Valve PSUs
 

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?

Probably could be rolled up and placed inside the original aluminium can,
too!

Valve PSUs
 

"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.

Valve PSUs
 

On Tue, 27 Jan 2015 14:49:49 +0000 (UTC), Custos Custodum
wrote:

"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.
Whats wrong with a 450volt rated cap?

Valve PSUs
 

In rec.radio.amateur.homebrew Rambo wrote:
On Tue, 27 Jan 2015 14:49:49 +0000 (UTC), Custos Custodum
wrote:

"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.
Whats wrong with a 450volt rated cap?

Nothing; he is starting out with the false premise that high voltage
capacitors are difficult to obtain, which they are not.



--
Jim Pennino

Valve PSUs
 

"Rambo" wrote in message
...
On Tue, 27 Jan 2015 14:49:49 +0000 (UTC), Custos Custodum
wrote:

"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.
Whats wrong with a 450volt rated cap?

Are they readily available?

Valve PSUs
 

On 1/27/2015 12:41 PM, gareth wrote:
"Rambo" wrote in message
...
On Tue, 27 Jan 2015 14:49:49 +0000 (UTC), Custos Custodum
wrote:

"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.
Whats wrong with a 450volt rated cap?

Are they readily available?

Yes. Did you even look for them?

--

Rick

Valve PSUs
 

On Tue, 27 Jan 2015 17:41:21 -0000, "gareth"
wrote:


Don't forget to include a suitable voltage divider chain.
Whats wrong with a 450volt rated cap?

Are they readily available?

How about:

http://uk.rs-online.com/web/p/alumin...itors/7441896/



http://uk.rs-online.com/web/generalD...ile=conditions
" All prices exclude VAT, which RS will add at the rate applicable at
the date of order despatch. RS reserves the right to change prices
without prior notice at any time."

Valve PSUs
 

On Tue, 27 Jan 2015, gareth wrote:

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?

Probably could be rolled up and placed inside the original aluminium can,
too!

You didn't specify what voltage you need.

For "average" high voltage, there are all those line side capacitors in
switching supplies. I thought they were about 450volts, but it's been a
while since I checked. So one can extract from a scrap computer supply,
or likely buy those as replacement parts. If they aren't high enough
voltage, then they are a better start for combining than 35v ones.

I was actually surprised 20 years ago when I discovered ripple in my
Tektronix scope. I found which of the many supplies was the problem by
using the scope itself, touching each of the high voltage lines until I
found one where the ripple increased. The needed capacitor wsa much larger
than "average" value in the days of electrolytics, I figured it would be
hard to find. Yet I checked the bins at the local surplus store, and
easily found a replacement, high enough voltage, and some large value like
100uF (which is large for tube power supplies).

If you're talking about high voltage for power amplifiers, I thought a lot
of those oil-filled capacitors from the old days were still viable. They
were sealed and hence don't dry out. The relatively small capacitance
ones but which have ceramic insulators for the leads to come through. They
were useful fifty years ago, they are apparently still good now. All you
have to do is dig deep enough to find them under more recent items.

If this is for a receiver, run it at a lower voltage. I gather the
Collins 75S line of receivers used "relatively low" voltage on the plates,
not real low but low relative to what other companies put on the plates.
I remember an article in CQ by Fred Brown where he updated his HRO for
subminiature tubes, and he followed this line about lower plate voltage,
though I can't remember the benefits he mentioned.

Michael

Valve PSUs
 

Michael Black wrote:

On Tue, 27 Jan 2015, gareth wrote:

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?

Probably could be rolled up and placed inside the original aluminium can,
too!

You didn't specify what voltage you need.

For "average" high voltage, there are all those line side capacitors in
switching supplies. I thought they were about 450volts, but it's been a
while since I checked. So one can extract from a scrap computer supply,
or likely buy those as replacement parts. If they aren't high enough
voltage, then they are a better start for combining than 35v ones.

I was actually surprised 20 years ago when I discovered ripple in my
Tektronix scope. I found which of the many supplies was the problem by
using the scope itself, touching each of the high voltage lines until I
found one where the ripple increased. The needed capacitor wsa much larger
than "average" value in the days of electrolytics, I figured it would be
hard to find. Yet I checked the bins at the local surplus store, and
easily found a replacement, high enough voltage, and some large value like
100uF (which is large for tube power supplies).

