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

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Subject: [AMPS] Resoldering 3-500Z Filament Pins ??
From: measures@vc.net (Rich Measures)
Date: Mon, 5 Apr 1999 02:53:45 -0800


>
>>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.  

?  In this case, the amplifier was reportedly switched off when the fatal 
accident happened, so pulling the power plug would not have helped. 

>> 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. .......  

?  This is the first case I have heard of where a death was caused by the 
stored charge on a filter capacitor.  Heart defibrilator machines 
typically have an energy storage capacitor that would work quite nicely 
as the filter capacitor in an 8877's (FWB) HV power supply.  For an 
amateur radio operator who is having a heart attack, switching the 
amplifier off and discharging the HV filter cap. through his chest might 
very well save his life.  
>.......


Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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