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Hi!
Buying old electronic equipment, is also buying old toxic hazards.
Cadmium, just to name one, was quite common anti-oxidant coating on steel, in old equipment.
And, I have seen many people that have bought some old gear.
Then, started to scrape or steelbrush that white cadmium crud off, without any thought of the consequences.
One thing I wonder about is, when buying stuff off that "e" version of pirate bay, where does all this old stuff come from?
If it originates from Ukraine, the first thing that comes to my mind is Chernobyl.
Everything that was welded, bolted or in any other way removable, has been removed from that town, and sold.
Same thing with Russian equipment - "came from a decommissioned sub".
Yes, it probably was a atomic one.
So, can tubes be radioactive?
Follow Ups:
Thank you for your answers in this thread!
It is just when you see a picture like this, and realize that every vehicle has been looted, and re-looted many times, and everything possible have been removed, and sold.
Sold on local flea markets, maybe.
Exportation requires that parcels are scanned (for radioactivity as well) several times.
Plus, this is a military scrap yard, even to process this metal one needs special permits.
There is a huge difference between this scrap and NOS stuff from warehouses that might be decommissioned as not necessary spares. Just think of all the JAN tubes...
******
http://rh-amps.blogspot.com/
Having had professional experience with scrap metal and recycling, as well as ecological legal requirements (governing laws), I would regard as highly unlikely that one might be able to buy (OK, scams are possible) and more importantly have the goods delivered to ANY "civilized" country in the world (no offence intended), and particularly in Europe: I guess the US/Canada part of the world is at least as restrictive and vigilant.
The first issue would be decommissioned military stuff: even if allowed for trade at all, it would pass under several radiation detectors in several points along the way, and it is almost unbelievable it might reach the final destination if radioactive.
People in the West seem to be still fascinated with Soviet or Russian military stuff (the less knowledge and experience, the more one is prone to fascination) so many items are marketed as decommissioned "from a sub" or similarly. In reality, what one can buy might eventually be decommissioned from some military warehouse, where it laid dormant for decades, or is even NOS items.
Some stuff is even misrepresented as being military or having had some role - like GM70 tubes having been used in Soviet tanks (?!?) or being military items built like a tank. I've seen a fair quantity of those with perfect getters (intact vacuum, never used) and broken filaments due to mishandling: hardly anything to use in a tank!
******
http://rh-amps.blogspot.com/
Most Geiger counters you can buy were made for atomic fall out measuring, so very unsensitive, and not suited for detecting low level of radiation. I was lucky to find a very sensitive laboratry probe for fluids, which is very sensitive in air also.
I bougt it after Fukushima, just to make sure I get no contaminated shipments from Japan. I never found anything whatsoever. So I have this unemployed Geiger counter here. What to do with it.
You need to understand the introduction, I will come to the tubes in the end.
I started checking the house and the garden. I found indeed some sources of radiation. For instance the red granite stones in my garden, they produce something. Some tiles in the house, and also some of the gypsum walls. How much it was? I can't tell, but it was at the limit of what the instrument can do, and I counted (with my Iphone) the ticks over 30 minutes of more, in order to see the difference with natural radiation coming from space and from the ground. So really very very little, and when you go further away as 3cm from whatever object, there is nothing detectable any more. All you hear is cosmic radiation ticking.
When checking some of the food, I was shocked. I was able to detect increased radio activity on a bag of dried mushrooms, my wife uses for cooking. It was really a lot. No need to count 30 minutes. Just hold the probe inside the bag, and I could hear more ticks than normal. That was the only alarming thing I ever found.
Now come the tubes. I have many of them, all kind of. So I took a box of 1945 made 211 tubes (thorium cathodes....) Guess what? A whole box of tubes produced nothing detectable whatsoever. I took a whole box with VR105 Voltage regulators. I burried the probe all inside. These contain radioactive Xenon gas. They say. Also no reaction whatsoever. I removed the heaters from a broken 845 tubes. Extremely carefully not to breath any dust. I held the probe right on them. Also no reaction whatsoever, but here the mass was not enough to my impression. Too tiny sample. But fair enough, inside a 211 is not more than that also.
So can tubes be radioactive? If you take cosmic radiation as a reference, my answer is no. Dried Mushrooms radiate more than 211 or VR105 tubes.
