[Amps] Forms for air wound coils

[Larry Benko]

Looking at the continuous air service temperatures for common plastics 
shows Teflon = 500F and PEEK = 480F and amazingly Polycarbonate (Lexan) 
= 475F.   I usually use PEEK as I can get scraps from a local plastic 
dealer and it is hard and drills great. You can drill 2 rows of holes 
spaced at the turn spacing and separated by the diameter of the coil.  
Offset the 2 rows by half the coil spacing.  Then wind a coil on a 
slightly smaller form and then thread it on to the drilled form.  It is 
pretty easy to do.

73,
Larry, W0QE
On 7/23/2012 2:38 PM, Gudguyham at aol.com wrote:
> Other than ceramic, can anything else be used as a coil form?   Heathkit
> used a fiberglass form in the SB-220.  At least I think it was  fiberglass.
> Seems to have worked OK.  Dentron used what looks to be  some type of
> phenolic material.  Not really sure what it was.   Anything out there that can be
> used that does not cost an arm and a leg?  I  am looking to make a coil for
> RF about 1 1/2" to 1 3/4" dia about 6" long. Not  to be used for plate
> chokes. Lou
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