[TCML] large secondary tubes ...

[FutureT at aol.com]

In a message dated 11/18/2007 2:47:17 P.M. US Eastern Standard Time,  
btmeehan at gmail.com writes:

Have you  guys ever considered fiberglass or carbon fiber (I think carbon
fiber is  probably too conductive for anything to even consider) - I have a
friend  who is into large model rockets and he has some experience with
making  fiberglass tubes, but I think that even fiberglass might  have
problems.  I was going to find out how good it was for RF before  I invested
any time/money into it.



For a spark gap TC, the RF losses in the secondary form tend to be
insignificant even with a hygroscopic material such as PVC.  The  biggest
problem with PVC is that it can carbon track.  Usually this is not a  problem
however.  If two coils are built, one using PVC, the other using  polyethylene
or polypropylene, no difference in spark length will be seen.  PVC,  
fiberglass,
or lucite tubing all work well.  Some coilers heat their PVC with  heat lamps
to drive out the moisture, then coat it inside and out with a sealer.  
 
John



************************************** See what's new at http://www.aol.com