacitor plague" era and I need to confirm it is not from an affected manufacturer.
It would be nice to have a table with manufacturer logos both current and historic, I found some "general equipment" ones of for ICs on the net but none specific to capacitors. Perhaps someone here knows of one?
Thanks in advance!
Joris
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Yep, Rubycon. See here for an example: https://www.digikey.com/en/products/detail/rubycon/25MH710MEFC5X7/3562778
Measuring beats guessing 1000:1
How does it measure?
In any case, it sat unused for 24 years, I'd worry more about that.
May be wrong, but think capacitor plague manifested in PC related stuff: motherboards and supplies.
Never heard about it affecting Audio stuff.
How does it measure?
In any case, it sat unused for 24 years, I'd worry more about that.
May be wrong, but think capacitor plague manifested in PC related stuff: motherboards and supplies.
Never heard about it affecting Audio stuff.
It measures fine. I should add that they were stored bagged and boxed in a cool controlled environment. As a matter of fact, I do have some caps from the affected brands - These went to the trash bin. But most are from "reputable" brands that weren't affected.
I've put some Panasonic caps from that NOS lot in my amplifier; so far so good. I give them a 24-hour "reforming" treatment - low current at close to rated voltage, as rule of thumb for this is 1-hour for each year in storage. I measure them after the treatment and they are still on spec; I even check them for heating while running the treatment. Yes I have too much time on my hands 😛 ! Still an interesting experiment though.
I won't have them in the amp for decades though. The amp is undergoing re-capping due to aging, I recap section by section and these are just a stop-gap measure while I recap the rest with fresh parts. When I'll replace the NOS caps it will be an opportunity to evaluate the effect of top-grade components in various parts of the circuit.
According to Wikipedia, the capacitor plague affected all kind of electronic products but yes, mostly PC products, since the erroneous electrolyte formulation was for low ESR capacitors. That may have saved the day for products that didn't need the lowest ESR caps.
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Thanks for this, very interesting indeed! I didn't know this form of physical branding even existed.
Mind you, those legs show some corrosion.
Not "unusable" but might not take solder well (or at all), I'd play some soft background Music and wipe a full bag worth with steel wool (not emery cloth which would remove too much) , a couple swipes between thumb and forefinger, to restore bright shiny surface.
And use these within a year.
Not "unusable" but might not take solder well (or at all), I'd play some soft background Music and wipe a full bag worth with steel wool (not emery cloth which would remove too much) , a couple swipes between thumb and forefinger, to restore bright shiny surface.
And use these within a year.
Use Scotch Brite / similar or fine (more than 600 grit) abrasive paper, try not to remove the plating, the copper underneath corrodes faster than the plating.
A brass wire brush is also quite suitable.
I would do the cleaning just before soldering.
No ties to 3M...
A brass wire brush is also quite suitable.
I would do the cleaning just before soldering.
No ties to 3M...
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Nonsense! Audiophiles have made extensive A/B listening and concluded that Mariachi music makes for a much better scrub which results in overall darker background during reproduction 😎
Jokes aside, I used to use the fine scotch brite-style abrasive pads when needed before placing components for soldering, but now I coat the pad and pin with rosin flux paste which seems to make much better finished contacts with oxyde/impirities cleaning and better thermal conduction with the iron tip during soldering.
It all depends on depth of corrosion.
Common kitchen type pot scrubbing Steel wool had no sharp edges just very fine round steel wire, very safe.
Any abrasive type cleaner: emery cloth, etc, if looked at through microscope will show sharp edges "sand". Even if very fine, it will cut through everything 🙁
To clean slight rust out of my blued guns, I wet surfaces ,with oil to soften it, wait sometime, and clean with fine steelwool under not much pressure.
It removes rust but does not damage bluing, go figure.
Any abrasive method would remove both and leave bare metal exposed 🙁
On electronic components, sometimes emery cloth is justified only when corrosion is extreme, so we need to reach bare metal, but then solder parts in place within the hour.
It will get a new protective coating: the very tin you are applying 🙂
Common kitchen type pot scrubbing Steel wool had no sharp edges just very fine round steel wire, very safe.
Any abrasive type cleaner: emery cloth, etc, if looked at through microscope will show sharp edges "sand". Even if very fine, it will cut through everything 🙁
To clean slight rust out of my blued guns, I wet surfaces ,with oil to soften it, wait sometime, and clean with fine steelwool under not much pressure.
It removes rust but does not damage bluing, go figure.
Any abrasive method would remove both and leave bare metal exposed 🙁
On electronic components, sometimes emery cloth is justified only when corrosion is extreme, so we need to reach bare metal, but then solder parts in place within the hour.
It will get a new protective coating: the very tin you are applying 🙂
You're right about abrasive, even with the fine grit pads I can expose the copper of the pins if I'm too enthusiastic on the scrub. That's why I do it only just before soldering the part. As I matter of fact I switched to using regular green kitchen scrub pads for metal chassis work !
The problem with steel wool is the mess of conductive wires it leaves behind, makes bench cleaning a nightmare and you have to watch for any bits getting on the work or chassis...
I believe there is a chemical product that turns rust into a kind of polymer for removal? The folks at tube DIY asylum use it on transformer lams.
Corroded transformer laminations will develop a gap.
That product will need to penetrate as well.
After a layer of impregnation material.
Difficult.
I would not use it before building a transformer, usually the cores are coated with anti corrosion material, if you recieve rusty cores, they should be sent back, will have excess hystreresis and so on.
That product will need to penetrate as well.
After a layer of impregnation material.
Difficult.
I would not use it before building a transformer, usually the cores are coated with anti corrosion material, if you recieve rusty cores, they should be sent back, will have excess hystreresis and so on.