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#11
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Valve PSUs
On 1/27/2015 7:59 PM, Ralph Mowery wrote:
"Roger Hayter" wrote in message ... The oils in these old capacitors are often PCBs (polychlorinated bi-phenyls) which are quite toxic. And they can leak slightly even if not visibly. So I wouldn't have them in a house occupied by any non-old non-amateurs. (A bit late for me to take up H & S on my own behalf.) The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? -- Rick |
#12
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Valve PSUs
On 1/27/2015 9:47 PM, rickman wrote:
On 1/27/2015 7:59 PM, Ralph Mowery wrote: "Roger Hayter" wrote in message ... The oils in these old capacitors are often PCBs (polychlorinated bi-phenyls) which are quite toxic. And they can leak slightly even if not visibly. So I wouldn't have them in a house occupied by any non-old non-amateurs. (A bit late for me to take up H & S on my own behalf.) The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? He's right - it isn't really that toxic. It takes multiple exposures over a long time to do any harm; getting some on your hands won't hurt you. And even when it does harm you, it's not fatal. But it does cause nervous system disorders. There are a lot of things much more toxic you can easily find, even at the grocery store. Drain cleaner comes to mind... -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
#13
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Valve PSUs
"rickman" wrote in message ... The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? PCB is often talked about like a few drops will kill you. Many things around the house are much more toxic. Look at all the dangers listed on the drugs they advertise on the TV. While we don't want the PCP oil to get into the food chain, some tree huggers just jumped on that and tried to make it sound like it would kill you or cause brain damage or some such junk as that. While it will do that, it takes more than a few drops and not many people are going to just drink a glass of it. |
#14
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Valve PSUs
On 1/27/2015 10:37 PM, Jerry Stuckle wrote:
On 1/27/2015 9:47 PM, rickman wrote: On 1/27/2015 7:59 PM, Ralph Mowery wrote: "Roger Hayter" wrote in message ... The oils in these old capacitors are often PCBs (polychlorinated bi-phenyls) which are quite toxic. And they can leak slightly even if not visibly. So I wouldn't have them in a house occupied by any non-old non-amateurs. (A bit late for me to take up H & S on my own behalf.) The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? He's right - it isn't really that toxic. It takes multiple exposures over a long time to do any harm; getting some on your hands won't hurt you. And even when it does harm you, it's not fatal. But it does cause nervous system disorders. There are a lot of things much more toxic you can easily find, even at the grocery store. Drain cleaner comes to mind... I asked what the source of this "fact" is. PCBs cause cancer. I have never heard exposure to a carcinogen is safe as long as it is only for a "short time" or "just once". Scientists have tried to establish exposure thresholds, but this is speculation. The issue is how much risk are you willing to accept rather than there being a threshold of harm. Just in the last few years I learned that we have so extensively polluted our environment that it is not recommended to eat the fish from nearly any river in the several US states where I live. This pollution is largely in the form of PCBs. It is not from point sources that can be cleaned up. It is widespread from small sources. Essentially, we integrated this stuff into our lives to the extent that we are regularly bathed in it. It seems people believe our persistent destruction of the environment is something that happens somewhere else or the harm is overblown or that it is something that we will have to deal with in the future. But this is not true. The future is here and we are all living in the results of our own ignorance. BTW, unlike carcinogens, I can eat drain cleaner every day in adequately small amounts. NaOH, Sodium Hydroxide. I have sodium in my diet as an essential nutrient and hydroxide exists in all water solutions. NaOH is not actually a poison, it is a corrosive. If you come into contact with it in high concentrations it is harmful. In low concentrations it is harmless in the true sense. I know this for a fact. Without harm, I have handled NaOH in concentrations high enough that I can feel the soapiness. So your analogy is poor. -- Rick |
#15
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Valve PSUs
On 27/01/2015 17:41, gareth wrote:
"Rambo" wrote in message Whats wrong with a 450volt rated cap? Are they readily available? Yes they are commonly used in 3 phase applications for ripple control or power factor correction. They can range from diddy PCB types right up to tin buckets weighing several kilograms. You can get them from RS, Farnell etc Andy |
#16
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Valve PSUs
You should be able to find suitable capacitors in car stereo set ups, there
are lots of options on eBay too "Custos Custodum" wrote in message ... "gareth" wrote in : The problems associated with replacing (or even obtaining) the HT reservoir capacitors in valve projects might be replace with a series / parallel arrangement of those dinky 100uF 35V SMD ones? There's still a significant market for valve-based guitar amplifiers, so somebody must be making the HT capacitors for them. Probably could be rolled up and placed inside the original aluminium can, too! Don't forget to include a suitable voltage divider chain. |
#17
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Valve PSUs
"Ralph Mowery" wrote in message
... "rickman" wrote in message ... The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? PCB is often talked about like a few drops will kill you. Many things around the house are much more toxic. Look at all the dangers listed on the drugs they advertise on the TV. While we don't want the PCP oil to get into the food chain, some tree huggers just jumped on that and tried to make it sound like it would kill you or cause brain damage or some such junk as that. While it will do that, it takes more than a few drops and not many people are going to just drink a glass of it. I'll stick to beer, thanks. -- ;-) .. 73 de Frank Turner-Smith G3VKI - mine's a pint. .. http://turner-smith.co.uk |
