Russian Capacitors..

Bernardduur · Post by **Bernardduur** » 31 Jul 2010, 08:31

Those russian caps are not paper in oil; I have a few and they are just poly's

IvIark · Post by **IvIark** » 31 Jul 2010, 11:44

Bernardduur wrote:Those russian caps are not paper in oil; I have a few and they are just poly's

They are. They're K40Y-9 (the silver one) and K42Y-2 (the green one). The poly (PETP) Russian axial caps are K73-** this these:

or these:

Greg · Post by **Greg** » 31 Jul 2010, 13:55

IvIark wrote:
Bernardduur wrote:Those russian caps are not paper in oil; I have a few and they are just poly's
They are. They're K40Y-9 (the silver one) and K42Y-2 (the green one). The poly (PETP) Russian axial caps are K73-** this these:

Unfortunately I have to say Bernardduur's right.. they're not.

I have a couple of boxes of them (K40 & K42), bought off Ebay in the belief they were PIO as advertised and claimed everywhere.
So.. I went down to my workshop tonight and dissected one from each box...

*EDIT*.. sorry, I stand corrected.. I had to go out half way through dissecting the K40 and I made an assumption based on what I could see.. I was wrong and it turns out that the K40's are PIO.
The K42's aren't.

I have to say they're bloody tough though.. the cases are thick and I suspect they're stainless steel.
The toughest cases I've ever found on a capacitor.. must have been designed for use in Tanks or something.

IvIark · Post by **IvIark** » 31 Jul 2010, 15:17

The K42Y-2 is supposed to be aluminium foil with an oil impregnated paper dielectric, and I've got one open in front of me and it looks to me like that is a fair description of what I'm seeing. I'm not going to have chance to lab test the paper for oil, but I don't see much reason why the spec sheet would be inaccurate.

Greg · Post by **Greg** » 31 Jul 2010, 16:30

The dielectric in the K40 is brown and oily paper..
..in the K42 I opened it's transparent and completely dry film ... there's no sign of oil and it's not paper.
I can post pics if you like.

The oil in a PIO cap should be pretty obvious to the touch (and smell).

IvIark · Post by **IvIark** » 31 Jul 2010, 17:49

Isn't transparent what you could possibly expect if paper was impregnated with oil? That's how they used to make tracing paper and that was dry too. Is there any information anywhere that suggests that it they have to be dripping wet if they are oil impregnated rather than oil filled?

It wouldn't make much sense for a manufacturer to lie about one type of capacitor and tell the truth about the others. It's not like they were making these in 1980s Russia for mojo purposes. And these would be unbelievably good fakes considering I bought them along with K40s and they all came individually in the same style sealed manufacturers boxes.

But admittedly I'm not an expert in what does or doesn't make a paper in oil capacitor, and I'm definitely open to guidance from anyone who is an expert in them, or their manufacturing processes.

IvIark · Post by **IvIark** » 31 Jul 2010, 18:24

I'd only cut the top off so just pulled the rest of it apart and this is what I ended up with. This is a 100nF K42:

neiloler · Post by **neiloler** » 31 Jul 2010, 22:13

What did you open that can with?

IvIark · Post by **IvIark** » 31 Jul 2010, 23:12

That's just the aluminium foil. I cut the cap at one end with pliers and then squeezed with pliers from the other end to push the guts out. They are really tough cases, at one end the pliers just didn't want to go through which is why I ended up squeezing it out.

Bernardduur · Post by **Bernardduur** » 01 Aug 2010, 08:21

Greg_G wrote:The dielectric in the K40 is brown and oily paper..
..in the K42 I opened it's transparent and completely dry film ... there's no sign of oil and it's not paper.
I can post pics if you like.

The oil in a PIO cap should be pretty obvious to the touch (and smell).

Ah, great! I have both

SPeter · Post by **SPeter** » 01 Aug 2010, 16:43

IvIark wrote:The K42Y-2 is supposed to be aluminium foil with an oil impregnated paper dielectric, and I've got one open in front of me and it looks to me like that is a fair description of what I'm seeing. I'm not going to have chance to lab test the paper for oil, but I don't see much reason why the spec sheet would be inaccurate.

+1! Found a site with description! It's a metal/paper cap as I can read it!
http://www.electroclub.info/other/conders2.htm

Greg · Post by **Greg** » 02 Aug 2010, 00:58

IvIark wrote:The K42Y-2 is supposed to be aluminium foil with an oil impregnated paper dielectric, and I've got one open in front of me and it looks to me like that is a fair description of what I'm seeing. I'm not going to have chance to lab test the paper for oil, but I don't see much reason why the spec sheet would be inaccurate.

Can you point me in the direction of that spec sheet please IvIark.

