In article , "K Wind"
writes:

"Paul Burridge" wrote in message
.. .

The question seems daft, but bear with me, gentlemen. Has anyone ever
had an electric shock that they feel lucky to have survived?

Would 1,500VDC with 6mA capability flowing through one arm and out the other
be considered lethal? At one time, I knew how much current was considered
lethal, but have forgotten.

Think of "30-30" as a mnemonic.

If the source has over 30 Volts and can supply over 30 milliamperes
through the cardiac region, you will go into cardiac fibrilation.

High voltage with little supply current will affect the nerves and the
resulting muscle spasms can cause other kinds of injuries, some
that may be fatal.

DON'T DO IT. PAY ATTENTION!

Len Anderson
still living in the same reality I was born into...

In article , "RP Henry" richard.p.henry@saic dot
com writes:

"Tom Sevart" wrote in message
...

"WB3FUP (Mike Hall)" wrote in message
...
10KV to fire magnetron in counter battery radar. Took six marines to stop
me from burying my screw driver in the chest of the asshole that thought
it
would be cute to push the radiate button.

I remember hearing the story of an Air Force tech working on a 30' radar
dish. For some dumb reason, someone energized it and promptly microwaved
him to death.

Some of these stories are hair rasing... and I'm too much of a weenie to
stick my tongue on a 9V battery...

A Raytheon corporate legend is that one of the engineers discovered the
microwave oven principle when a radar melted a chocolate bar in his shirt
pocket.

That's been an Urban Legend for decades...probably a PR plant from
someone at Raytheon's Santa Barbara, CA, division that deveeloped
the RadaRange (originally a trademark of Raytheon before they sold that
consumer line to Amana).

========

While all the war stories and chit-chat are entertaining, please consider
a real-life tragedy that happened to a TV broadcast van in Los Angeles
last year. The van had stopped and erected its field-to-transmitter link
dish to Mount Wilson where the TV transmitter was. Standard
procedure here to get a clear shot above buildings and obstructions,
all the field vans have such erectable dishes.

Nobody in the field crew seems to have noticed that the van was under
a "high-line" of higher-voltage lines common in local area power
distribution. The dish and its two-section small crane came in contact
with the high-line. Somehow the kind of contact sent a good-sized
electrical power flow down into the van. A woman reporter was severely
burned in addition to being knocked unconscious...burns severe enough
to require amputation of part of an arm and part of a leg. She survived
but spent many months in the hospital and physical therapy, had to use
a wheelchair to get around even though active and healthy and not yet
40 before the accident.

This incident was clearly a result of STUPID NON-ATTENTION by the
TV field crew. That high-line distribution is common all over this city
and adjoining cities. To erect the link dish right into power wiring of
any kind was just compounding the stupidity.

I mention this because amateur radio nearly always involves outside
antennas in urban areas close to utility power wiring on poles. The
possibility of fatal or terrible electric shock isn't confined to some
radio-electronic box interior...it exists out in the open, in plain sight.
Keep it in mind to avoid frying that mind.

Len Anderson
retired (and still living) electronic engineer person

In article , "RP Henry" richard.p.henry@saic dot
com writes:

"Tom Sevart" wrote in message
...

"WB3FUP (Mike Hall)" wrote in message
...
10KV to fire magnetron in counter battery radar. Took six marines to stop
me from burying my screw driver in the chest of the asshole that thought
it
would be cute to push the radiate button.

I remember hearing the story of an Air Force tech working on a 30' radar
dish. For some dumb reason, someone energized it and promptly microwaved
him to death.

Some of these stories are hair rasing... and I'm too much of a weenie to
stick my tongue on a 9V battery...

A Raytheon corporate legend is that one of the engineers discovered the
microwave oven principle when a radar melted a chocolate bar in his shirt
pocket.

That's been an Urban Legend for decades...probably a PR plant from
someone at Raytheon's Santa Barbara, CA, division that deveeloped
the RadaRange (originally a trademark of Raytheon before they sold that
consumer line to Amana).

========

While all the war stories and chit-chat are entertaining, please consider
a real-life tragedy that happened to a TV broadcast van in Los Angeles
last year. The van had stopped and erected its field-to-transmitter link
dish to Mount Wilson where the TV transmitter was. Standard
procedure here to get a clear shot above buildings and obstructions,
all the field vans have such erectable dishes.