If you're talking about high voltage for power amplifiers, I thought a lot
of those oil-filled capacitors from the old days were still viable. They
were sealed and hence don't dry out. The relatively small capacitance
ones but which have ceramic insulators for the leads to come through. They
were useful fifty years ago, they are apparently still good now. All you
have to do is dig deep enough to find them under more recent items.

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.)





If this is for a receiver, run it at a lower voltage. I gather the
Collins 75S line of receivers used "relatively low" voltage on the plates,
not real low but low relative to what other companies put on the plates.
I remember an article in CQ by Fred Brown where he updated his HRO for
subminiature tubes, and he followed this line about lower plate voltage,
though I can't remember the benefits he mentioned.

Michael


--
Roger Hayter

Valve PSUs
 

"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.

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

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

==================

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.

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

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

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.

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

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

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

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

==================

Valve PSUs
 

On 1/28/2015 7:59 AM, Jerry Stuckle wrote:
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?

I'm not going to debate this with you. Your comments show a lack of
understanding of the topic. As I already explained, there is no
evidence to show there is a threshold for most carcinogens. It is just
a matter of the level of risk incurred. More exposure, more risk. Less
exposure, less risk.

As to the artificial sugar issue, first you need to understand there is
no such substance as "artificial sugar" that has been shown to cause
cancer.


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.

Scare tactics??? Facts!!! I have no idea how you leap from PCBs to
medicine.


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.

Ok, I guess there is no discussing the issue with you. Pollution by
PCBs is the poster child of how we are destroying our environment.


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.

Can you cite any reference that "small" amounts of NaOH are harmful? I
know for a fact you are talking through your hat on this issue.

"The Food and Drug Administration (FDA) allows sodium hydroxide as a
food additive in levels not to exceed 1%."

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=248&tid=45

I think a food additive at 1% concentration shows it is clearly not a
poison in a conventional sense of the word. It is a corrosive at high
enough concentrations and that is the only mechanism that can cause harm
from NaOH. Well, that and being hit on the head with a 50 pound sack of
it.

I'm not going to argue this with you. On many topics you just like to
argue and don't care about the facts.

--

Rick

Valve PSUs
 

On 1/28/2015 10:55 AM, rickman wrote:
On 1/28/2015 7:59 AM, Jerry Stuckle wrote:
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?

I'm not going to debate this with you. Your comments show a lack of
understanding of the topic. As I already explained, there is no
evidence to show there is a threshold for most carcinogens. It is just
a matter of the level of risk incurred. More exposure, more risk. Less
exposure, less risk.


That's good, because you are "debating" from a position of ignorance on
the subject.

As to the artificial sugar issue, first you need to understand there is
no such substance as "artificial sugar" that has been shown to cause
cancer.


Wrong again.


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.

Scare tactics??? Facts!!! I have no idea how you leap from PCBs to
medicine.


Just what I said. Your comments about PCBs in the rivers is pure scare
tactics. Show me proof from a *reliable source*. That doesn't include
some unknown person's blog on the internet.


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.

Ok, I guess there is no discussing the issue with you. Pollution by
PCBs is the poster child of how we are destroying our environment.


More bull****. PCBs were outlawed in the United States over 35 years
ago. Yet you still keep up with this crap.


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.

Can you cite any reference that "small" amounts of NaOH are harmful? I
know for a fact you are talking through your hat on this issue.


Yea, right.

"The Food and Drug Administration (FDA) allows sodium hydroxide as a
food additive in levels not to exceed 1%."

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=248&tid=45

I think a food additive at 1% concentration shows it is clearly not a
poison in a conventional sense of the word. It is a corrosive at high
enough concentrations and that is the only mechanism that can cause harm
from NaOH. Well, that and being hit on the head with a 50 pound sack of
it.


Which does not mean it is not poisonous.

I'm not going to argue this with you. On many topics you just like to
argue and don't care about the facts.


I care about the facts. Let's see you present some, instead of your
usual bull****.

Where are your "reliable sources" that PCBs are a major problem?

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

Valve PSUs
 

On Tue, 27 Jan 2015 13:01:55 +0000, gareth wrote:

a series /
parallel arrangement of those dinky 100uF 35V SMD ones?

