Hazards of repair

[bob urz]

http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

 

[root]

bob urz <sound@inetnebr.com> wrote:

http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

At one point the article cited says electricity doesn't give any
warning. It has always been my experience that I can very lightly touch
and move my finger over a hot chassis and feel a sort of vibration. I
never got a shock doing that.

 

[Samuel M. Goldwasser]

root <NoEMail@home.org> writes:

bob urz <sound@inetnebr.com> wrote:
http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

At one point the article cited says electricity doesn't give any
warning. It has always been my experience that I can very lightly touch
and move my finger over a hot chassis and feel a sort of vibration. I
never got a shock doing that.

Yes, in fact, not even just a hot chassis, but any equipment that has
RFI filters and doesn't have its case grounded.

P.S. The hot chassis thing assumes you don't have your other hand on a
ground! It would very likely be more than a vibration in that case.

P.S.2 This is also the reason you can use a common neon tester to check
for live wires without having to connect the other probe to Neutral or
Ground.

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[Jim Yanik]

sam@repairfaq.org (Samuel M. Goldwasser) wrote in
news:umy0yklq5.fsf@repairfaq.org:

root <NoEMail@home.org> writes:

bob urz <sound@inetnebr.com> wrote:
http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

At one point the article cited says electricity doesn't give any
warning. It has always been my experience that I can very lightly
touch and move my finger over a hot chassis and feel a sort of
vibration. I never got a shock doing that.

Yes, in fact, not even just a hot chassis, but any equipment that has
RFI filters and doesn't have its case grounded.

P.S. The hot chassis thing assumes you don't have your other hand on a
ground! It would very likely be more than a vibration in that case.


P.S.2 This is also the reason you can use a common neon tester to
check for live wires without having to connect the other probe to
Neutral or Ground.

body capacitance couples a small amount of voltage through you to ground.
That's how the neon bulb lights.

--
Jim Yanik
jyanik
at
localnet
dot com

 

[Phil Hobbs]

On 1/1/2010 1:45 AM, bob urz wrote:

http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

Fun. Not 100% accurate, though--the getter inside tubes is not mercury,
it's usually sodium metal. Mercury has a high vapour pressure, and was
used in mercury vapour rectifiers and thyratrons, but not in ordinary
tubes. Also there's nothing too nasty about lithium other than that it
burns easily.

Happy New Year

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

 

[Phil Hobbs]

On 1/1/2010 1:45 AM, bob urz wrote:

http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

Fun. Not 100% accurate, though--the getter inside tubes is not mercury,
it's usually barium or sodium metal. Mercury has a high vapour
pressure, and was used in mercury vapour rectifiers and thyratrons, but
not in ordinary tubes. Also there's nothing too nasty about lithium
other than that it burns easily.

Happy New Year

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

 

[Phil Hobbs]

On 1/1/2010 6:56 AM, root wrote:

bob urz<sound@inetnebr.com> wrote:
http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

At one point the article cited says electricity doesn't give any
warning. It has always been my experience that I can very lightly touch
and move my finger over a hot chassis and feel a sort of vibration. I
never got a shock doing that.

The UK has 240V mains, though. I wouldn't want to use the fingertip
test for that.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

 

[Jeff Liebermann]

On Fri, 01 Jan 2010 00:45:50 -0600, bob urz <sound@inetnebr.com>
wrote:

http://www.bvws.org.uk/405alive/tech/safety.html
I especially like the radioactive turntable....
bob

Nice article on the hazardous of the repair biz but serious overkill.
It reads like the warning label on most drugs, which detail every
single last possible thing that might go wrong in litigious detail.
For example, I have several Geiger and scintillation counters. A few
years ago, I was actively looking for hot tubes and materials in
antique shops and junk piles. I hardly found anything.

However, like all warnings of the improbable, it only takes one near
disaster to justify the warning. In the early 1960's, I was a regular
customer of JJ Glass Surplus in Smog Angeles. (My fathers factory was
nearby). I thought the major hazard there was having a 10 meter high
pile of dead WWII radios fall on me, but soon found something else to
worry about. I purchased several IFF transponders for conversion to
ham frequencies. I forgot the exact model number but it looked
something like this:
<http://www.vk2bv.org/museum/bc966.htm>
I soon discovered that the explosive detonators were still attached to
one of the units. I made the mistake of telling my parents, who
called the police, which evacuated the neighborhood, and eventually
disarmed the radio.

