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

[Bry Carling]

Dave,
I’m so sorry to hear that you got hurt. There are so many circumstances in which these things can happen when dealing with high-voltage. I was once working on my homebrew in your amplifier using to Dave,
I’m so sorry to hear that you got hurt. There are so many circumstances in which these things can happen when dealing with high-voltage. I was once working on my homebrew linear amplifier using two 4-400A tubes. Interestingly the B+ was also run through “variac.”   (For contest I could run it all the way up to 3200 V of necessarily but that would usually pop the diode strings! )

One day when I was working on it the power was turned off but it was still plugged in to the 220 V AC outlet.
While I was working on it my knee came in contact with the on off switch.

Not good. Got some burning on the back of my left hand. I hope the shaking feeling leaves you and everything heals up quickly my friend.

I’m grateful that you survived this.

Best regards - Bry Carling, AF4K





On Nov 16, 2019, at 2:34 PM, David Stinson <arc5 at ix.netcom.com> wrote:

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


______________________________________________________________
Boatanchors mailing list
Home: http://mailman.qth.net/mailman/listinfo/boatanchors
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Boatanchors at mailman.qth.net

List Administrator: Gary Harmon, K5JWK
** For Assistance: gharmon at idworld.net **


This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to af4k at hotmail.com