Re: [TCML] Form materials, losses, carbon tracking, sealing

[FutureT@xxxxxxx]

In a message dated 12/14/2007 4:21:41 P.M. US Eastern Standard Time,  
btmeehan@xxxxxxxxx writes:

>Thanks a lot for the info guys, that helps a lot - I heard someone  mention
>using concrete forms.  If I remember, those were made of  very thick
>cardboard?  Since I have heard several people talk  about it - I imagine that
>it is reasonably resistant to lighting on  fire when it gets strikes?

>I had been looking at a model rocketry  site that sells fiberglass forms, and
>even does custom work.   Would I be better off with cheaper PVC or concrete
>forms, or would the  lower loss tangent of fiberglass be worth something?
>(granted, most of  the loss tangent numbers I have seen are in the MHz or GHz
>region, so  kHz is probably not a problem with most materials)
>(loss  tangents)


I would avoid those paper concrete forms.  Some of them have  strange
lossy materials in them.  Some are OK though.  Losses in PVC  are
not an issue for Tesla coils, but they are subject to carbon  tracking
when bad racing sparks or flashovers occur.  Probably the most  common
material used for secondary forms is PVC.  Heating and sealing the  PVC
is said to be beneficial but I never bothered with those  procedures.  
My TT-42, and TT-32 coils both use PVC forms.  
 
  _http://hometown.aol.com/futuret/page3.html_ 
(http://hometown.aol.com/futuret/page3.html) 
 
John









**************************************See AOL's top rated recipes 
(http://food.aol.com/top-rated-recipes?NCID=aoltop00030000000004)
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla