Re: Strike Rail Yes? No?

["Bert Hickman" <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: "Gregory R. Hunter" <ghunter-at-accucomm-dot-net>
> 
> Fellow Coilers,
> 
> What's the latest wisdom on strike rails?  Are they needed or not?  I'm
> asking because I have just begun work on my all new 6" x 30" Tesla coil,
> and I'm trying to decide if I need a strike rail or not.  I remember some
> postings awhile back suggesting that strike rails were old hat and no
> longer required.  This will be a "generic" coil of conventional design for
> use with various power supplies ranging from 1600VA of NSTs on up to 4 or
> 5KVA of pole xfmer input.
> 
> Best Regards,
> 
> Greg Hunter
> www.angelfire-dot-com/ga3/tesla

Greg,

Well, I still use a grounded strike-rail on my system. I have a 17 turn
primary that's tapped at about 15 turns. Early-on, while proving in the
system, I accidentally left off the ground lead to the strikerail. While
firing up the system, I got a number of hits from the torroid to the
floating strike rail, which then caused bright flashovers between the
strike rail and the outermost turn on the primary. I promptly lost one
of my 15kv 60 MA NST's. Coincidence??... perhaps. I subsequently
grounded the strike rail, and was able to operate for extended periods
with no problems for many months thereafter with countless direct
strikes to the strike rail. 

Now, I fully understand the theory and the technical reasoning behind
why a strike rail may not be necessary. And I've also heard the
anecdotal evidence from those running with no strike rail that they've
seen no problems, even after punishing runs to try to break their
system. However, based upon the anecdotal evidence I saw in my simple
"sample of one" test, I'm not going to remove the strike rail on my
system. Not using a strike rail will add about 2-3" of increased
striking distance between the toroid and the primary below, will
simplify construction, and will avoid the cost of a short piece of
copper tubing or wire. However, as with Accident Insurance, I view it as
cheap protection that I can afford to live with... even if I may not
need it.  Your mileage may vary! :^)

Safe coilin' to you, Greg!

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-com
Web Site: http://www.teslamania-dot-com