# Osciloscope



## Zhazham (Feb 19, 2022)

I got an old oscillosope with few older PC's. I'm wodering, if there are some other precious metals worth of recovering after gold and silver. After googling for a while, i end up watcing videos of refining Tantalium from capacitors. Is that worth of trying? I have never seen someone buying that.


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## MicheleM (Feb 19, 2022)

Old oscilloscopes should have Reed relays/switches , Fe-Ni alloy often plated with PM , be aware that very old relays can contain Hg inside


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## orvi (Feb 20, 2022)

Zhazham said:


> I got an old oscillosope with few older PC's. I'm wodering, if there are some other precious metals worth of recovering after gold and silver. After googling for a while, i end up watcing videos of refining Tantalium from capacitors. Is that worth of trying? I have never seen someone buying that.


Depends. Without type/photos we cannot conclude anything. If it is an old old tube oscilloscope, there is hardly anything of PM value inside, despite it weights a ton  
Maybe look the reselling price, often much more worth to sell the machine than scrap it.


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## Zhazham (Feb 20, 2022)

Luckily this is not very big. I will take better photo when i get started with it.


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## Zhazham (Feb 20, 2022)

Yes. Nothing much in there. Just few gold plated pins. That's it.


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## Findm-Keepm (Feb 20, 2022)

Probably more money to be made parting it out for the boards - I see numerous custom and scope-specific parts that others may need. Pots, ASICs, and switches can be unobtainable for older, serviceable scopes.


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## Zhazham (Feb 20, 2022)

Maybe then i better keep as it is now. Just in case somebody needs spare parts. These capacitors and chips might have some PM's but probably not enough to cover the costs of refining.


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## Hombressino (Feb 21, 2022)

With old Soviet-era oscilloscopes that could be a different story - some of them contain more than 10 g of Au and/or Pd as well. Speaking about S1-XX series, although the PM content is strongly dependent on the specific type.


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## kurtak (Feb 21, 2022)

I don't remember exactly anymore - but I seem to remember a discussion many years ago where the CRT tubes in (at least) some old oscilloscopes had a PGM coating in the tubes

Kurt


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## kurtak (Feb 21, 2022)

Just did a search use "oscilloscopes" as the search word

in this thread (2012) Geo discovered there is gold plating inside the CRT tube









oscilloscope CRT PM's


i have a couple dozen oscilloscope test fixtures to scrap. after accidentally breaking one of the CRT's from a scope, i could see the internal make up. it was porcelain with a gold coating on the inside. there were some that was silvered, and when tested, showed positive for silver. but then, i...




goldrefiningforum.com





In this thread (2020) etack points out possible Au or Pd inside the CRT tube









My first oscilloscope... but not sure on certain parts


I obtained my first oscilloscope to scrap out (non-working), and I was a tad disappointed that it's innards weren't as high-tech with IC's & boards as some I've seen from others but, in the pictures below, I marked a few components that I'm not 100% certain on and was wondering if any of y'all...




goldrefiningforum.com





Another thread from 2013 









Television Gold


Is there any PM in tv circuit boards? I am new to escrap and recycling. I am getting lots of tv boards. Does anyone have any knowledge?




goldrefiningforum.com





Geo posted ---- possibly an oscilloscope. make sure of what it is. i scrapped about a hundred oscilloscopes and a large percentage had gold plating on the inside walls of the cathode tube. only tubes that are porcelain will have a PM coating. some of them had a coating of Pd too.

those are just three of the thread I opened using search for oscilloscopes

kurt


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## MicheleM (Feb 21, 2022)

Hello @kurtak , how porcelain tubes look like? I would like to know because I have this model


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## samuel-a (Feb 21, 2022)

Yes, There's gold in them thar tubes...

It was crap to deal with though.


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## Zhazham (Feb 22, 2022)

Maybe will take A look what's inside this...


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## MicheleM (Feb 22, 2022)

Looking well to your pictures, you should check if the yellow top elements (with the cross at the center) are "trimmer potentiometer" , they could contain Ag-Pd





trimmer potentiometers at DuckDuckGo


DuckDuckGo. Privacy, Simplified.




duckduckgo.com





PDF Trimmer Potentiometers ST-32 series Nidec Copal Electronics


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## Zhazham (Feb 22, 2022)

They are potentiometers for sure but not exactly like same


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## butcher (Feb 22, 2022)

looks like,variable resistors RV##'s and variable capacitors CV##'s


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## MicheleM (Feb 22, 2022)

Yes, a trimmer potentiometer is a type of variable resistor


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## Zhazham (Mar 20, 2022)

I broke the tube. It is coated with silver looking material. I tested it with cold diluted nitric but did not get any reaction. Will heat it up tomorrow and see...


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## Alondro (Mar 20, 2022)

Those large red ceramic capacitors and the blue disc capacitors. I have a bunch of those. Do they have anything of value in them?


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## Zhazham (Mar 20, 2022)

I have no idea if these red capacitors and blue disk capacitors have any value. I would like to know too. Now i'm planning to keep these boards as is. Maybe one day have more of these to try recovery.


