# TO-5 18 39 transistors



## eastky (Dec 20, 2013)

Hello all hope everyone is doing well. Well I am still collecting scrap and studying the forum. I wanted to put this post up as an informative post. I don't have any yield numbers for gold on these type transistors. As usual I have read some post pertaining to the top hat transistors here on the forum.

I am holding a couple different styles of these right now. TO-5 TO-18 TO-39 and some 8 and 12 lead linear amplifier types I think. Been seeing a lot of these on the bay right now in lots of 50 to 100 and up. So I pulled mine out and got to doing some figuring.

The ones I have the leads are different lengths so I thought lets just even it up so I cut the leads off flush with the bottom of the package. The ones I see on the bay are different lengths. I did have a couple that had 1 and half inch long leads. So
I cut them off and weighed the leads.

Caution should be used some do contain beryllium oxide powder. Among other things thermal grease. Please be careful.

The black GE transistors may or may not contain gold. I have some that have 026 044 033 on the tops and 6230 6532
6536 on the side beside the GE symbol. I don't know if they are date codes or the part # I didn't do a search on them. Mine don't contain any gold. So be cautious when you see the black GE transistors you might buy something that's going to be a losing endeavor.

Some of the transistors will not have gold visible on the outside. You wont know until you pop the top off. Some numbers and brands that contained gold after popping them open.

RCA 2N2270 2N3053 2N5322 date codes 1982 1983 seems early 80s gold a little gold in them.

Motorola 1439G 1723CG 10 lead top hat late 70s. 2N3053 3 lead early 80s.

The list below is for transistors that have visible gold that you can see on the outside of the transistor. If the transistor is mounted on a board you should be able to look for a little gold tab on the side to tell if it will have more gold inside without removing it from the board. That comes in handy when you are looking to buy some boards but cant remove anything from them before you buy it. Just by a visual inspection looking for a gold tab will tell you.

If the transistor is a unattached transistor just look for the gold tab on the side or look at the bottom and you should be able to see gold. It doesn't have to have gold plated leads to have gold inside. Look for the gold tab. 

These numbers are top hats without leads.

TO-18 A small 3 lead package. It takes roughly 1600 of these to make 1 Pound it takes 10 to make 2.8 grams.
If these contain gold you should be able to see the little gold tab or look on the bottom and you will see a gold ring.

TO-5 it is a 3 lead package. It takes roughly 503 of these to make 1 pound. Weighs 0.9 grams each without leads.
Should be able to see gold tab or look on bottom and see gold ring.


TO-39 it is a 3 lead package. Takes roughly 411 of these to make 1 pound. Weighs in at 1.1 grams without leads
look for the gold tab or look at the bottom will be gold plated.

The next 2 are linear amplifiers I think not sure.

8 lead roughly 566 to make 1 pound no leads. Look for gold tab or gold ring on bottom

12 lead roughly 566 to make 1 pound no leads. Look for gold tab or gold ring on bottom.

I hope I haven't confused everybody that has read this post. I just want everyone to do their homework and get their own numbers. If you have some Top hat transistors that are the same style as I have check my figures by cutting the leads off a couple of each different type and weighing them. That away everyone is on the same page when it comes to a style a scrap.

Now I am going to throw something out here so everyone knows where I am coming from. I read a post on here about a style of top hat that had what I would say was a crazy unlikely yield. I am not calling anyone out here. So I don't want anyone blowing this post up with crazy replies. I want this to be a informative post so people can understand that these things aren't dripping gold. They do contain gold how much I don't know. I havent even started recovering or refining yet.
I am reading studying and absorbing all the knowledge here on the forum.

My 2 cents on the yield from a pound of TO-5 transistors. I maybe talking out my back side but here is the numbers I worked with. I had 2 TO-5s that had leads about 1 and half inches long. 3 leads per package gave me 6 leads that weighed .2dwt.

My figure for 1 pound of TO-5s is 503 without leads. I had .2 dwt for 6 leads divided that by 2 =.1dwt leads per package.

So 503 pcs = 453 grams 

.1dwt = 50.3dwt

50.3dwt = 78.22 grams

453 grams + 78.22 grams = 531 grams of material

I took 531 grams divided by 503 = 1.055 per piece.

453 divided by 1.05 = 431 pieces to make 1 pound of material.

If you were to pop open a TO-5 and smash it flat and measure how many it takes to make a square inch of area it would take at least 5 if not six. So I worked with the number 5 to be generous.

If it takes 431 to make a pound. 431 divided by 5 = 86 square inches.

Lets just say it took 503 with leads to make 1 pound 503 divided by 5 = 106 square inches


So I went to goldnscrap and hit the calculator. You can check it out yourself on the calculator.

sq inch 86
thickness 50
spot price 2000

As you can see I am being very favorable to the post I read on here about the yield from these types of transistors.
Point of view do your homework and don't be blinded from what you read.


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## goldsilverpro (Dec 20, 2013)

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=5535&p=47531&hilit=gold+transistors#p47531


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## etack (Dec 20, 2013)

I think your confusion comes from the different styles of TO-5s the ones with the great yield will look like my pic. Completely gold plated.

Eric


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## eastky (Dec 20, 2013)

goldsilverpro I read that thread. The link you posted for the TO-5 isn't working. The link not working is the one he said he had. Transistor with 3 gold leads and the gold ring. I have some of the same style transistors and I don't see that yield coming from them. Just so you know you have changed my way of thinking when looking for different types of scrap. I enjoy reading your post.

etack I am not confused. You have a TO-3 or a 66 there. I have those to but I am not jumping for joy about having them.
The weight to gold plate ratio is bad. To much base meal and not enough gold plate. Pound of those will yield low compared to the TO-5. 

goldsilverpro has opened my eyes to think different when dealing with escrap. I would rather seek out small things where I get a bigger return. Small things more precious metal recovered less chemicals used more free time to search out other profit proving scrap. Maybe I look at things differently but its in a good way.


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## macfixer01 (Dec 20, 2013)

Hi,
Thank you for the info, but just a thought... While it's nice to post brands and part numbers, it's no guarantee of any gold content. Identical parts made by the same company in different locations or at different times may or may not contain precious metals. It's best to of course save all those first with visible gold or an external gold base tab. Then I'd pop open one of each of the remaining types, if one has no PM's then those identical parts on the board with the same date code can be assumed to be the same.

macfixer01


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## goldsilverpro (Dec 21, 2013)

eastky is right, etack, those are TO3's. Like TO5's, they have been around forever. I've seen very old ones that were all gold plated but most of the ones you'll find have little, if any, gold on them. I think they are mostly diode packages. They are usually quite heavy due to a big copper heat sink inside. In general, even if the inside is gold plated, they are worth little per pound.


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