Ripple current?



--
He who throws dirt loses ground.

Valve PSUs
 

On 27/01/2015 17:41, gareth wrote:
"Rambo" wrote in message
...
On Tue, 27 Jan 2015 14:49:49 +0000 (UTC), Custos Custodum
wrote:

"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.
Whats wrong with a 450volt rated cap?

Are they readily available?


All credit to you for posing the question Gareth, but real enthusiasts
know the answer as they take apart failed or obsolete equipment just out
of interest to see what is inside - and if anything is worth recovering.
Switch-mode PSUs - either as PSUs or as part of TVs, VDUs, printers
etc. etc. are a ready source of such capacitors. There's usually about
400v-worth of a couple of hundred microfarads of electrolytics in there.

Computer power supplies become dated so quickly - change of specs /
change of connector styles - that these caps are likely to have a fair
bit of life left in them - although they may over-smooth in a design
meant for the old combined 8+32uF - red spot for the 8 - that used to be
the bedrock of valve receiver PSUs. :)

PA

Valve PSUs
 

On 1/28/2015 11:57 AM, Jerry Stuckle wrote:
On 1/28/2015 10:55 AM, rickman wrote:
On 1/28/2015 7:59 AM, Jerry Stuckle wrote:
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?

I'm not going to debate this with you. Your comments show a lack of
understanding of the topic. As I already explained, there is no
evidence to show there is a threshold for most carcinogens. It is just
a matter of the level of risk incurred. More exposure, more risk. Less
exposure, less risk.


That's good, because you are "debating" from a position of ignorance on
the subject.

As to the artificial sugar issue, first you need to understand there is
no such substance as "artificial sugar" that has been shown to cause
cancer.


Wrong again.


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.

Scare tactics??? Facts!!! I have no idea how you leap from PCBs to
medicine.


Just what I said. Your comments about PCBs in the rivers is pure scare
tactics. Show me proof from a *reliable source*. That doesn't include
some unknown person's blog on the internet.


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.

Ok, I guess there is no discussing the issue with you. Pollution by
PCBs is the poster child of how we are destroying our environment.


More bull****. PCBs were outlawed in the United States over 35 years
ago. Yet you still keep up with this crap.


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.

Can you cite any reference that "small" amounts of NaOH are harmful? I
know for a fact you are talking through your hat on this issue.


Yea, right.

"The Food and Drug Administration (FDA) allows sodium hydroxide as a
food additive in levels not to exceed 1%."

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=248&tid=45

I think a food additive at 1% concentration shows it is clearly not a
poison in a conventional sense of the word. It is a corrosive at high
enough concentrations and that is the only mechanism that can cause harm
from NaOH. Well, that and being hit on the head with a 50 pound sack of
it.


Which does not mean it is not poisonous.

I'm not going to argue this with you. On many topics you just like to
argue and don't care about the facts.


I care about the facts. Let's see you present some, instead of your
usual bull****.

Where are your "reliable sources" that PCBs are a major problem?

Jerry, you don't want to discuss this as a scientific issue, so I'm not
going to bother. Just do a little research and you will find everything
I have posted is true. Here, I'll give you a start...

http://bit.ly/15PNwBN

Have a nice day.

--

Rick

Valve PSUs
 

Have a nice day.


Rick

hate that phrase ......

Valve PSUs
 

On 1/28/2015 1:19 PM, rickman wrote:
On 1/28/2015 11:57 AM, Jerry Stuckle wrote:
On 1/28/2015 10:55 AM, rickman wrote:
On 1/28/2015 7:59 AM, Jerry Stuckle wrote:
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?

I'm not going to debate this with you. Your comments show a lack of
understanding of the topic. As I already explained, there is no
evidence to show there is a threshold for most carcinogens. It is just
a matter of the level of risk incurred. More exposure, more risk. Less
exposure, less risk.


That's good, because you are "debating" from a position of ignorance on
the subject.

As to the artificial sugar issue, first you need to understand there is
no such substance as "artificial sugar" that has been shown to cause
cancer.


Wrong again.


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.

Scare tactics??? Facts!!! I have no idea how you leap from PCBs to
medicine.


