[AMPS] Pencils and fiery inch-long arcs!

[Bob Sutton]

Good grief!!!  "DON'T TRY THIS AT HOME" is right!!!  I know you are
referring to RF voltages, but the cap of an 813 also has the HT voltage of
course.  Many years ago a ZL ham died when he used a pencil to tap a
stubborn relay contact in his amplifier that was carrying a very modest
level of HT voltage.  The pencil lead and pencil 'body' conducted enough
current through HIS body that HE is no longer current! 

Having experienced 900V across my chest from one hand to the other when I
build my first amplifier 22 years ago ... I still have a scar on my little
finger where it brushed the live component and blew a hole in the skin ...
I have always taken the utmost care (and a 'one hand in my pocket'
approach) anywhere near anything that could carry HT voltage.

73 ... Bob, ZL1RS

P.S. Richard.  I had an ETO Alpha 77Dx until recently  ... it was an
emotional time as I past it onto the new owner!
 
At 11:06 21/07/98 -0600, you wrote:
>
>As anyone who's ever [FOOLISHLY -- DON'T TRY THIS AT HOME!] used a pencil 
>to draw a fiery inch-long arc from the cap of anything bigger than an 813 
>can attest!
>
>Dick
>
>-----Original Message-----
>From:	Bill Turner, W7TI [SMTP:wrt@eskimo.com]
>Sent:	Monday, July 20, 1998 5:17 PM
>To:	Jon Ogden
>Cc:	Rich Measures; amps@contesting.com
>Subject:	Re: [AMPS] Vacuum Cap Rating and Plate Voltage
>
>
>On Thu, 16 Jul 98 14:35:10 -0500, Jon Ogden <jono@enteract.com> wrote:
><snip>
>>The handbook was correct as everyone told me: With a blocking cap the
>>peak RF voltage is equal to the DC plate voltage.  It's without a
>>blocking cap that you get the twice the DC voltage at peak.  So I
>>remembered incorrectly!
>_______________________________________________________________
>That figure of equal voltage is correct when the output tank is fully
>loaded.  With very light loading and lots of drive, the peak RF
>voltage can be MANY times the DC voltage, and that's when the tuning
>cap will arc.
>
>73, Bill W7TI
>
>
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