If I could bring myself to use mercury vapor tubes at all, I'd be damn tempted to use these ones.. 10KV PIV, 5A peak current / 1.25A constant current.. 5V @ 7.5A filament, but that's not a big deal to me.
Found this youtube video of a guy using them https://youtu.be/GJp4LbBQX14
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Yea.. I'd likely use them more for their looks as well
There's nothing wrong with that in my opinion. Though I was recently dreaming about building some big beastly 212E monoblocks (after I realized that Psvane makes these tubes now).. With the power supply I was simulating, I was closing in on that 5.5KV PIV number that my beloved 6CJ3 tubes are rated for.. So that 10KV rating is also enticing, as well as that peak current rating..
Good god would that end up being an expensive pair of monoblocks to build though. I'd likely have to enclose the whole power supply including rectifier tubes inside a closed chassis, likely some sort of massive upright chassis. maybe with a window to see the pretty blue glow of the 872A's though.
I wonder where you could get a big chassis like this made.. Likely a lot of custom very expensive work at a machine shop.
Yea.. I'd likely use them more for their looks as well
Though I was recently dreaming about building some big beastly 212E monoblocks (after I realized that Psvane makes these tubes now).. With the power supply I was simulating, I was closing in on that 5.5KV PIV number that my beloved 6CJ3 tubes are rated for.. So that 10KV rating is also enticing, as well as that peak current rating..
Good god would that end up being an expensive pair of monoblocks to build though. I'd likely have to enclose the whole power supply including rectifier tubes inside a closed chassis, likely some sort of massive upright chassis. maybe with a window to see the pretty blue glow of the 872A's though.
I wonder where you could get a big chassis like this made.. Likely a lot of custom very expensive work at a machine shop.
Those chassis would be simple to make. The sides are just aluminum "C" channel and the face is just plate. You could make them with a hand drill and hacksaw.
Yep, I seem to drop everything and my wife would kill me if I contaminated the house......just for the sake of art.
I wouldn't consider Hg vapour diodes. The advantage to these is a low forward drop that's consistent across varying load currents for better voltage regulation. Si diodes do the same and do it better: no need for extra holes, no filament power, much lower forward voltage drops, much higher Isurge capabilities, no negative resistance characteristic of glow discharges that lead to RF noise, and if you drop a Si diode on a concrete floor, no need to call the HazMat specialists to clean up the mess.
The one and only down side is no glowey bottle coolness.
I hate that this is the primary reason I'm still drawn to tube rectifiers..
On this note though, I did have trouble finding Si diodes that have >5KV PIV ratings last time I looked.. Unless I'm not searching on digikey or mouser correctly.. What diodes do you use for this application?
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Quick kind of off topic question... when my dad passed away a few years ago I inherited some odd junk he'd carried around for a long time. One item being an old mercury switch. It's about 1" long and 1/2" dia. pretty good quantity of mercury sloshing around inside. No idea how old, but going by the wires on the switch I'd guess 1940's. How does one dispose of something like this?
C'moon guys .Just to think of all the mercury in old thermostats and fluorescent lamps which are broken in the households. Your not going to save the planet with your miserable "green" attempts nor live much longer avoiding all the risks. Some virus will get you faster than mercury poisoning ever will . Have some fun.
Your city's waste management should have a safe and free drop off for these. Old thermostats used mercury and my local Ace/True Value hardware store accepts them for recycling.
To Kevinkr's point surely it would help if somebody told us way in the past that breaking up for fun hundreds of fluorescent bulbs and playing with mercury from huge thermometers and other devices sourced in local agricultural labs waste bins was not in our best interest...I remember that each of us had a small jar full of mercury and it was a contest among us , who will collect more of it .Not sure how I survived my crazy youth
That may just depend on the transformer. Some may work up to the rated current and some not.
You want a turn on delay for the plate supply. 3b28s want just 10 seconds. They get unhappy if you apply plate voltage right away. The delay can be done easily with a dc relay and some circuit that has some resistance before a cap across the relay..
Are you using a choke input supply? A cap input supply will be a bit noisy and choke input less noisy.
You need to be prepared for switching noise. The tube needs to have the 50 critical volts across it before it starts to conduct. It will conduct to somewhere below 14 volts once it starts. It will do this each cycle.
Also it seems there are some versions that hide the wonderful purple glow. Be careful what you buy. Most have a nice visible gap between cathode and plate and you can see all of the glow. One the other hand, someone decided to hide that in one variation.
You want a turn on delay for the plate supply. 3b28s want just 10 seconds. They get unhappy if you apply plate voltage right away. The delay can be done easily with a dc relay and some circuit that has some resistance before a cap across the relay..
Are you using a choke input supply? A cap input supply will be a bit noisy and choke input less noisy.
You need to be prepared for switching noise. The tube needs to have the 50 critical volts across it before it starts to conduct. It will conduct to somewhere below 14 volts once it starts. It will do this each cycle.
Also it seems there are some versions that hide the wonderful purple glow. Be careful what you buy. Most have a nice visible gap between cathode and plate and you can see all of the glow. One the other hand, someone decided to hide that in one variation.
High school chemistry class had a large jar of mercury; for some reason I refused to handle it figuring the stuff was toxic. Other than eating a lot of tuna as a kid, I've had relatively limited exposure to mercury. I've also had some really serious health problems at various points in my life that in some cases had a environmental causation.
I'd be concerned that the filament transformer is a bit small for the intended load.
As an aside I've heard it said by some that the 3B28 doesn't sound as good as the equivalent MV rectifier. (872?)
I'd be concerned that the filament transformer is a bit small for the intended load.
As an aside I've heard it said by some that the 3B28 doesn't sound as good as the equivalent MV rectifier. (872?)
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