Just what I said. Your comments about PCBs in the rivers is pure scare
tactics. Show me proof from a *reliable source*. That doesn't include
some unknown person's blog on the internet.


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.

Ok, I guess there is no discussing the issue with you. Pollution by
PCBs is the poster child of how we are destroying our environment.


More bull****. PCBs were outlawed in the United States over 35 years
ago. Yet you still keep up with this crap.


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.

Can you cite any reference that "small" amounts of NaOH are harmful? I
know for a fact you are talking through your hat on this issue.


Yea, right.

"The Food and Drug Administration (FDA) allows sodium hydroxide as a
food additive in levels not to exceed 1%."

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=248&tid=45

I think a food additive at 1% concentration shows it is clearly not a
poison in a conventional sense of the word. It is a corrosive at high
enough concentrations and that is the only mechanism that can cause harm
from NaOH. Well, that and being hit on the head with a 50 pound sack of
it.


Which does not mean it is not poisonous.

I'm not going to argue this with you. On many topics you just like to
argue and don't care about the facts.


I care about the facts. Let's see you present some, instead of your
usual bull****.

Where are your "reliable sources" that PCBs are a major problem?

Jerry, you don't want to discuss this as a scientific issue, so I'm not
going to bother. Just do a little research and you will find everything
I have posted is true. Here, I'll give you a start...

http://bit.ly/15PNwBN

Have a nice day.


I do want to discuss this as a scientific issue. Let me know when you
have some science to back you up.

For instance - from the epa.gov site in your link:

"What are polychlorinated biphenyls's health effects?
Some people who drink water containing polychlorinated biphenyls well in
excess of the maximum contaminant level (MCL) for many years could
experience changes in their skin, problems with their thymus gland,
immune deficiencies, or reproductive or nervous system difficulties, and
may have an increased risk of getting cancer."

Hardly the scare mongering you propound.

--
==================
Remove the "x" from my email address
Jerry Stuckle

==================

Valve PSUs
 

"Peter Able" stuck@home wrote in message
o.uk...
On 27/01/2015 17:41, gareth wrote:
..

Computer power supplies become dated so quickly - change of specs / change
of connector styles - that these caps are likely to have a fair bit of
life left in them - although they may over-smooth in a design meant for
the old combined 8+32uF - red spot for the 8 - that used to be the bedrock
of valve receiver PSUs. :)


When not using the origional value of capacitor in the power supply it is
important not to go too large. If the supply has a tube rectifier, the tube
will have a maximum capacitor rating. Too large of a value is bad for the
tube. If way too large and simiconductors are used for rectifiers, they can
become a problem also. Mainlly blown fuses when the supply is turned on
unless a soft start is included. That is usually a resistor in the primary
line that is shorted out after a second or so.

Valve PSUs
 

Every switch PSU uses high voltage capacitors

Valve PSUs
 

On 28/01/2015 19:54, Ralph Mowery wrote:
"Peter Able" stuck@home wrote in message
o.uk...
On 27/01/2015 17:41, gareth wrote:
.

Computer power supplies become dated so quickly - change of specs / change
of connector styles - that these caps are likely to have a fair bit of
life left in them - although they may over-smooth in a design meant for
the old combined 8+32uF - red spot for the 8 - that used to be the bedrock
of valve receiver PSUs. :)


When not using the origional value of capacitor in the power supply it is
important not to go too large. If the supply has a tube rectifier, the tube
will have a maximum capacitor rating. Too large of a value is bad for the
tube. If way too large and simiconductors are used for rectifiers, they can
become a problem also. Mainlly blown fuses when the supply is turned on
unless a soft start is included. That is usually a resistor in the primary
line that is shorted out after a second or so.


Hence my warning about a design specifying 8uF, Ralph. What will narrow
the gap will be that several ex-SMPSU capacitors will be used in series
- so the effective will be less than the individual capacitance.

As for limiting inrush, the transformer secondary and rectifier
impedances will, hopefully, take care of that - but as you write, these
things should be considered.

I wonder how much carnage was caused by those rectifier replacements for
valves which were a set of semiconductor rectifiers potted in an
International Octal body plug? Plug-in replacements - like hell !!

As for fusing - I guess that one can still get slow-blow fuses?

PA