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Re: Tube identification help (833)



At 05:30 AM 2/26/99 , you wrote:
>Original Poster: "Edward J. Wingate" <ewing7-at-frontiernet-dot-net> 
>

>David,
>
>It sounds like you have gotten your hands on a pair of 833C's which have
>a carbon/graphite plate and will take a great deal more abuse in Tesla
>coil use than will the standard metal plate 833A's. Nice find! You now
>have two perfect reasons to start on that tube coil!
>
>My vacuum tube coil uses a pair of 833C's and produces approximately 24
>inches of spark with an input of almost 7 KW.... VTC's are very
>inefficient. Even at this power level the plates on the 833C's will
>barely glow red after continuous runs of 2 minutes or more. Just a
>single 833C on this coil will produce 20" of spark with the plate
>glowing a dull red. The limiting factor of this coil with both tubes
>connected is the physical size and spacing of the primary/secondary....a
>condition which I have not taken the time to rectify yet.
>>snip<>>
>Happy VT coiling,
>
>Ed Wingate RATCB
>

Hey thanks everyone for the replies. And yes I am very happy about my
finding those tubes for such a reasonable price. This evening I have been
testing various configurations using those tubes along with my new
transformer and the Panasonic caps. My results, as far as spark, were
dismal, but I already new that I must redesign all. But first I would like
to say the Panasonic caps are great, they do not heat up greatly, causing
the tank capacitance to stray, as do the doorknobs. I am using 10 of the
0.015-at-1600VDC Polyprop ones strung in series, set so I can tap the last
three caps. I was running 4000 VAC to the Tank/plates and pulling about 20+
amps into the trany, and let it run for five minutes (producing a 10-11"
discharge), the plates on the tubes were just starting to get cheery red at
the end, and the Panasonic caps were just warm to after I powered down. So
I would indeed recommend them in Tube coil service, but for a gap coil one
needs a cap that can take some major abuse.

Regards,

David Trimmell