Re: Racing arc clues...

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

Original poster: "Robin Copini by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rcopini-at-merlin-dot-net.au>

Hi Terry,

 I am very interested in this thread as I have been dogged by this regularly
since building my coil from day one. I have found that I can run my unit at
almost any power level on one day with perfect results, pack it up, set it up
again on another day in exactly the same place, same rf grounds, the power
supply is still where I left it, and then get racings arcs up and down the
secondary. I always wipe down the secondary, topload, and primary with a cloth
before running. What I usually do to rectify this is to either slightly raise
the secondary, or close down the gaps, (even though its a sync rotary, I still
vary the gap size). Note that the tuning point does not change from one day to
the next. I have some still photos of these arcs and they tend to start
roughly one third from the top and either arc straight down the secondary or
arc across to the strike rail. I have seldom seen these arcs originating from
near the top windings where one would assume the highest potential is.

just my two cents worth.

 Best Regards

 Robin Copini.




Tesla list wrote:

> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
> Hi All,
>
> We are working on racing arcs on the TSSP project.  Here is an interesting
> point during the secondary ring up for a k=0.12 and k=0.20 situation:
>
> http://hot-streamer-dot-com/temp/Vgrad.jpg
>
> The differences are sort of subtle but many clues are being noted.
>
> I was wondering if having the secondary "clean" as opposed to being dusty
> or dirty made racing arcs worse?  I am thinking that dirt would make
> ionization do to rapid voltage changes more likely.
>
> I also know that "over coupling" and "mistuning" are factors.  Are there
> any other consistent things that have an bearing on this?
>
> Where do racing arcs tend to occur most?  I have often heard near the base
> of the coil but I think they sometimes appear near the top.  It 3rd
> harmonics are a factor, that may make some sense.
>
> Still many unknowns but looking for more clues...
>
> Cheers,
>
>         Terry