Somewhat later, I worked in the 2-way radio install and repair
business in Smog Angeles. The average was one or two work related
fatality per year. It was usually from falling off a tower or getting
electrocuted by the high voltage found in all tube type transmitters.
In general, it made all of us safety conscious for perhaps a few days.

At another low point in my checkered career, I was doing warranty
service on consumer audio. Each warranty or test failure would arrive
from the distributor with a tag indicating why it had failed. One tag
had an ominous warning about a shorted power cord and hot chassis. I
applied all the necessary precautions, but all I could find was some
distortion in one of the channels. The next unit had a tag indicating
distorted audio. However, when I plugged it in, there were sparks and
smoke from the unit. Some idiot had switched the tags. I soon built
my first test box with circuit breakers.

These days, I fix computers, printers, and whatever drifts into the
shop. Not much in the way of hazards found in this stuff. Well,
sharp edges on some sheet metal have given me some nasty cuts, and few
volcanic capacitors, but nothing really dangerous. Most of the
warnings in the article really applies to antique hardware.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Fri, 01 Jan 2010 00:45:50 -0600, bob urz <sound@inetnebr.com>
wrote:

http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....
bob

More on the radioactive anti-static brush for turntables.
<http://www.blackcatsystems.com/science/radprod.html>
<http://www.angelfire.com/electronic/cwillis/rad/brush.html>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

On Jan 1, 9:22 am, Jeff Liebermann <je...@cruzio.com> wrote:
<snip>

However, like all warnings of the improbable, it only takes one
near
disaster to justify the warning.  In the early 1960's, I was a
regular
customer of JJ Glass Surplus in Smog Angeles.  (My fathers factory
was
nearby).  I thought the major hazard there was having a 10 meter
high
pile of dead WWII radios fall on me, but soon found something else
to
worry about.  I purchased several IFF transponders for conversion
to
ham frequencies.  I forgot the exact model number but it looked
something like this:
http://www.vk2bv.org/museum/bc966.htm
I soon discovered that the explosive detonators were still attached
to
one of the units.  I made the mistake of telling my parents, who
called the police, which evacuated the neighborhood, and eventually
disarmed the radio.

Somewhat later, I worked in the 2-way radio install and repair
business in Smog Angeles.  The average was one or two work related
fatality per year.  It was usually from falling off a tower or
getting
electrocuted by the high voltage found in all tube type
transmitters.
In general, it made all of us safety conscious for perhaps a few
days.

At another low point in my checkered career, I was doing warranty
service on consumer audio.  Each warranty or test failure would
arrive
from the distributor with a tag indicating why it had failed.  One
tag
had an ominous warning about a shorted power cord and hot chassis.
 I
applied all the necessary precautions, but all I could find was
some
distortion in one of the channels.  The next unit had a tag
indicating
distorted audio.  However, when I plugged it in, there were sparks
and
smoke from the unit.  Some idiot had switched the tags.  I soon
built
my first test box with circuit breakers.  

These days, I fix computers, printers, and whatever drifts into the
shop.  Not much in the way of hazards found in this stuff.  Well,
sharp edges on some sheet metal have given me some nasty cuts, and
few
volcanic capacitors, but nothing really dangerous.  Most of the
warnings in the article really applies to antique hardware.  

--
Jeff Liebermann     je...@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Did you see any of the HD wide shots of the rose parade this morning?
The smog issue is way better than when you were here in the '60s.

Happy New Year

G˛

 

[Jeff Liebermann]

On Fri, 1 Jan 2010 10:42:43 -0800 (PST), stratus46@yahoo.com wrote:

Did you see any of the HD wide shots of the rose parade this morning?

I sure did. I wanted to see the Cal Poly Rose Float entry. I missed
it on TV, but got it on the internet video feed:
<http://www.ktla.com/entertainment/roseparade/>
They won the Bob Hope Humor Award - Most Comical and Amusing.

More:
<http://www.asi.calpoly.edu/rose_float>
<http://www.cpprosefloat.org>
I worked on several floats in the late 1960's and rode inside one
year. Good weather, a few clouds, and as usual, moderately cold.

