[ARC5] A WARNING: The Death Angel Flies Close.
David Stinson
arc5 at ix.netcom.com
Sat Nov 16 14:34:34 EST 2019
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
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