VTTC, sputter or not?

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

Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>" <srward16-at-hotmail-dot-com>

Ok,

Im torn between designs right now.  I find the simplicity in the standard 
grid leak coil design, to be appealing, but the tubes get red!  I have read 
that 811A should not show any color on the plate?  But i also heard the 
sputter mode can cause some kickback into the tube.  But then again the 
standard, grid leak, circuit users reported some flash overs inside of the 
tube.

So what circuit is better? I basically have parts for both types, and i have 
already gotten the grid block, sputter mode, circuit to work so im very 
tempted.  Does anyone know of a design that uses the sputter mode, but has 2 
seperate inductors on the primary, rather than the hartley design?  That was 
the major drawback to the original coil i built:

http://www.angelfire-dot-com/electronic/cwillis/811acoil.html

I did have this coil giving about 3.5" sparks consistently, and it would not 
color the tube unless i had the center tap of L1 set too high.
This coil was extremely difficult to tune since that there were 4 possible 
tuning points.  I also would like to get rid of that diode and filter cap, 
since Sue G. reported that raw AC made larger sparks with her coil.

So if anyone could help me out with a general circuit for a sputter with 
seperate inductors, coil, i would really like to hear about it.  I did find 
this:

http://chaoticuniverse-dot-com/webdoc2.htg/Tubez.htm

But with my coil i could not possibly use that large of a primary 
cap(diagram shows 2.4uf!!  could this be nf?), or such a large filter cap.  
And the max for my grid block cap could only be .09uf.  But really what is 
best, a high sputter frequency or lower?  Which would have less duty cycle 
on the tube?  what are the pros and cons regarding this?

So is it correct to assume that grid block coils need to be fed B- to the 
cathode via a diode?  Or can you use AC and let the tube rectify and still 
use a grid block circuit.

This is about all that i can think of to ask at the moment(i know its alot). 
  I just want a design thats not going to really cut down the tubes life.  I 
also liked the grid block design because it only seemed to stress the 
primary cap, but now i have really massive caps, so it shouldnt be a 
problem.

Steve Ward.