BTW, Jim I assume that 18:1 is the impedance ratio, and the turns ratio is of the order of 4:1 or so
Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, August 05, 2013 2:04 PM To: BY THE LAKE; topband@contesting.com Subject: Re: Topband: best core material? Sorry - didn't make it crystal clear that this is a Delta shaped variant of a EWE antenna!!!! My bad for not utilizing all of the necessary verbiage to make that clear....you see it in ON4UN's latest book on page 7-104. > From: ma...@isp.ca > To: rodenkirch_...@msn.com > Subject: Re: Topband: best core material? > Date: Mon, 5 Aug 2013 14:00:48 -0400 > > A full-wave delta loop would have the transformation done with a 1/4 wave > line of 75 ohm cable. This must be something other than a full-wave loop? > > Bill VE3NH > ----- Original Message ----- > From: "James Rodenkirch" <rodenkirch_...@msn.com> > To: <topband@contesting.com> > Sent: Monday, August 05, 2013 1:33 PM > Subject: Topband: best core material? > > > > > > I have a schematic for a delta shaped loop that shows I'll need an 18:1 > > transformer to transform the 950 ohms of the antenna to 50 ohms (feeding > > it with 50 ohm coax). > > > > One transformer diagram shows an FT-140-43 core being used. > > > > BUT, looking over some of Tom's, W8JI, write-ups, I see where he uses 73 > > material instead. > > > > I see where 77 material replaced 73 material so -- is an FT-140-77 the mo > > betta way to go? > > > > > > Thanks, in advance, for any advice/info. Jim Rodenkirch K9JWV > > > > > > > > _________________ > > Topband Reflector > > > > > > ----- > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 2013.0.3392 / Virus Database: 3209/6552 - Release Date: 08/05/13 > > > > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2013.0.3392 / Virus Database: 3209/6552 - Release Date: 08/05/13 > _________________ Topband Reflector _________________ Topband Reflector