[Amps] Winding Large Inductor

[Rich & DJ]

-----Original Message-----

Date: Tue, 20 Nov 2007 13:22:26 -0800
From: Dennis Ashworth <K7FL at arrl.net>
Subject: [Amps] Winding large inductors
To: Amps at contesting.com
Message-ID: <200711202122.lAKLMQdE016155 at ashworth.org>
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I need to construct a 35uH air inductor using .250 copper tubing. D 
is around 5"; L = 10 inches. I can play with the dia & L a bit and 
still be in the Q ballpark I desire.

Does anyone have a jig or technique they use to make such a coil 
while maintaining the turn spacing and not kinking the tubing? It 
needs to be "pretty" because of where it will be located :-)

Thanks
Dennis, K7FL



 Dennis , 
I wind coils all the time and make jigs and forms for them. I also make
Tesla Coils but most of them are flat coils and forget about the sand and
other ideas. They are all good ideas for working the various types of tubing
but not needed for what you want. I have used up to 3/4 SS but that is
another story and a large lathe. Go with the refrigeration tubing that has
been bought up by several people. It is easy to work with right off the roll
, it will be soft and easy to work with the first try. It get harder with
each time it is flexed.
If you need more information on coil fixtures email me direct and I will
send pictures and notes on how to build you own. For what you want you might
need a form to prevent sag in the middle for either a vertical of horizontal
at 10" with 1/4 tube.  K8RI is right on with his notes also.

 Rich , Kd0zz