I haven't been able to find anything I'd consider to be definitive specs for the K42 caps... mostly just audiophiles banging on about them, and strangely the general opinion seems to be that the K40's are great and comparible to Vitamin Q style caps, but the K42's aren't as good..
If they were both PIO, you'd have to wonder why they consider one better than the other ?

The one you opened and photoed does look like it is PIO to me, but I still don't believe the one I opened up is.. more likely Metallized Paper I think.
Possibly some K42's are PIO and some aren't depending on the rest of the part number ?

I'll take a couple of photos of the ones I opened when I get a few minutes.

BTW - I did find this.. by no means definitive, but seeming to agree with what I found:

K31, SSG, SGM, KSO - mica, some types with silver - good
K40 - PIO - very good
MBGxx, KBG-xx, OMBG - PIO
K42, MBM, BM-x - paper (w/o oil ??)
K70, K71 - Polystyren ("polystirol") - good
K72, FT - teflon ("ftoroplast") - THE BEST
K73 - Polythelene Teraphthalate film ("lavsan") - poor
K75 - combined Paper+Film (Polythelene Teraphthalate??, with or w/o oil??)
K76 - Laquer film
K78 - Polypropilen

IvIark · Post by **IvIark** » 02 Aug 2010, 07:56

I'd say that actually agreed with what I found, you said yours weren't paper. And if the K42s are oil impregnated paper rather than oil filled then I don't suppose it's too surprising that someone else is questioning whether or not it has oil, in much the same way we are here. But someone else describes them as metalized paper PIO in the same thread.

The K40s and K42s have been discontinued a while now so they aren't in the manufacturers current catalogue, but there were datasheets in the boxes so I'll find them and do a scan.

So erm ... the Gas FX Drive Thru

Greg · Post by **Greg** » 02 Aug 2010, 08:19

IvIark wrote:I'd say that actually agreed with what I found, you said yours weren't paper. And if the K42s are oil impregnated paper rather than oil filled then I don't suppose it's too surprising that someone else is questioning whether or not it has oil, in much the same way we are here. But someone else describes them as metalized paper PIO in the same thread.

The K40s and K42s have been discontinued a while now so they aren't in the manufacturers current catalogue, but there were datasheets in the boxes so I'll find them and do a scan.

So erm ... the Gas FX Drive Thru

I did say that, so I guess I was wrong.. but I also said I did it all in a bit of a hurry.

If you look down this page (Russian Export page), it also refers to K42's as Metallized Paper. http://www.allsiberia.com/novosibirsk/B ... citor.html

Metallized paper is metal deposited on paper, and doesn't involve oil AFAIK, and again the one I opened couldn't be much drier... I see no sign of oil, wax or anything else like that. The layers came away easily, not sticky like PIOs.
PIO is oiled paper layered with metal foil.

"Metallized Paper Capacitors: A modification of a paper capacitor in which metal foils are replaced by extremely thin films of metal deposited on the paper."

I'll move all the cap posts to a new thread.

IvIark · Post by **IvIark** » 02 Aug 2010, 09:06

That page says K42-19, not K42Y-2 or K42U-2. In the manufacturers current catalogue it gives details of the K75 capacitors which you see for sale on eBay and there are about 30 different types of K75 capacitor. Some with metallized film, some foil, some with paper dielectrics, some with film. So I don't think we can take the characteristics of a different model by the same manufacturer as any indication of what may or may not be in the capacitor we're discussing.

To be honest though Greg it's almost getting to semantics. I've opened one up and to me it looks exactly what I've seen it described as, oil impregnated paper. It's not wet, but it does feel a bit greasy but that's something hard for me to quantify because the dielectric is quite small and I don't know how much of what I can feel is oils from my fingers. I don't have any sense of smell so that doesn't help me, I can't smell anything with the K40 either. For all I know paper could be just as good or better than PIO, I don't know what advantage adding oil to the dielectric gives you. In fact I've got more K40s than anything so it'd be quite useful for me if these were just paper without oil because they'd be something different for comparison. So I'm not saying this from a point of mojo, I'm just saying what I see.

Greg · Post by **Greg** » 02 Aug 2010, 09:26

For sure..

Just for reference, I just checked and the one I opened was a K42Y-2 also.

The K40 I opened had oily brown paper rolled between foil, and from the pic your K42 looks similar in construction to that, but my K42 is different.

Whether there's any difference between them goes back to the old question of whether different cap types sound different in effects too.. the jury's still out on that one for me.

Greg · Post by **Greg** » 04 Aug 2010, 05:43

OK..
I finally had some time to take a good look at these caps and take a photo.

I may have been hasty to judge them, as it looks like the K42 might be some form of waxed paper cap. When I tried before I couldn't separate the layers, but with some magnifying glasses and care it looks like they can be separated.
Again they still seem very dry as opposed to the K42 which is clearly oily and a different colour, and which separates easily.

So, here's the ones I dissected.. K42 and guts at the top, and K40 and guts below (click on it for a clearer pic).