[AMPS] Resoldering 3-500Z Filament Pins ??

[Jon Ogden]

>My dad, W7IWW became a silent key because of the error of not waiting long
>enough for the power supply volts to bleed off after turning off the amp
>which he had been operating with the cover off.  He was putting the cover
>back on and the cover in his hands contacted B+ plate choke while his tummy
>contacted his mike to complete a circuit through his chest area.  Instant
>death resulted.
>My thought is make your procedure "Murphy Proof" such as by watching the
>plate voltage meter after turning off the HV, using a  "crowbar",
>disconnecting the power source, etc.  Take your time- better to be late in
>this world than early in the next.
>I am glad those telling their experiences are around to tell them.
>Best wishes to all,
>Jim, KL7EGO

A sad story indeed.  Sorry to hear about that.  But you bring up a good 
point.  HV filter caps can contain a significant voltage for quite a 
while even with bleeder resistors.  The KV range meter might look like 
zero or nearly, but you can still have several 10s or even hundred volts 
there.  It can take quite a while for all that voltage to bleed off 
through the bleeders.

Another thing is bypass caps inside the amp cabinet.  I had been doing 
some HV experimets with the amp w/o the anode line being hooked to the 
tube for some reason.  I had shut the HV off and unhooked it from the amp 
cabinet once the filter caps dropped far enough. One thing I forgot about 
were my big bypass caps.  When I went back in and touched the anode line 
I got a nice zap as well.  So ALWAYS, ALWAYS short your bypass caps, 
anode line, etc.  As Graham said it's better to break something inside 
the amp than break yourself.

If someone else can learn from my stupidity, I guess I have helped 
humanity!

73,

Jon
KE9NA


-------------------------------------
Jon Ogden
KE9NA

http://www.qsl.net/ke9na    <--- CHECK IT OUT!  It's been updated!!!!!


"A life lived in fear is a life half lived."


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