Nobody in the field crew seems to have noticed that the van was under
a "high-line" of higher-voltage lines common in local area power
distribution. The dish and its two-section small crane came in contact
with the high-line. Somehow the kind of contact sent a good-sized
electrical power flow down into the van. A woman reporter was severely
burned in addition to being knocked unconscious...burns severe enough
to require amputation of part of an arm and part of a leg. She survived
but spent many months in the hospital and physical therapy, had to use
a wheelchair to get around even though active and healthy and not yet
40 before the accident.

This incident was clearly a result of STUPID NON-ATTENTION by the
TV field crew. That high-line distribution is common all over this city
and adjoining cities. To erect the link dish right into power wiring of
any kind was just compounding the stupidity.

I mention this because amateur radio nearly always involves outside
antennas in urban areas close to utility power wiring on poles. The
possibility of fatal or terrible electric shock isn't confined to some
radio-electronic box interior...it exists out in the open, in plain sight.
Keep it in mind to avoid frying that mind.

Len Anderson
retired (and still living) electronic engineer person

On Sat, 09 Aug 2003 12:11:19 -0700, Mark Fergerson
wrote:

Now that you've explained what you meant, I'll mention
that I must be on at least my fifth parallel Universe.

Don't bother counting. You have a *lot* more to go, it seems.
--

"I believe history will be kind to me, since I intend
to write it." - Winston Churchill

On Sat, 09 Aug 2003 12:11:19 -0700, Mark Fergerson
wrote:

Now that you've explained what you meant, I'll mention
that I must be on at least my fifth parallel Universe.

Don't bother counting. You have a *lot* more to go, it seems.
--

"I believe history will be kind to me, since I intend
to write it." - Winston Churchill

Ian White, G3SEK wrote:

. . .

An interesting thing happens when you switch off to isolate part of the
house wiring, and then cut the "dead" three-wire cable. (We call it
"flat twin and earth". It has PVC-insulated hot and neutral wires with a
bare ground wire in between, all in a flattish grey or white PVC sheath.
Is this what you call "Romex"?)

Yes, that's "Romex". The official designation is type NM (for
Non-Metallic). 12 gauge wire, for 20 amps maximum, is "12-2 with ground"
and 14 gauge, for 15 amps, is "14-2 with ground". Those are the most
common sizes for residential lighting and outlet circuits.

If you cut the hot and ground wires
together, nothing happens; but if you cut the neutral and ground wires
together, the RCD trips. That's a puzzle the first time it happens, but
it's because that cable isn't quite as "dead" as you think. the
isolating switches interrupt only the hot wire, so the neutral and earth
are still being shared with everything else that's switched on in the
house.

Does that happen in the USA, or do you have two-pole isolating switches
for individual sub-circuits?

I don't quite follow where you're cutting the wires or where the RCD is
located. Here, you can get a GFCI as either a circuit breaker you
install in the service box to protect a whole circuit, or incorporated
in a duplex outlet. Both are easily identifiable by the conspicuous test
button. The breaker differs from an ordinary breaker in that the neutral
wire is also routed through it.

Circuit breakers interrupt only the "hot" wire. It's been a long time
since I studied the code (NEC - National Electrical Code), but I'm sure
that switching the neutral is still a no-no. Neutral wires are all
brought back to the service box, where they're all connected to the
central power feed wire. The safety grounds are brought back to the
service box separately, where they're connected to the same point as the
neutrals. Neutral and safety ground are connected together only at the
service box, nowhere else.

This isn't totally idle curiosity. If there's an electrical problem
while we're staying with the in-laws in Atlanta, I'm the one who's
supposed to know about these things...

I'd at least get a home-handyman book on electrical wiring, and a real
code book if you'll be doing anything other than pretty simple wiring.
The rules are quite complex, dictating things like how close to a
junction box wires have to be supported, how they can be routed, what
size junction box is required for various combinations of
entering/exiting wires, etc. In Oregon, wiring can legally be done only
by the homeowner or a licensed electrician, but each state and many
localities have their own rules. I think all, or just about all, the
states now at least have agreed to use the NEC. (You're probably
technically forbidden to touch the wiring, depending on Georgia and
Atlanta regulations.) The presence of non-code wiring could result in
non-payment of insurance if a home were to have an electrical fire.

I wired the addition to our home, which involved adding seven circuits
including outside outlets and lights. I also replaced and upgraded the
service box. Those jobs were done with electrical work permits, and both
were inspected and passed. So I have done a bit of this before. But it
was a lot of years ago now, the code evolves, and my memory fades.

