I have some mercury rectifiers that I have not planned on using. But I am tinkering with the idea of a 'show off' amp just for demonstrating the fascinating side of tubes, and tube glow is a part of that.
One set I thought of using is a pair of Philips DCG/1000-01. But I cannot find any data on filament voltage and current.
I do find the DCG4/1000, this has 2.5V/4.8A filaments. So can I assume DCG/1000-01 is 2.5V but only 1A?
Any one here know?
As for using mercury rectifiers. I know some of the risks, probably not all, I know one must apply heater power long before HT (at least 1 minute?). Is there a tell tale way of knowing when one of these are bad, and even if they may catastrophically self destruct?
If I want to dispose of them, where do I drop them off? I guess the local dump has 'dangerous goods' section and will send them to where they belong. I dont intend on selling them, just because I dont like poison going to who knows where...
Or am I over reacting?
thnx for comments
One set I thought of using is a pair of Philips DCG/1000-01. But I cannot find any data on filament voltage and current.
I do find the DCG4/1000, this has 2.5V/4.8A filaments. So can I assume DCG/1000-01 is 2.5V but only 1A?
Any one here know?
As for using mercury rectifiers. I know some of the risks, probably not all, I know one must apply heater power long before HT (at least 1 minute?). Is there a tell tale way of knowing when one of these are bad, and even if they may catastrophically self destruct?
If I want to dispose of them, where do I drop them off? I guess the local dump has 'dangerous goods' section and will send them to where they belong. I dont intend on selling them, just because I dont like poison going to who knows where...
Or am I over reacting?
thnx for comments
The last Mercury rectifiers I saw used were in a protective enclosure in a different room than the amplifier. That was to reduce noise. Places that recycle fluorescent lamps should be able to recycle them.
I can’t imagine how you would clean up after an explosive failure.
I can’t imagine how you would clean up after an explosive failure.
Mercury vapor=nerve poison --vaporizes at room temperature--easily inhaled-absorbed into the blood stream --agitation-paralysis .
History--- hat makers in old England used mercury in their work ---hence the saying "as mad as a Hatter " -banned in the EU -German neurologist/toxicologist -Thomas Gebel --causes erethism mercurialis and if that doesn't worry you it makes males infertile.
History--- hat makers in old England used mercury in their work ---hence the saying "as mad as a Hatter " -banned in the EU -German neurologist/toxicologist -Thomas Gebel --causes erethism mercurialis and if that doesn't worry you it makes males infertile.
They are a bit of a risk. They do look cool though. Have had zero noise issues with 866's doing rectifier duty in a PP 6CB5A amp. Now I have not looked for noise very thoroughly either; nothing has pointed to the need... 🙂
cheers,
Douglas
cheers,
Douglas
"I do find the DCG4/1000, this has 2.5V/4.8A filaments. So can I assume DCG/1000-01 is 2.5V but only 1A? "
Do your DCG/1000-01 look more or less the same as the pictures one can find for the DCG4/1000? There seems to be no obvious reason for the assumption you are wanting to make about the heater current.
I've heard it said that the heaters should be turned on before the HT is applied, so that the mercury has a chance to vaporise first. On the other hand, they were frequently used as the recifier tubes in tube-testers, and they would not have been pre-heated in those. They would also have had pretty rough mechanical treatment in a tube-tester, not to mention being shaken around and tilted at all sorts of angles, which again is something you see mentioned as not recommended for mercury rectifiers. So I guess they must be pretty rugged things!
Do your DCG/1000-01 look more or less the same as the pictures one can find for the DCG4/1000? There seems to be no obvious reason for the assumption you are wanting to make about the heater current.
I've heard it said that the heaters should be turned on before the HT is applied, so that the mercury has a chance to vaporise first. On the other hand, they were frequently used as the recifier tubes in tube-testers, and they would not have been pre-heated in those. They would also have had pretty rough mechanical treatment in a tube-tester, not to mention being shaken around and tilted at all sorts of angles, which again is something you see mentioned as not recommended for mercury rectifiers. So I guess they must be pretty rugged things!
Let's put some basic science into the content of mercury being released during a potential break.
Back in 2016, being worried on this topic, I deliberately launched a thread asking about the pressure inside a low pressure mercury rectifier we are using. Here's the link to this thread: What is the pressure inside a mercury rectifier? Thanks to member Hearinspace for explaining from a book quote about power MV rectifiers.
If we assume the worst, the vacuum inside a MV rectifier being 1/100, we can use the ideal gas equation, PV = nRT
-1/100mm of mercury translates into 1.33 Pascals.
- For a volume, let's take a coke can, which roughly should have the volume of an average MV rectifier, such as the 866. That translates to 350mL, or 0.000350 cubic meters.
-R is 8.314 (constant)
- For a temperature, we can assume 250C, which translates to 523K.
n translates to the number of moles of elemental mercury we must find, and PV = nRT becomes n = PV/RT,
n = 0.0004655 / 4348.22
n = 1.071 E-7
Now the molar weight of mercury is 200.59g. In the end the total amount of mercury is m = n x 200.59 and
m = 2.147E-5 grams or 21.5ug of mercury the maximum amount being immediately released into the atmosphere
If the vacuum had to be 1/1000mm of mercury, then the amount would be 2.5ug.
