Re: Early versions of Tesla's coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <teslalist-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
 >
 > Original poster: "davep by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<davep-at-quik-dot-com>
 >
 > >It is very possible Tesla himself designed and maybe
 >
 > >constructed vacuum tube Tesla coils.
 >
 >          The three electrode vacuum tube had not yet been
 >          invented when Tesla was working (say: pre 1905).
 >          If Tesla sketched out use of vacuum tubes later,
 >          I am unaware of any record surviving.  At The
 >          Time (pre 1910) generating even a watt or so with
 >          Vacuum Tube techniques was the limit.  By the end
 >          of WWI, with Major Effort a KW or so was doable,
 >          with Massively Parallel banks of tubes.  For
 >          (typical) TC freqs spark, arc, or even direct
 >          alternator were the way to go for KW +/-
 >          power range.
 >
 >          best
 >          dwp

	There were more powerful tubes used during WW1 and someone who had
scrounged some (an awful lot of hams had "surplus" military tubes which
they must have liberated while in the service) could have built a decent
VTTC even then.  One "250 watt" tube type which reappeared commercially
in 1921 was the RCA UV-204. Used in some transmitters as a self-excited
oscillator with 2000 volts AC on the plate, pretty close to what an MOT
will do.

Ed