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## Alondro (Mar 21, 2022)

Zhazham said:


> I have no idea if these red capacitors and blue disk capacitors have any value. I would like to know too. Now i'm planning to keep these boards as is. Maybe one day have more of these to try recovery.


I also have yellows and oranges of the discs; orange, brown, green, and blue ceramic ones of many sizes. Some are easy, like the little round tantalum drop capacitors... but there are so many other types!

I've even found that some MLCCs are hidden inside the smallest blue and red rectangle ones, just before they started soldering the electrodes directly to the boards as the capacitors shrank in size. Then there are MLCCs inside glass housings on some industrial boards from the early 80's that make them superficially look like crystal diodes. THOSE appear to be all the palladium-silver type. I wish I had a TON of those boards, even if they're a pain to remove.

I wonder if anyone ever made up a sheet that has all the common capacitor types shown and what they likely have in them. 

Then there are the other types of ceramic discs that aren't capacitors: black, and glossy green and red; some with 2 prongs, some with 3. And some that are even gray. Heck, the composition might even vary drastically depending on the country that made them. 

Going back further, I have some 1st generation MLCCs from old military equipment, which looking NOTHING like modern MLCCs externally. I had to break a couple open and look at their construction to realize they were early monolithic ceramic capacitors. They were shiny black rectangles, some the size of a postage stamp.

There are literally DOZENS of types of capacitors, and even many of those have subtypes with different composition, so it gets really confusing! 

I should sort mine out into piles, and take pictures of each type of capacitor. Label them with a number. If no one has compiled a good list with clear photographs and labelling, maybe some of us should do that to help everyone out. Then we can get input on which ones are worth processing, and for which metals.

Such as this sort of listing: #23 dull brown disc ceramic capacitor, usually between X and Y cm/mm in diameter, regularly contains X metals. Then you go to picture #23 and see what they look like. Something simple and straightforward like that. If subtypes are different, you can class them numerically, such as brown discs are from #23 to #28, or 23a, 23b, 23c and so on. 

It'd be especially helpful for the tantalum capacitors, which outlandishly varied in shape, size, color, markings, and construction over the years.


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## Zhazham (Mar 26, 2022)

Zhazham said:


> I broke the tube. It is coated with silver looking material. I tested it with cold diluted nitric but did not get any reaction. Will heat it up tomorrow and see...


Overnight, coating had dissapeared and solution was clear, so quess it is silver.


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## Zhazham (Mar 26, 2022)

Alondro said:


> I also have yellows and oranges of the discs; orange, brown, green, and blue ceramic ones of many sizes. Some are easy, like the little round tantalum drop capacitors... but there are so many other types!
> 
> I've even found that some MLCCs are hidden inside the smallest blue and red rectangle ones, just before they started soldering the electrodes directly to the boards as the capacitors shrank in size. Then there are MLCCs inside glass housings on some industrial boards from the early 80's that make them superficially look like crystal diodes. THOSE appear to be all the palladium-silver type. I wish I had a TON of those boards, even if they're a pain to remove.
> 
> ...


Just another day, i saw post classifying different types of capacitors here. If i find it again, i will link here.


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## Alondro (Mar 27, 2022)

Zhazham said:


> Just another day, i saw post classifying different types of capacitors here. If i find it again, i will link here.


I'll look too.

EDIT: I think I found it: Do any of these components contain Palladium?

Looks like it's best to just test them, there is so much variety even by country. But the disc types seem to at least contain silver. If it be confirmed that they are older than 1995, they probably also have Pd. 

Other types I still don't know about. Stuff from the USSR appears to have incredible yields.


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## macfixer01 (Apr 13, 2022)

Not all oscilloscopes are the same quality. Tektronix scopes and analyzers are very good and will often have gold plated boards, lots of socketed gold lead transistors, and specialized gold plated IC’s. Another thing they did a lot was using cams to press down different combinations of many gold plated contacts to gold plated pads on the circuit board when switching settings from knobs on the front panel. The really old Tek scopes were tube based and they used white ceramic bars as attachment points for discrete components. Those type may still have a small roll of extra silver solder left inside for doing repairs. HP and Agilent scopes and analyzers are also pretty good, and better than most other brands.

Many of the Tektronix scopes used a CRT that’s partially ceramic, both for stability and because it allowed adding extra deflection elements coated on the inside surface for a higher beam acceleration. The neck portion where the electron gun and grids are is clear glass, then the main body is ceramic, and the front plate with the phosphor coating is thick leaded glass. There is an old promotional video on YouTube showing how the Tek CRT’s are made, and in there it says the coating is a combination of gold and palladium. It’s painted on during manufacturing and then fired in a kiln. After that they actually grind it away in areas where they want separation between the different bands.

These are some Tektronix CRT’s I have collected. They already have the clear glass necks broken off of them.


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## macfixer01 (Apr 13, 2022)

Here is the old video I mentioned that shows the Tektronix CRT’s being manufactured. The section that talks about the internal coating starts somewhere around the 19:30 minute mark.


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## markscomp (Apr 16, 2022)

that was very interesting - like an old fashioned disney movie for geeks and scrappers alike
Mark


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