[SOC] Re: [autotrax] OT _ TO-220 proper installation?

[Mike Besemer (KG8L)]

Being a lefty, I'd no doubt electrocute myself if I kept my left hand in my
pocket and tried to work with my right!

The premise, however, does have merit.  When I was working on aircraft
radars during the 80's and 90's, we always practiced the 'keep one hand in
the pocket' thing.  We were also forbidden from wearing any combat boots
with nails in the sole or with steel toes.  

We also had mats in front of all of our benches which had to be tested for
electrical conductivity (actually...lack thereof) every 90 (I think) days.  

Every now and then, some eager-beaver young airman would decide that the
mats looked bad and would clean them with 409 (or a similar cleaner), and
then wax them.  The mats did look very nice after this treatment, but it
also caused them to take on a conductivity of less then a megaohm, which
meant they had to be replaced.  (I think the 'passing' standard was 10
megaohms between 2 points 12 inches apart, measured with a Megger).

In 17 years of working on the bench, I never took a good jolt across my
chest.  I had plenty of zaps from finger to finger of the same hand (darn
pinkie always got in the way), and a few from finger to elbow or finger to
knee.  Most of the stuff we had was pretty tame... Maybe a max of 25KV
pulsed (which still hurts like hell when it goes in one finger and out the
next).  

We had a couple of systems that just had a habit of 'reaching out and
touching someone'... Usually to the tune of about 250 VDC.  Funny thing
about DC... It tends to make you tighten your grip on whatever it is that's
trying to kill you.  AC and pulsed currents generally tended to throw you
clear!  

We had one fellow who got across the pulse network of a radar transmitter...
About 10600 volts pulsed.  He landed about 8 feet from where he had been
standing.  He was uninjured (except for his pride), but he managed to bowl
over another guy who was working nearby.  The bystander had to go to the
hospital for stitches where the stool the first guy had been sitting on
whacked him.  The next day when we came to work, we found that the night
shift had taken masking tape and labeled the floor... (250 VDC impact point,
500 VDC impact point, 1000 VDC impact point)... Etc.  Darn near as funny as
the guy who used to like check to see if his soldering iron was hot by
sniffing it.  Funny thing about that guy... He never DID have any nose
hair...

72/3/4,

Mike
KG8L
SOC # 169 

-----Original Message-----
From: soc-admin@mailman.qth.net [mailto:soc-admin@mailman.qth.net] On Behalf
Of Derek Wills
Sent: Sunday, February 22, 2004 12:27 PM
To: soc@mailman.qth.net
Subject: Re: [SOC] Re: [autotrax] OT _ TO-220 proper installation?

> Personally, when fault finding equipment with high potentials involved 
> I use the technique taught to me by an old WW2 radar technician. Wear 
> rubber soled footwear and always keep one hand in your pocket (preferably
your left).

      Why the left??   Does this only apply to those of the right-
      handed persuasion?   Or is it to do with the location of the
      heart?

      And don't people look at you suspiciously when you do this?

Derek aa5bt (#294 - I think).
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