The smog issue is way better than when you were here in the '60s.

For sure. Cal Poly Pomona (CSU Pomona) is on the "inland empire" side
of Kellogg Hill. The ocean breeze from the west blows the smog from
Los Angeles over the top of the hill into the Pomona Valley. When the
wind changes direction at sundown, the smog piles up against the hill.
Do this action a few daze in a row and the smog was actually worse in
Pomona than in L.A. It was so bad one summer (in the dorms) that
visibility was only about 50ft. My eyes were tearing and breathing
was difficult. I visit occasionally and have noticed that the smog
situation has greatly improved. Much as I detest having my vehicle
smogged, it seems to be working.

Happy New Year
G˛

Likewise. Happy New Tax Year.... may all your deductions be accepted
by the IRS. My new years resolution is to not repeat any of the
screwups of last year, and to invent new ones for this year.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[whit3rd]

On Jan 1, 9:22 am, Jeff Liebermann <je...@cruzio.com> wrote:

On Fri, 01 Jan 2010 00:45:50 -0600, bob urz <so...@inetnebr.com
wrote:

http://www.bvws.org.uk/405alive/tech/safety.html
I especially like the radioactive turntable....

For example, I have several Geiger and scintillation counters.  A few
years ago, I was actively looking for hot tubes and materials in
antique shops and junk piles.  I hardly found anything.

It can be subtle. For lecture demo purposes, there's a collection
of radioactives in the U. of Washington physics department, including
mantles for Coleman lanterns, bright orange "Fiesta" dishes,
a navy chronometer (radium dial). Many vacuum tubes
have thoriated filaments or cathodes, and that's an alpha
emitter so you'll not find the radioactivity until the
tube is broken.

That Geiger counter was aimed at a LOT of radioactive material
even if it didn't click.

 

[Jeff Liebermann]

On Fri, 1 Jan 2010 13:45:43 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:

On Jan 1, 9:22 am, Jeff Liebermann <je...@cruzio.com> wrote:
On Fri, 01 Jan 2010 00:45:50 -0600, bob urz <so...@inetnebr.com
wrote:

http://www.bvws.org.uk/405alive/tech/safety.html
I especially like the radioactive turntable....

For example, I have several Geiger and scintillation counters.  A few
years ago, I was actively looking for hot tubes and materials in
antique shops and junk piles.  I hardly found anything.

It can be subtle. For lecture demo purposes, there's a collection
of radioactives in the U. of Washington physics department, including
mantles for Coleman lanterns, bright orange "Fiesta" dishes,
a navy chronometer (radium dial). Many vacuum tubes
have thoriated filaments or cathodes, and that's an alpha
emitter so you'll not find the radioactivity until the
tube is broken.

For hunting radioactive antiques, I used a home made scintillation
counter. I intentionally made it *NOT* look like the traditional gun
for obvious reasons. It's about 10 times as sensitive as my Geiger
counter and is perfect for sweeping large areas. In about 1986, I
found a bottle of Radithor, which is Radium Water. I later sold it to
a collector.

Since about 1995 Coleman lantern mantles use Yttrium Oxide and have no
radioactive material. I have some of the really old mantles that use
Thorium, an Alpha particle belcher. The old mantles are fairly hot in
the plastic bag which blocks most Alpha particles. However, when
removed from the bag, the mantles send my counter into hysterics at
about 8,000 counts per minute.

That Geiger counter was aimed at a LOT of radioactive material
even if it didn't click.

My idea of fun was in 1989, when Chernobyl did the meltdown thing, I
dragged a 1950's era Civil Defense Geiger counter to the local
supermarket and used it to check the produce. The manager was a
friend so I wasn't arrested, but I was adequately amused by all the
panicky customers and irate staff.

Here's another of my medical adventures with radioactivity and my
1950's era Geiger counter:
<http://groups.google.com/group/sci.electronics.design/msg/d193b6ad564773d0>

My favorite radioactive material is potassium (no sodium) salt. The
Potassium 40 is mildly radioactive and will do about 100 counts per
minute. Background is about 10 cpm. Sea salt will do about 50
counts. This is always fun to demonstrate in a health food store.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[JeffM]

Jeff Liebermann wrote:

Smog Angeles
[...]
the explosive detonators were still attached to one of the units
[...]
One tag had an ominous warning about a shorted power cord
and hot chassis[...]The next unit had[...]sparks and smoke
from the unit. Some idiot had switched the tags.