#18
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Valve PSUs
Ralph Mowery wrote:
"rickman" wrote in message ... The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? PCB is often talked about like a few drops will kill you. Many things around the house are much more toxic. Look at all the dangers listed on the drugs they advertise on the TV. While we don't want the PCP oil to get into the food chain, some tree huggers just jumped on that and tried to make it sound like it would kill you or cause brain damage or some such junk as that. While it will do that, it takes more than a few drops and not many people are going to just drink a glass of it. Yes. It is not very poisonous, but it adds long term to the burden of toxins the body has to deal with. If you have children or grandchildren in the house you might want to avoid even a 1% increase in the chance of them getting cancer or neurological damage in 50 years time just so you can use a 70 year old capacitor. Or you might decide it is a negligible risk. At a population level, it is probably sensible to try to keep PCBs out of the environment. A hundred little things may add up to a significant improvement in health in the next century. Why not do them if the cost is not too great now? -- Roger Hayter |
#19
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Valve PSUs
In message , Roger Hayter
writes Ralph Mowery wrote: "rickman" wrote in message ... The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? PCB is often talked about like a few drops will kill you. Many things around the house are much more toxic. Look at all the dangers listed on the drugs they advertise on the TV. While we don't want the PCP oil to get into the food chain, some tree huggers just jumped on that and tried to make it sound like it would kill you or cause brain damage or some such junk as that. While it will do that, it takes more than a few drops and not many people are going to just drink a glass of it. Yes. It is not very poisonous, but it adds long term to the burden of toxins the body has to deal with. If you have children or grandchildren in the house you might want to avoid even a 1% increase in the chance of them getting cancer or neurological damage in 50 years time just so you can use a 70 year old capacitor. Or you might decide it is a negligible risk. At a population level, it is probably sensible to try to keep PCBs out of the environment. A hundred little things may add up to a significant improvement in health in the next century. Why not do them if the cost is not too great now? A case of "Every little doesn't help"? -- Ian |
#20
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Valve PSUs
On 1/27/2015 11:18 PM, rickman wrote:
On 1/27/2015 10:37 PM, Jerry Stuckle wrote: On 1/27/2015 9:47 PM, rickman wrote: On 1/27/2015 7:59 PM, Ralph Mowery wrote: "Roger Hayter" wrote in message ... The oils in these old capacitors are often PCBs (polychlorinated bi-phenyls) which are quite toxic. And they can leak slightly even if not visibly. So I wouldn't have them in a house occupied by any non-old non-amateurs. (A bit late for me to take up H & S on my own behalf.) The PCB is not really that toxic. The problem is that it almost does not break down and gets into the food chain. You can touch it and even get a small ammount in your mouth without any harm to you. I don't mean drink it, but say you get some on your hand and lick a drop or two off your finger. Wow! What is your basis for saying that? Are you trying to say if it doesn't kill you outright there is no danger? He's right - it isn't really that toxic. It takes multiple exposures over a long time to do any harm; getting some on your hands won't hurt you. And even when it does harm you, it's not fatal. But it does cause nervous system disorders. There are a lot of things much more toxic you can easily find, even at the grocery store. Drain cleaner comes to mind... I asked what the source of this "fact" is. PCBs cause cancer. I have never heard exposure to a carcinogen is safe as long as it is only for a "short time" or "just once". Scientists have tried to establish exposure thresholds, but this is speculation. The issue is how much risk are you willing to accept rather than there being a threshold of harm. Exactly. There are no thresholds because scientists cannot determine how much is required to cause a problem. Unlike drain cleaner, for instance. And there are a lot of things which cause cancer. Even artificial sugar has been blamed for causing cancer. So are you going to stop using anything containing artificial sugar? Just in the last few years I learned that we have so extensively polluted our environment that it is not recommended to eat the fish from nearly any river in the several US states where I live. This pollution is largely in the form of PCBs. It is not from point sources that can be cleaned up. It is widespread from small sources. Essentially, we integrated this stuff into our lives to the extent that we are regularly bathed in it. More scare tactics. Pollution from medications (especially hormones) being flushed down the drain is a much bigger problem. So I guess we should stop taking any medications. It seems people believe our persistent destruction of the environment is something that happens somewhere else or the harm is overblown or that it is something that we will have to deal with in the future. But this is not true. The future is here and we are all living in the results of our own ignorance. Which still has nothing to do with PCBs - except for scare tactics. BTW, unlike carcinogens, I can eat drain cleaner every day in adequately small amounts. NaOH, Sodium Hydroxide. I have sodium in my diet as an essential nutrient and hydroxide exists in all water solutions. NaOH is not actually a poison, it is a corrosive. If you come into contact with it in high concentrations it is harmful. In low concentrations it is harmless in the true sense. I know this for a fact. Without harm, I have handled NaOH in concentrations high enough that I can feel the soapiness. So your analogy is poor. No, you have sodium chloride (NaCl) in your diet, not NaOH. And even small amounts of NaOH have been shown to be harmful - it is considered a poison. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
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