# capacitors



## glondor (Jan 28, 2011)

I recently made a purchase of tophat transistors and I C's. 140 pounds of them...It was a very mixed lot, but it was very cheap. After sorting I had 5 pounds of these...






and 2.5 pounds of these...






Now what I found interesting were these...(bottom right)






I checked them with 14k testing acid and there was no reaction. I then checked them with 22 k acid and after about a minute or so there was a bit of green bubbling and the acid had gold foils on the meniscus of the drop. 

I did not think that gold caps existed. Am I in error here some how?

As a by product of my purchase I have lots of plain tophat transistors as well as many pounds of IC'c and eproms. General question, could they have values? I suppose they could, and I have lopped off the top of a few tophats and all i see is a very small silverish chip. Would these be too much of a crap shoot to do anything with???


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## goldsilverpro (Jan 28, 2011)

The first photo is TO3s. Probably, only the ones where gold is visible have any gold value. You can pop a few of the others open to see if anything is in them. The TO3s, even with gold on them, are the least valuable per pound, by far.

The parts of greatest value in the second photo are the TO5 "top-hat" transistors with visible gold on the bottom and around the rim of the header.

We used to call the parts in the 3rd photo, PLEs. Don't ask me why. They are less valuable than the TO5s.

TO5s - Most valuable, per pound
PLEs - Intermediate value
TO3s - least valuable


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## glondor (Jan 28, 2011)

Thanks GSP. I did refer to the post about the tophats, just missed the part about the caps. Is there pm's inside them as well?


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## texan (Jan 29, 2011)

glondor said:


> Thanks GSP. I did refer to the post about the tophats, just missed the part about the caps. Is there pm's inside them as well?



The six items in right of the bottom photo are power transistors and not capcitors.

Texan


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## qst42know (Jan 30, 2011)

I don't see a capacitor in the whole bunch however I would like to see what you end up with.


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## glondor (Feb 22, 2011)

Does any one have a recommendation on how to open the top hat transistors shown in the photo above. I understand there is values inside as well and I am curious how to get to them in the best manner possible.

I believe I would try to melt the solder, and drop the solder off however I am not sure this is the right approach. Do they pop when they are heated?

Once I get them open I will try them with poor mans nitric unless some one can recommend a better way.


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## FrugalEE (Feb 22, 2011)

Search for thread 3golden legs transistors. Read GSP's post. He recommends using dull side cuttors to open.


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## glondor (Feb 22, 2011)

Thanks FrugalEE. I did read that post. I understood that the side cutters are a good way to pop open the little ones. I may have to try bolt cutters for the larger ones. I am wondering if any one has a faster way that has worked for them rather than opening each one individually. A hammer mill comes to mind but I don't have one of those.

Maybe I should just slow down and do them 1 by 1. :lol:


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## FrugalEE (Feb 22, 2011)

By little ones I'll bet you mean both the TO18 smallest, and the less than 1/2 inch diameter TO5. I expect your real problem is the larger power transistors. I would start with a very sharp chisel and try to get the lid to pop off. You probably need to specially grind a cold chisel or old wood chisel. You cold use a normal bench grinder, but that makes a mess. I would concentrate on opening one of each different looking part and look for gold inside. I"ve got some old power transistors. I'll change into my old clothes and have a go at opening up some.

FrugalEE


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## FrugalEE (Feb 22, 2011)

Clamp the top hat part of the power transistor in a vise and keep turning until is bunches up and tears loose around the edges. Then pry up with a screwdriver or chisel. I notice that some devices have the flange recessed making it difficult to chisel open the seam.


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## FrugalEE (Feb 22, 2011)

Glondor,

Attached is a photo of three old transistors I opened using vise at two angles 90 degrees apart along with a bit of prying.

The device at left is an old RCA germanium device which is rather crudly built and doesn't have any etched finger structure - OH NO, I just destroyed an antique! That device had white chemical in it which I presume is to absorb moisture.

The middle device has been blown and I think that must be the source of the very thin gold flash as otherwise it makes no sense to be there.

The piece on the right is by far the best one, but the middle one has some gold and I can't find any on the left one. I would use sulphuric cell, at least for the first go at it as there is a lot of base metal to deal with otherwise. To recover the gold solder under the chips you need to check with the Pros like GSP or Lazer Steve. Both have already posted info on dealing with soldered chips. For these transistors I really didn't see any significant gold solder used under chip.

Have fun,
Frugal


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## glondor (Feb 22, 2011)

Thanks FrugalEE. I appreciate you taking the time to check these out for me. I have been sorting them all afternoon. I will let you know how I progress.


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## lunker (Feb 22, 2011)

Glondor,
pinch the bottoms with a pair of vice grips and squeese and twist with a pair of side cutters. You will find that the steel covers tear away from the bottoms fairly clean. You can then strip them with AP etc. 
FrugalEE, 
I have received the DMG. again I am ever gratful.Thank you.
I will try and get to testing the cap solution this week!


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