VTTC operation, questions

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

Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sundog-at-timeship-dot-net>

    Hi All!

 Christmas is nearly upon us, with all the ritual last-minute shopping in
overcrowded stores elbowing your way past the checkout lines in a useless
attempt to find the shortest one.  Tip I learned last year, the shortest
line is that way because everybody in it moved to a faster line ;)

Now, the serious stuff!

    I've been digging through vacuum tube information, and am seriously
kicking around the idea of grid-modulating a VTTC.  Principle is identical
to a SSTC, you feed bursts of RF to the primary.  The 833A is well-suited to
this task, and works at full power up to 30mhz I believe, so it should work
fine at the 400-someodd khz range.
    The more I go through the schematics, the more sense they make (I'm no
EE, and tube gear is still funky to me).  There are some problems for me to
overcome, but with my tube-driven signal gen as a working example of a grid
tuned circuit, I think I can do it.

  Steps to this project :
 - Build a high-powered DC supply.  I'm acquiring the MWO's for this.  I
want about 3kv -at-1A available on a full-wave rectifier with a good-sized
resevoir cap.
-  Build the small grid-tuned oscillator.  The signal gen is going to be a
world of help here.

 I have the rest of the parts that I'll need (the push-pull VTTC primary,
etc.)  I don't forsee this project being a fast or easy one, but it should
be fun and educational.  Plus the 833's are "just a little more tolerant" of
mistakes than a MOFSET ;)  Most non-disastrous flaws show up as decreased
output and increased tube dissapation.  In all honesty, the driving system
for the 833's will be the most challenging.  Eventually I want to modulate
the preamp tubes with solid state gear for adjustable duty cycle and better
modulation control.



A note to all MOT scroungers, the few days after christmas are some of the
*BEST* days to find MWO's sitting on the curb.  A kind work and smile to the
old owner is usually all that's needed to get permission to retrieve it from
it's fate.  Curb-raiding is highly frowned upon where I live (guess how I
know?)

         Comments, questions, and snide remarks welcome!
                                                Shad