Roy Lewallen, W7EL

Ian White, G3SEK wrote:

. . .

An interesting thing happens when you switch off to isolate part of the
house wiring, and then cut the "dead" three-wire cable. (We call it
"flat twin and earth". It has PVC-insulated hot and neutral wires with a
bare ground wire in between, all in a flattish grey or white PVC sheath.
Is this what you call "Romex"?)

Yes, that's "Romex". The official designation is type NM (for
Non-Metallic). 12 gauge wire, for 20 amps maximum, is "12-2 with ground"
and 14 gauge, for 15 amps, is "14-2 with ground". Those are the most
common sizes for residential lighting and outlet circuits.

If you cut the hot and ground wires
together, nothing happens; but if you cut the neutral and ground wires
together, the RCD trips. That's a puzzle the first time it happens, but
it's because that cable isn't quite as "dead" as you think. the
isolating switches interrupt only the hot wire, so the neutral and earth
are still being shared with everything else that's switched on in the
house.

Does that happen in the USA, or do you have two-pole isolating switches
for individual sub-circuits?

I don't quite follow where you're cutting the wires or where the RCD is
located. Here, you can get a GFCI as either a circuit breaker you
install in the service box to protect a whole circuit, or incorporated
in a duplex outlet. Both are easily identifiable by the conspicuous test
button. The breaker differs from an ordinary breaker in that the neutral
wire is also routed through it.

Circuit breakers interrupt only the "hot" wire. It's been a long time
since I studied the code (NEC - National Electrical Code), but I'm sure
that switching the neutral is still a no-no. Neutral wires are all
brought back to the service box, where they're all connected to the
central power feed wire. The safety grounds are brought back to the
service box separately, where they're connected to the same point as the
neutrals. Neutral and safety ground are connected together only at the
service box, nowhere else.

This isn't totally idle curiosity. If there's an electrical problem
while we're staying with the in-laws in Atlanta, I'm the one who's
supposed to know about these things...

I'd at least get a home-handyman book on electrical wiring, and a real
code book if you'll be doing anything other than pretty simple wiring.
The rules are quite complex, dictating things like how close to a
junction box wires have to be supported, how they can be routed, what
size junction box is required for various combinations of
entering/exiting wires, etc. In Oregon, wiring can legally be done only
by the homeowner or a licensed electrician, but each state and many
localities have their own rules. I think all, or just about all, the
states now at least have agreed to use the NEC. (You're probably
technically forbidden to touch the wiring, depending on Georgia and
Atlanta regulations.) The presence of non-code wiring could result in
non-payment of insurance if a home were to have an electrical fire.

I wired the addition to our home, which involved adding seven circuits
including outside outlets and lights. I also replaced and upgraded the
service box. Those jobs were done with electrical work permits, and both
were inspected and passed. So I have done a bit of this before. But it
was a lot of years ago now, the code evolves, and my memory fades.

Roy Lewallen, W7EL

On Fri, 08 Aug 2003 10:05:43 +0100, Paul Burridge
wrote:

On Fri, 08 Aug 2003 03:29:47 GMT, Eric Immel
wrote:

Paul, are you asking if anyone has been killed, then revived?

That's pretty close to what I'm getting at. What I *am* actually get
at is that theoretical physicists are coming around to the rather
extraordinary view that one cannot from one's own perspective be
killed by any sudden and dramatic life event. No matter how bad the
shock, you will always 'come around' to find that you've survived. The
tricky bit is that you'll probably have found yourself in a different
reality to the one you left. In the one you've left, observers will
see your cold, dead, smoking body lying sparko on the ground. Your
relatives will grieve, your obituary will be written. But *you* won't
know anything of that. You'll just believe you've had a lucky escape;
you'll go home and tell your friends and family all about it and years
later maybe you'll tell others via the Internet. Sounds nuts?
Incredible as it may seem, the majority of physicists currently

Well that is funky!

Got electrocuted pretty well as a teenager. Fiddling about with an
ex-Army ZC1 set I'd converted to mains, managed to take 230vac from
arm to arm for what seemed like several minutes, but was probably a
second. Was sick, shaking, sore and sweaty for a couple of hours,
still had sore muscles for several days. Not at all funny. But the
universe I came back to seemed pretty normal.

Did the NDE thing after drowning in the school pool as a kid though,
can pretty clearly recall looking down on myself, and the teacher
"bringing me back" I suspect she still wanted to hassle me about the
unfinished homework, and drowning was not going to be accepted as an
excuse! Still the same universe though!

