Liquid mercury drops can be neutralized by sulphur powder, if I remember correctly. At least small spills from broken thermometers. Mercury vapour is a different thing.
They are potentially dangerous, if attractive, dinosaurs that were passed by in the eyes of history to more practical solutions. We have nearly a century of tubes to choose from, so might as well pick a better dinosaur 🙂
That blue glow is pretty, but very bad for your eyes. I wouldn't operate theses in plain view for various safety reasons.
I've only used one MV. It was a type 82. Being one of the smallest MV rectifiers it didn't seem to put out a lot of UV, but then again I wasn't drawing much current. I had one of them drop and shatter, but it was inside it's box and wasn't a big deal to clean up (like if it had been running).
On Earth, everything is dangerous, crossing the road and even the words that came out from one's mouth! I'm now 76 yrs, don't wear glasses, and have been using from 816 to 866 to DCG4/1000 for years without problem. Don't let those professor scare you off!
Zekk
That's a GEC designed Williamson, using L63 > 6SN7 > GE 6550A > A431 OPT. Operating at 450v@280mA. More current passing thru, more greenish.
I’ve used them for a long time. I don’t stare at them so maybe that’s the difference.
Have most every QST magazine from the early 30’s to the late 60’s.
I’ve read most every one and don’t recall any issues with using them.
Common sense goes a long way.
Just my 2 cents
Have most every QST magazine from the early 30’s to the late 60’s.
I’ve read most every one and don’t recall any issues with using them.
Common sense goes a long way.
Just my 2 cents
We use UV irradiators to cure (Crosslink) plastic resins incorporated with photo-polymers. Much faster than thermal radiation. Every year we have a training session for the line employees on "what to do" if someone drops one of these bulbs -- much of the world is going to UV-LED's.
A mercury vapor radiator can cause severe eye damage in very short order.
I have a I-177B Tube Tester which uses the 83 tube for it's rectifier.
I'm wondering if a pair of rectifier diodes followed by a pair of 15V zeners would make a suitable replacement?
The tube datasheet states the approximate voltage drop is 15V, 17V absolute.
The one issue I see is the drop in filament load for the 83, so voltages will be higher. It might be possible to compensate for this with the Line Test adjustment
Years ago I had a pair of 866s. I turned them in to the local hazardous waste facility along with a pound bottle of mercury I had from childhood. Best to have it properly disposed of.
I'm wondering if a pair of rectifier diodes followed by a pair of 15V zeners would make a suitable replacement?
The tube datasheet states the approximate voltage drop is 15V, 17V absolute.
The one issue I see is the drop in filament load for the 83, so voltages will be higher. It might be possible to compensate for this with the Line Test adjustment
Years ago I had a pair of 866s. I turned them in to the local hazardous waste facility along with a pound bottle of mercury I had from childhood. Best to have it properly disposed of.
As a kid in the 60's I had a whole jar of mercury, my uncles would give me thermometers, wall thermostats, Mercury switches, etc because they knew I liked to play with mercury. They also gave me all their old tv's and radios because they knew I liked to dismantle them. My dad and I would roll mercury around in a cardboard box at the kitchen table to watch the globules split. Who knew it was harmful? I never suffered any form of mad hatter disease, at 64 I'm in excellent health. I'd say run some breadboarding experiments with the tubes just to satisfy the insatiable curiosity engineers are obsessed with. Use the tubes as a science experiment. Then heed the doctors by not actually making an amp where some future unsuspecting owner buys it from your estate sale after your dead and breaks the tube. Over the years I've broken several CFLs in my home that got cleaned up like any other broken bulb, a vacuum cleaner and wet rag, with no ill effects so far.
The supply chain behind a CFL bulb is huge, all the way to mining, chemistry, and all the supply chains behind the components. An Edison bulb has 4 or 5 primitive parts, little chemistry, little mining just the tungsten, no resistors, capacitors, silicon, etc each of which has a deep and expensive supply chain. Edison bulbs have no environmental issues, and with short simple supply chains use little energy to make. Edison bulbs do use more energy in use, but that savings is decreased by the deep complex supply and mfg chain differences to CFL. So there are many arguments in favor of keeping incandescents around for a while yet.
normal glass will block uv.
mouthful of amalgam, still alive..it has best mechanical properties
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Me too 🙄. I also severely doubt that an acceleration voltage of solely about 15 V may give the electrons that much kinetic energy that they can release emission in the UV range from the Hg ions.
Best regards!
Best regards!
Early type 866 produces very high energy short wavelength UV; later type 866a has a screen around the anodes. Still, don't stare at them, it's not polite.
All good fortune,
Chris
All good fortune,
Chris
UV LED have forward voltage drops of 5-6 V. 15 V is more than enough energy to produce a UV photon under proper circumstances.
If you want to do the math, photon wavelength = h*c/E = 82 nm for 15V electrons. Well into the ultraviolet.
JS