Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #11   Report Post  
Old January 28th 15, 02:47 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Nov 2012
Posts: 989
Default 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   Report Post  
Old January 28th 15, 03:37 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Oct 2012
Posts: 1,067
Default 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   Report Post  
Old January 28th 15, 04:06 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 702
Default 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   Report Post  
Old January 28th 15, 04:18 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Nov 2012
Posts: 989
Default 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   Report Post  
Old January 28th 15, 07:11 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Feb 2014
Posts: 80
Default 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   Report Post  
Old January 28th 15, 08:05 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Jan 2015
Posts: 1
Default 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   Report Post  
Old January 28th 15, 09:45 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 137
Default 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   Report Post  
Old January 28th 15, 11:29 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Jan 2015
Posts: 185
Default 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   Report Post  
Old January 28th 15, 11:51 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Nov 2007
Posts: 568
Default 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   Report Post  
Old January 28th 15, 12:59 PM posted to uk.radio.amateur,rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Oct 2012
Posts: 1,067
Default 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

==================
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
PSUs: current-limiting and crowbarring - incompatible? [email protected] Homebrew 9 October 24th 06 11:48 PM
Avo Valve tester FS milradio Homebrew 0 December 17th 03 07:58 PM
Avo Valve tester FS milradio Homebrew 0 December 17th 03 07:58 PM
Xtals for valve tx. SB Homebrew 8 December 6th 03 01:15 PM
Xtals for valve tx. SB Homebrew 0 November 28th 03 04:01 PM


All times are GMT +1. The time now is 09:21 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017