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According to google, there's approximately 4mg of mercury within an average CFL. Now this translates to 186 times the amount from the immediate vapors within an MV rectifier.
In my conclusion the real danger doesn't really come from spontaneous break-ups, but from storage of unknowingly mercury containing broken tubes for a long period of time, and sitting in this same room.
Back in 2016, being worried on this topic, I deliberately launched a thread asking about the pressure inside a low pressure mercury rectifier we are using. Here's the link to this thread: What is the pressure inside a mercury rectifier? Thanks to member Hearinspace for explaining from a book quote about power MV rectifiers.
If we assume the worst, the vacuum inside a MV rectifier being 1/100, we can use the ideal gas equation, PV = nRT
-1/100mm of mercury translates into 1.33 Pascals.
- For a volume, let's take a coke can, which roughly should have the volume of an average MV rectifier, such as the 866. That translates to 350mL, or 0.000350 cubic meters.
-R is 8.314 (constant)
- For a temperature, we can assume 250C, which translates to 523K.
n translates to the number of moles of elemental mercury we must find, and PV = nRT becomes n = PV/RT,
n = 0.0004655 / 4348.22
n = 1.071 E-7
Now the molar weight of mercury is 200.59g. In the end the total amount of mercury is m = n x 200.59 and
m = 2.147E-5 grams or 21.5ug of mercury the maximum amount being immediately released into the atmosphere
If the vacuum had to be 1/1000mm of mercury, then the amount would be 2.5ug.
*************************************
According to google, there's approximately 4mg of mercury within an average CFL. Now this translates to 186 times the amount from the immediate vapors within an MV rectifier.
In my conclusion the real danger doesn't really come from spontaneous break-ups, but from storage of unknowingly mercury containing broken tubes for a long period of time, and sitting in this same room.
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Yes they look exactly the same, like lamps, with the screw socket.
I guess I can just apply 2.5V and check the current. No need to apply HT for that. Should I expect normal glow as from any filament, compare to a 5U4 and the like?
Thanks for scientific info on the amounts of poison to expect 50AE.
oops. when young, a friend and I found a box of CFLs and played star wars in many duels. Our light sabers (the CFLs) would blow up as we battled. We'd be covered in dust from the broken CFL tubes. We did this several times over the years. Young and dumb... it actually explaines a few things...
I've been using DCG4 / 1000 RTC bought from a Polish eBay seller for 3 years. They're stored now due to my previous system being disassembled. I had to sell the most of it to begin my nightmarish audio transformer business.
Fine tubes, fine sound. Not really an excess of mercury within, so nothing to really worry about, I even accidentally broke a DCG4 / 1000, it was a Tesla though.
But one I stumbled on a 866 family Tesla rectifiers which had a few "pea grains" equivalent volume of mercury inside.
Yes, you can apply 2.5V and measure the current.
P.S. The white CFL dust should be phosphorus coating. It's a micronutrient in small amounts. If you did play outside, really negligible amounts of mercury should have been absorbed by you guys.. If you did in inside a closed space, it overall depends of volume, ventilation as well, and how quickly you cleaned the mess.
Mercury is much more worrisome in organic compounds, such as methyl mercury.
Fine tubes, fine sound. Not really an excess of mercury within, so nothing to really worry about, I even accidentally broke a DCG4 / 1000, it was a Tesla though.
But one I stumbled on a 866 family Tesla rectifiers which had a few "pea grains" equivalent volume of mercury inside.
Yes, you can apply 2.5V and measure the current.
P.S. The white CFL dust should be phosphorus coating. It's a micronutrient in small amounts. If you did play outside, really negligible amounts of mercury should have been absorbed by you guys.. If you did in inside a closed space, it overall depends of volume, ventilation as well, and how quickly you cleaned the mess.
Mercury is much more worrisome in organic compounds, such as methyl mercury.
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SemperFi,
If you are using any Pentodes or Beam Power tubes in your amplifier . . .
Then consider using Gas Regulator tubes for the Screen voltage.
There are 75V, 90V, 105V, 150V gas regulators. They have different ionization colors.
And they can be wired in series (what screen voltage do you need?).
I actually used an OD3 regulator in an all-triode stereo amplifier.
What did the OD3 do?
It was there for looks (and it also indicated when the B+ discharged to less than 150V when the power was turned off).
If you are using any Pentodes or Beam Power tubes in your amplifier . . .
Then consider using Gas Regulator tubes for the Screen voltage.
There are 75V, 90V, 105V, 150V gas regulators. They have different ionization colors.
And they can be wired in series (what screen voltage do you need?).
I actually used an OD3 regulator in an all-triode stereo amplifier.
What did the OD3 do?
It was there for looks (and it also indicated when the B+ discharged to less than 150V when the power was turned off).
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