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Go back to the bottom and start winding a second pair, again going from the top of the toroid, but this time winding in a COUNTER-CLOCKWISE direction. After 1 turn, clamp the wire to the core with another cable tie. Finish with 7 total turns and secure with a cable tie. Refer to Sevick's photo 2-E (or 4-1a_nøss.jpg, next page).
Build a High Power 4:1 Guanella Current Balun RF Choke and Transformer Using 2 Cores. As with the 1:1 Balun, there’s plenty of online info on building 4:1 Baluns. I’ve seen and read many articles on baluns and there’s’ plenty of pretty variable advice out there.
Baluns and Ununs”). Label the 7-8 lead as RED (colors correspond to the approximate colors of the wires used in the R/S #24 speaker wire (278-1509), label the 5-6 lead as White, 3-3 as RED and 1-2 as WHITE. Cut off around a 18″ of the paired wire. Refer to Sevick’s photo 2-E (or the 4-1a_n0ss.jpg file accompanying this write-up), left side of
The easiest way to start building a 4:1 current balun is to order the AB240-250 K Mix Balun Kit from Amidon Associates. This kit includes the proper toroidal core, 12.5 feet of #14 magnet wire, 12.5 feet of Teflon tubing, and the Transmission Line Transformer Handbook 2 by Jerry Sevick, W2FMI.
One popular UnUn and Balun handbook shows a lack of understanding of how to analyze, measure, and test baluns! It actually suggests power is evenly divided between the two choke baluns making up a 4:1 current balun. Nothing is further from the truth!
Requiring a balun to feed a balanced feed line with an un-balanced T-Match network a 4:1 Ruthroff voltage balun design using a T200-2 Toroid core was selected. While the 4:1 ratio is often referred to for the interface between T-Match network and a balanced antenna system it will often not be the ideal choice when very low impedances are encountered.
Vertical or Horizontal Loop: The best balun for operation moderately far from resonance or on harmonics is a 4:1 ratio current Tuner Balun. The DX Engineering part number of the correct balun would be the DXE-BAL200-H10-AT or the DXE-BAL200-H11-CT depending on power levels and operating environment.