Jac
I'd be more concerned with breaking Hg-vapor rectifiers.
Jim J.
Hi,
Some tubes can have doped cathodes, like certain gas regulators for military or industrial use, the added emissivity of the dopant will allow those types to ignite even in complete darkness.
Almost any tube that has a radioactive element in it will be either an alpha or beta emitter, and neither type of radiation will escape the glass envelope.
Whether something has been exposed to a contaminated area and has particulate contamination (like from Chernobyl) on its surface is another matter entirely. I wouldn't rate that as terribly likely.
The only other thing you have to worry about is circuits that employ vacuum tubes at voltages over say, 10Kv, where you start to get some X-rays produced, but that is only a problem while the circuit is on.
Bottom line is that unless you break open a tube, you have very little to worry about. Most if not all audio tubes will be free of any radio-isotopes, but may very well have heavy metals present inside. If you break a tube, clean up carefully, avoid breathing any dust, and all will be fine. Be extra cautious if you bust open a military gas regulator, you DO NOT wish to inhale any particles of alpha emitter. That could be very bad.
-SF
Radioactive (dht)
Yes, thorium is radioactive. It's an α emitter with a very long half life. It's the decay products of thorium that are "problem children".
Eli D.
also used in coleman lamp mantles for many years.
for an interesting account read or google The Radioactive Boy Scout. Guy actually built a reactor in.his back yard.
It would probably take a billion years or so for it to become dangerous to you sitting in your amp.
Nobody here at least :-)
Well, everything is radioactive, that is, gives up part of its atomic structure/particles over time. Only a Geiger counter will tell you how much. If you are really concerned you should get one. Since tubes work by emitting electrons they radiate more than other electronic devices so you should not let your children have their play time where your tube amps are operating. regards, Dak
Electrons emitted by a tube cathode (cathode rays) are a form of "radiation", but they are not "radioactive". In other words, cathode rays are not known to be particularly dangerous because they don't carry enough energy to be ionizing (aka radioactive). So it's safe for your children to be around your tube gear. Unless they grab a hot tube or somehow shock themseleves.
Tubes can be radioactive, but probably not in the way you are thinking about it.
Voltage regulator tubes typically were purposely made with a tiny amount of radioactive material inside. The idea was to provide an ionization source to help trigger the things to conduct.
Some materials used in tubes contain some naturally radioactive isotopes. Thorium, for example.
Exposing material to radioactive bombardment doesn't usually result in that material becoming radioactive itself. Usually the matreial has to be contaminated with some of the radioactive compounds.
As far as recent production tubes possibly using contaminated recycled material ... Well, who knows? Get your Geiger counter out and see. However, you might have to break the envelope to find out - The glass will block virtually all radioactive emisisons from the electrodes inside.
are older triode transmission tubes. i have several with green doped glass around grid and plate leads. the glass is doped with uranium oxide prevent ionizing effects of extremely high voltage from breaking down the glass seals.
East Tennessee? Oak Ridge perhaps? Which would explain your knowledge of radioactivity.
Ha! Bingo! Oak Ridge it is. I'm not a scientist or physicist, but I worked with them a number of times and this stuff just rubs off on you if you pay attention.
I'm actually a software developer. The closet I came to needing real knowledge of radioactive decay, etc. was a project I worked on for a manufacturer of medical isotpes. I had to write a module that hooked into their MRP (manufacturing) system. It determined how much total "activity" was on their property at any given time so that they could prove to NRC regulators that they were within licensed limits. This presented an interesting problem because most of the material they handled had extremely short half-lives. However much activity was onsite at one moment was quite different than an hour later. And the amount of each element changed because some of each element decayed into another element with a different half-life. Talk about a moving target!
I went to UT in Knoxville and had friends whose parents worked in Oak Ridge in the "old days". Lots of interesting history and an absolutely beautiful part of the country.... I call it little Ireland. I can't tell you what fond memories of the many leisurely hours that only a college student has on those incredible TVA lakes. I know, I'll shut up... don't want to get that secret out of the bag.
Go Vols
The radioactive material used in gas discharge regulator tubes is a β emitting Ni isotope, which turns into stable Cu. No truly dangerous γ radiation is present.
Damned clever those old engineers.
Eli D.
Also, beta particles wouldn't make it through the glass wall.
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