A fun post to read.

Happy New Year

 

[Jeff Liebermann]

On Fri, 1 Jan 2010 22:00:02 -0800 (PST), JeffM <jeffm_@email.com>
wrote:

Jeff Liebermann wrote:
[...]Smog Angeles
[...]
the explosive detonators were still attached to one of the units
[...]
One tag had an ominous warning about a shorted power cord
and hot chassis[...]The next unit had[...]sparks and smoke
from the unit. Some idiot had switched the tags.

A fun post to read.

Not if you're the person involved. The whole neighborhood was very
angry with me for having to evacuate for most of the day. Nothing
like standing around in bath robe or pajamas for most of the day
waiting for the bomb squad to declare it safe to go home.

Also, the shorted power cord scared me quite nicely. Not fun.

Happy New Year

Yeah right. New laws, new taxes, same old headaches.
<http://www.latimes.com/news/local/la-me-new-laws1-2010jan01,0,3437892,full.story>

Long ago, one of my roommates received "Family Safety and Health"
magazine.
<http://www.amazon.com/Family-Safety-and-Health/dp/B00006KDVL.
More correctly, it should have been called "Family Paranoia" magazine.
The idea was to improve off the job safety for employees. Want to
spend a nice day a the beach? Well, first you get warned about
sharks, rip tide, pollution, jelly fish, sunburn, sand fleas, etc.
After reading all that, if I actually made it to the beach, I probably
would hide in the car. It's the same way with all the safety issues
in the repair biz. They're good to know about in advance, but if you
followed the list religiously, you're unlikely to enjoy the work.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[N_Cook]

Jeff Liebermann <jeffl@cruzio.com> wrote in message
newsausj5lhs807g6mq3v91j6mjlsfgalg53a@4ax.com...

On Fri, 1 Jan 2010 13:45:43 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Jan 1, 9:22 am, Jeff Liebermann <je...@cruzio.com> wrote:
On Fri, 01 Jan 2010 00:45:50 -0600, bob urz <so...@inetnebr.com
wrote:

http://www.bvws.org.uk/405alive/tech/safety.html
I especially like the radioactive turntable....

For example, I have several Geiger and scintillation counters. A few
years ago, I was actively looking for hot tubes and materials in
antique shops and junk piles. I hardly found anything.

It can be subtle. For lecture demo purposes, there's a collection
of radioactives in the U. of Washington physics department, including
mantles for Coleman lanterns, bright orange "Fiesta" dishes,
a navy chronometer (radium dial). Many vacuum tubes
have thoriated filaments or cathodes, and that's an alpha
emitter so you'll not find the radioactivity until the
tube is broken.

For hunting radioactive antiques, I used a home made scintillation
counter. I intentionally made it *NOT* look like the traditional gun
for obvious reasons. It's about 10 times as sensitive as my Geiger
counter and is perfect for sweeping large areas. In about 1986, I
found a bottle of Radithor, which is Radium Water. I later sold it to
a collector.

Since about 1995 Coleman lantern mantles use Yttrium Oxide and have no
radioactive material. I have some of the really old mantles that use
Thorium, an Alpha particle belcher. The old mantles are fairly hot in
the plastic bag which blocks most Alpha particles. However, when
removed from the bag, the mantles send my counter into hysterics at
about 8,000 counts per minute.

That Geiger counter was aimed at a LOT of radioactive material
even if it didn't click.

My idea of fun was in 1989, when Chernobyl did the meltdown thing, I
dragged a 1950's era Civil Defense Geiger counter to the local
supermarket and used it to check the produce. The manager was a
friend so I wasn't arrested, but I was adequately amused by all the
panicky customers and irate staff.