Barry Lennox

On Fri, 08 Aug 2003 10:05:43 +0100, Paul Burridge
wrote:

On Fri, 08 Aug 2003 03:29:47 GMT, Eric Immel
wrote:

Paul, are you asking if anyone has been killed, then revived?

That's pretty close to what I'm getting at. What I *am* actually get
at is that theoretical physicists are coming around to the rather
extraordinary view that one cannot from one's own perspective be
killed by any sudden and dramatic life event. No matter how bad the
shock, you will always 'come around' to find that you've survived. The
tricky bit is that you'll probably have found yourself in a different
reality to the one you left. In the one you've left, observers will
see your cold, dead, smoking body lying sparko on the ground. Your
relatives will grieve, your obituary will be written. But *you* won't
know anything of that. You'll just believe you've had a lucky escape;
you'll go home and tell your friends and family all about it and years
later maybe you'll tell others via the Internet. Sounds nuts?
Incredible as it may seem, the majority of physicists currently

Well that is funky!

Got electrocuted pretty well as a teenager. Fiddling about with an
ex-Army ZC1 set I'd converted to mains, managed to take 230vac from
arm to arm for what seemed like several minutes, but was probably a
second. Was sick, shaking, sore and sweaty for a couple of hours,
still had sore muscles for several days. Not at all funny. But the
universe I came back to seemed pretty normal.

Did the NDE thing after drowning in the school pool as a kid though,
can pretty clearly recall looking down on myself, and the teacher
"bringing me back" I suspect she still wanted to hassle me about the
unfinished homework, and drowning was not going to be accepted as an
excuse! Still the same universe though!

Barry Lennox

In article ,
(Bill Bowden) writes:

Watson A.Name - 'Watt Sun' wrote in message
...
In article , richard.p.henry@saic
mentioned...

"Tom Sevart" wrote in message
...

"WB3FUP (Mike Hall)" wrote in message
...
10KV to fire magnetron in counter battery radar. Took six marines to
stop
me from burying my screw driver in the chest of the asshole that
thought
it
would be cute to push the radiate button.

I remember hearing the story of an Air Force tech working on a 30' radar
dish. For some dumb reason, someone energized it and promptly
microwaved
him to death.

Some of these stories are hair rasing... and I'm too much of a weenie to
stick my tongue on a 9V battery...

A Raytheon corporate legend is that one of the engineers discovered the
microwave oven principle when a radar melted a chocolate bar in his shirt
pocket.

When I was in the army at Ft. Monmouth, NJ, we trained on a radar
trainer, had a klystron that put out 1W to the horn on the top of the
unit. We could put our finger over the horn and feel it get mildly
warm from the RF.

Big deal. The Real Thing put our 5 megawatts!

Sure, but the pulse width is only a microsecond, so the
average power is only 5 watts at one pulse per second.
I forget the rep rate of the one I woked on but at
6uS per mile and 400 miles round trip, the rep rate
would be about 400 Hz. So it's 400 times 5, or 2KW.

-Bill

A very rough estimate of "radar range" (time out to return of echo)
is 500 feet per microsecond. For a 200 mile search radar the time
out to echo return is 2+ milliseconds, depending on whether it is
calibrated for statute or nautical miles. Typical PRF for those 200
mile search radars was 400 Hz (PRT of about 2.5 mSec).

Average power output is Peak x ((pulse width)/(repetition time)) or
5 MW divided by 2500 = 2 KW.

2 KW concentrated in a 2 to 5 degree cone can have a devastating
heating effect on human tissue.

One may or may not be "in" the cone of the beam right up close
to the feedhorn but, with the construction of most search radars
(maritime or ground) there isn't much walk-around space to get
away from the feedhorn or the very close in-person effects of
microwave radiation.

When working on HIGH POWER RF at any frequency, believe in
the inverse square law and put as much distance from the antenna
as possible...or have a trusted person down on the power controls
who keeps the thing OFF while up there doing whatever.

I think it would be an interesting subject to compare peak power
RF effects versus average power RF effects. I can't seem to find
much on that in hundreds of pages of medical-biological reports
on the effects of RF radiation on human tissue. Unfortunately,
that has been pretty well shunted aside so that someone can get
their pet "alternate universe" speculations going on in here. :-)

All this gee-whizzy speculation stuff leaves me shocked.
But not fatally so...

Len Anderson
retired (from regular hours) electronic engineer person