From: John Woodgate
Subject: Re: low loss transformer availability?
Date: Mon, 6 Jan 2003 15:03:31 +0000
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Mon, 6 Jan 2003 18:33:41 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Winfield Hill
wrote (in ) about 'low loss transformer
availability?', on Mon, 6 Jan 2003:
>> Winfield Hill wrote
>>> For example, learning from Jerry Sevick, I designed a wideband
>>> 16x transformer (RIS-294) that worked in two stages. First 50
>>> to 12.5 ohms with 25-ohm coax, finishing with 12.5 ohms to 3.2
>>> ohms using 6-ohm transmission line, made from two wide copper
>>> strips insulated with a thin layer of Kapton tape. It handled
>>> over 100W, was flat from 500kHz to well over 50MHz, and could
>>> deliver over 10A peak into a 3-ohm load.
>> What I had in mind was how long the cables would have to be to
>> work at 3 MHz. '500 kHz' makes the answer even more interesting.
> Not so very long, if one uses a large high-permeability core.
> 'Course that can hurt on the high end. But I have found that
> a 100:1 frequency range usually isn't too hard to achieve.
CORE? You must mean something very different from what is in my mind. If
you wound the cables on to a toroid, how did you do that with the 6 ohm
line? "With great difficulty" is not an acceptable answer. (;-)
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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