[Amps] Decline of homebrewing?

[Arthur Movius]

I heartily second Ward's words and Jim's advice.

Every one of the legal limit tube amps that I built incorporated 
interlocks.  The first amp used a free TV station's timed out 4-1000A.  
It was built per the 17th ed. of William I. Orr, W6SAI's /Radio 
Handbook/, page 682.

My dad became a SK at the age of 64 when he put the cover back on his 
amp, right after shutting it down.  Arc marks indicated that the cover 
contacted the top of the plate choke.  Burn marks on dad indicated that 
the current path through him was from both hands which were holding the 
cover to his abdomen which was touching his mike.  Although voltage was 
bleeding off, there was sufficient energy in the voltage doubler power 
supply caps to cause muscle reaction that sent him backwards about 6 
feet and kill him.

When working around exposed HV a second opportunity to make a mistake is 
improbable.

73, Jim, K7AJM


On 1/7/2017 9:14 AM, Ward Silver wrote:
> > Excellent advice, Jim.
>
> Hear, hear!
>
> And another good piece of advice is to make sure you have an ac safety 
> ground connection on every metal enclosure.  With 12 Vdc being the 
> normal power supply voltage these days, we can get away with practices 
> that would really be hazardous for tube-based gear.
>
> >  A 50 uF capacitor charged to 4000 V holds a potentially deadly 400 
> Joules of energy
>
> In the defibrillator business of a few years ago, this was known as 
> the "rescue shock" of last resort.  This amount of energy can lift a 
> 200-pound person 1.5 feet.  When leveraged by muscle-and-bone, much 
> damage can be done.
>
> 73, Ward N0AX
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps