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Title: Homebrew coil question Post by: AB1GX on March 17, 2007, 04:28:04 PM In power supples, it's common to see multi-strand wire or copper ribbon inductors to reduce AC resistance (skin effect) rather than solid copper wire.
With this in mind, would an aluminum ribbon inductor .025" thick by 2" wide with a 9" diameter for operation at 3.8MHz be as good as a 1/2 copper pipe inductor with the same 9" diameter? The inductor is for the resonate output in a 1.5 KW 75 meter AM transmitter. Title: Re: Homebrew coil question Post by: AB1GX on March 18, 2007, 10:15:27 AM In my testing so far, it looks like a 'cure' for hot output inductors is using flat wire (ribbon) rather that solid round. I didn't try tubing since it has significantly more interwinding capacitance and makes modeling much more difficult.
I'll bet aluminum is just as good as copper if the ribbon is made wider to account for Al's higher resistance. Title: Re: Homebrew coil question Post by: David, K3TUE on March 18, 2007, 02:19:50 PM Isn't the coil in a Johnson kW Matchbox made of flat/wide ribbon-like material. Not as you described in your question, but more so than the Johnson (250) Matchbox.
Title: Re: Homebrew coil question Post by: WA1GFZ on March 18, 2007, 09:40:34 PM Tubing works fine as long as you space turns with one diameter air gap to get the best Q. EDGE wound allows closer spacing. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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