Here's another of my medical adventures with radioactivity and my
1950's era Geiger counter:

http://groups.google.com/group/sci.electronics.design/msg/d193b6ad564773d0

My favorite radioactive material is potassium (no sodium) salt. The
Potassium 40 is mildly radioactive and will do about 100 counts per
minute. Background is about 10 cpm. Sea salt will do about 50
counts. This is always fun to demonstrate in a health food store.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Are you related to this guy?
The Radioactive Boy Scout: The True Story of a Boy Who Built a Nuclear
Reactor in His Shed
"
David Hahn, a boy scout, wanted to earn his science merit badge. He could
have done an experiment with bicarbonate of soda, like most other kids. But
he didn't. He built a nuclear reactor in his shed instead.David Hahn's
gospel was The Golden Book of Chemistry Experiments. While his friends were
learning to play baseball or dreaming of owning their first car, David was
in the middle of an increasingly hazardous trail of chemical experiments.
Moving on from routine explosions that forced his work from his bedroom to
the garden shed, David quickly determined to build a nuclear reactor. For
this he had to make a neutron gun, dupe officials at the Nuclear Regulatory
Commission to provide him with information and imitate a professor of
nuclear physics in order to obtain purified radioactive elements, all of
which he did.David, sporting a gas mask for protection, took to the potting
shed with his ever more unstable and dangerous load. His diligence and
ultimate success triggered the Federal Radiological Emergency Response Plan:
a team of men in moon suits who deconstructed the shed and loaded it and all
its contents into steel drums emblazoned with radioactive warning signs.
This is a true story. Through it, man's innocent obsession and fatal
engagement with nuclear reactivity is told with surreal wonder.
"
http://www.amazon.co.uk/gp/product/1841152293?ie=UTF8&tag=zoonomian-21&linkC
ode=as2&camp=1634&creative=6738&creativeASIN=1841152293



--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm

 

[ian field]

"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4B3E1EA1.7050706@electrooptical.net...

On 1/1/2010 1:45 AM, bob urz wrote:
http://www.bvws.org.uk/405alive/tech/safety.html

I especially like the radioactive turntable....

bob

Fun. Not 100% accurate, though--the getter inside tubes is not mercury,
it's usually sodium metal. Mercury has a high vapour pressure, and was
used in mercury vapour rectifiers and thyratrons, but not in ordinary
tubes. Also there's nothing too nasty about lithium other than that it
burns easily.

Lithium compounds were used as antipsychotic drugs, but apparently they're
pretty nasty stuff and have been replaced with other things.

 

[Mike Tomlinson]

In article <4B3E1EF3.3030202@electrooptical.net>, Phil Hobbs <pcdhSpamMe
Senseless@electrooptical.net> writes

Mercury has a high vapour
pressure, and was used in mercury vapour rectifiers

There's some fantastic photos of those on the web. I don't care how
safe they are; I'd be very reluctant to go near one, operating or not.

--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png

 

[Jeff Liebermann]

On Sat, 2 Jan 2010 12:19:37 -0000, "N_Cook" <diverse@tcp.co.uk> wrote:

Are you related to this guy?

No relationship or connection. There are some small similarities
between his original motivation and mine. I won't go there.

The Radioactive Boy Scout: The True Story of a Boy Who Built a Nuclear
Reactor in His Shed

I've read the book with much fascination. Great story and well worth
reading. The problem is the book contains a few errors and some
omissions possibly intended to prevent imitation. Near the end, he
had successfully built a crude breeder reactor. Fortunately it never
hit critical mass.
<http://en.wikipedia.org/wiki/David_Hahn>

A photo shows the effects of what I guess is excessive radioactive
Thorium byproducts (i.e. Thoron gas) exposure:
<http://www.freerepublic.com/focus/f-news/1887600/posts>
Also note the photo of his original reactor.

I haven't tried to build a fusion reactor, yet:
<http://www.fusor.net>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[JeffM]

JeffM wrote:
A fun post to read.

Jeff Liebermann wrote:
Not if you're the person involved.

Exactly.

http://google.com/search?q=%22*-definition-of-comedy-is-tragedy-plus-time

Happy New Year

Yeah right. New laws, new taxes, same old headaches.

Mostly bureaucrats looking like they're doing SOMETHING.

http://google.com/search?q=%22+difference.between.change.and.progress

Changes do keep the lawyers and other criminals occupied
figuring out how to end-run the new regulations,
showing us all how they're smarter than everybody else.