[Amps] Rf choke coil form

[Jim Thomson]

Date: Thu, 31 Jan 2013 14:46:52 -0600
From: George <at6c at bellsouth.net>
To: amps at contesting.com
Subject: [Amps] Rf choke coil form

I need a recommendation for a material to use in a coil form for an RF 
choke. The existing choke is about 1.5" diameter by 4" long. I would 
like to use ceramic but I can't find anything in this size, also what I 
have found is really expensive. Recommendations?
73,
George
W2GS

## Go to your local plastic shop.  I have used both solid delrin rod  and and also solid teflon rod.
You can get either in any diam you want.  Then drill and tap dead center, at the base to hold to chassis.

Drill a transverse hole about 1 to 1.5 inchs up from the base.  And another transverse hole just down  a tiny bit from the top. 
Insert brass machine screws into both transverse holes, and use double brass nuts etc.  You can wrap your magnet wire to the threads
of the brass machine screws and solder em at each end of the choke.  Then use small ga wire with crimped + soldered sta-kon ring
connectors ..and install the ring terminal between the double nuts.   Then you have an easy way to wire the choke at both ends. 

Glazed ceramic will also work, provided it is tapped at both ends.  G-10 hollow fiberglass tube will also work, but with any hollow
tube, you need a clamp, like a capacitor clamp to hold it to the chassis.    You can also buy hollow teflon tubing. 

Later... Jim   VE7RF