Did you open up a Cushcraft balun to discover that method? I believe some other companies do similar and Teflon wire is used so it doesnt char as does THNN.
Carl KM1H ----- Original Message ----- From: "Jim Brown" <[email protected]> To: <[email protected]> Sent: Tuesday, August 30, 2011 10:33 AM Subject: Re: Topband: Fabricated common mode chokes - Sourcing >A year or two ago, based on the experience of some hams in the UK who > found Fair-Rite cores either impossible to obtain or very expensive, I > did some more experimental work that resulted in designs for > transmitting chokes that can be wound on a single #31 core, be very > effective from 80-10M, and handle at least 500W with antennas that have > reasonably good balance. If the antenna is well balanced the choke can > handle legal power. > > The new designs use bifilar windings -- that is, two conductors taped > together and wound around the core that function as a parallel wire > transmission line in place of coax. An alternative design uses more > turns and covers 160-15M. These designs were added to my RFI tutorial > last summer (June 2010). The best of these designs use ordinary "house > wire", known in North America as THHN. > > The tutorial is http://audiosystemsgroup.com/RFI-Ham.pdf > > 73, Jim Brown K9YC > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1392 / Virus Database: 1520/3867 - Release Date: 08/30/11 > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
