Re: 6" coil/PVC form

P.L.Mason-at-bath.ac.uk Wed Dec 13 07:12 MST 1995 wrote:
> Hi there
> I have been wanting to build a 6" coil using a length of pvc which I have had
> for some time. However, RQs instructions suggest that a) PVC is a poor choice,
> b) a lot of drying and sealing is required.
> I have access to a 5.25" length of plexiglass tube. Whilst the diameter is
> smaller, would I still get a coil which will be expandable (ie. usable with
> bigger power supplies)?

Sure.  A 5.25" OD secondary can be used at some fairly high power levels.  You should be able to 
pump 3-4 KVA through it, maybe more, without breakdown, if it is well built.  Is that enough 
power for you?  You didn't define what "bigger power supplies" meant.

> Also (to Richard mainly), if I use plexiglass, what shortcuts if any can I take
> with drying and sealing?

Shortcuts?  You'll be happy to hear that with acrylic, no drying or sealing is needed.  First, 
acrylic is not hydrophyllic (water absorbing), so no drying is needed.  Secondly, it is low loss 
in the RF band.  Because of these 2 factors, it needs no sealing before winding on wire.  Get the 
form and start winding.  The only sealing needed is on the wire after winding it on.

Scott Myers