[ARC5] [Boatanchors] A WARNING: The Death Angel Flies Close.

[Brian Clarke]

Hello Dave,

I am glad you are over the shock.

However, we need to be aware of how the human body responds to electrical insults. 1800 V is sufficient to overcome the resistance of your skin and allow some current to flow to give you an electric shock. Had your hands and whatever else was part of the conduction path been dry, the resistance, say between your hands, would have been around 3 to 5 MegOhm; the current flow, at worst, would have been about 0.6 mA; that is enough to give you a belt, a sharp shock, even. Were your body parts in the conduction path wet enough to have made electrolytic solutions of your body surface salts, the resistance could have been as low as 1.5 k Ohm; the current flow could have been up to about 1.2 A, depending on the power supply's capability; that would have resulted in deep-tissue burning, up to enduring and possibly permanent damage. But, it would not have killed you. For electrocution to occur, the current needs to be around 12 mA; then your heart goes into fibrillation and you have between 2 and 4 minutes before brain death and non-resuscibility. Defibrillation with about 30 seconds usually results in total recovery.

These results are much the same for all living animals. Your survival had absolutely nothing to do with god. It was the result of millions of years of genetic development of the mammalian genome.

Next time, keep one hand in your pocket.

Cheers es 73 de Brian, VK2GCE

On Sunday, 17 November 2019 6:35 AM, you said:

A WARNING:  Close Encounter with the Death Angel.

Some of you may remember an article I wrote some years ago, "Shockless," 
which was published in an Australian ham publication.  The point was how 
our focus and attention decline as we age and the great danger of 
working with High Voltage where a momentary mental lapse or getting 
out-of-order in our safety procedures can have tragic consequences.   
The article presented alternatives, like much-lowered B+ voltages, which 
can bring our old boatanchors alive without excess danger.  Well, I've 
just had The Death Angel pass so close I could feel his cold, fetid 
breath and the icy wind from his black wings.  It's only the grace and 
goodness of The Lord that I am here to write you this warning.

As most of you know, I'm working on a WWII Navy GO-9 transmitter and the 
project is nearing completion.  The power supply for this transmitter 
produces 1400V and 540V under load.  When unkeyed, the B+ is near 
1800V.   This level of voltage, if contacted across the body, is almost 
always instantly fatal.   I've been very careful to go slow, remember 
safety, have a sequence for power-up and power down.  Checks and 
rechecks before putting a hand in there. And it worked.  Until a moment 
of inattention and a neglected safety check, when it didn't.

I've had the High Voltage fed from a separate AC primary through a 
variac while tuning and testing.  When plugged directly into house 
current, the Low B+ is too hot (800V), so I was working on toning it 
down.  Got that all sorted out, so power down to make a couple of 
changes.  Turn off the variac.   Turn off the Filament supply. Wait for 
the resistors to bleed-away the charge, (**but neglected to check the Hi 
B+ voltage test point**).  The "B+ ON" warning light was facing away 
from me.
Just one thing my old, distracted brain forgot:  The Hi B+ wasn't 
plugged into the variac- my soldering iron was.  The Hi B+ was plugged 
into the house current, fully live, sitting at 1800 V like a coiled 
rattle snake.  "Looks like one of the B+ feed wires is a little too 
close to ground.  I"ll just move..."

WARNING:GRAPHIC PHOTOS
https://photos.app.goo.gl/9NLRVGj93NpSBgdB6
https://photos.app.goo.gl/C4KycfbxKhTYLLre9

Flash and bang.  If my other hand had been on anything conductive, of if 
I were on a concrete floor instead of a wooden deck, I would not me 
writing this.  I would have been instantly killed.  Worse, I would have 
left an deadly rattle snake, coiled to bite the family member who found 
me.   The burns on my left hand  look superficial, but my hands won't 
stop shaking.  The pain is pretty intense.  There is likely some nerve 
and deep-tissue damage; that will be evident over the next few days.   
The Lord God, in His mercy, decided to let me continue to draw breath, 
and I prayed my gratitude to Him for sparing me another day.
  But one does not get-away with such stupidity unless one is in 
Congress, and I ain't.

I am going to finish this project; it's too close now to give up on it.  
But DIrty Harry's advice echos in my empty head:
   "A man has got to know his limitations."
Have had close calls before, but nothing nearly so deadly as this.  Such 
Voltages are "a young man's game."  I think I've just had my last 
warning.  I simply no longer have the mental sharpness essential to deal 
with such danger.   I will never again take-on any project that requires 
such voltages.  I dearly love reviving these historic and beautiful 
rigs, but not enough to die for them.  All my pending projects that 
require this sort of voltage are going away.  All my iron at this level 
will be given away.
 From now on, I'm a "little rig" sorta guy.  Got no more room for big 
rigs anyway.

Be smarter than me (not very hard).  Be safer than me.  Don't do this.
And thank The Almighty for every new day.  You never know when it will 
suddenly end.

GL OM ES 73 DE Dave AB5S