CurrentForcing™ Baluns
Antennas & More CF Baluns are designed for matching antennas to coaxial feedlines. In addition to providing direct or transformed impedance relationships, CF Baluns contribute to the equalization of the currents in the antenna arms and impede the creep of antenna current down the outside of the coaxial feedline.

Key benefits of CF Baluns:
2 KW Rating
Flat 1.8 to 30 MHz Response
Current-Balancing Design
Mechanical Solidity
Black Weather-tight Case
Weather protected Connections
Commonly available impedance transforming Baluns exhibit two important limitations. First, they saturate easily if made on toroidal forms. More fundamentally, they don't force equal currents at their output and thus do not help preserve antenna and feedline current balance. Antennas More CF Baluns overcome these problems. You will find them to be robust and efficient elements of your antenna system. 

1:1 Ideal for Dipoles, Slopers, and Inverted-Vees. May be used for the driven element of close-spaced multi-element Quads, or any other antenna where the feedpoint impedance corresponds to the 50 ohm impedance of the coaxial feedline. By equalizing the currents in the antenna legs, the CF 11 Dipole Balun improves antenna pattern balance and impedes feedline radiation by helping prevent antenna currents from flowing down the outside surface of the coaxial feedline.

4:1  Ideal for matching Windoms, Folded Dipoles, and other antennas presenting feedpoint impedance's between 160 and 300 ohms to standard 50 or 75 ohm coaxial cables. Unlike common step-up Baluns the CF 41 Balun promotes balanced current in the antenna legs and impedes radiation from the coax feedline, producing a tame effective antenna.

Hint: How to Tame Zepp Feeders--Open wire (Zepp) feedlines and 450-ohm window line are light, inexpensive and efficient ways to feed multi-band antennas, but they can bring high RF voltages into the shack causing equipment to malfunction. There is a simple way to tame them. Bring them to the outside of the building, and at that point attach them to a CF 41 balun. Finish the run with a short length of coax to your tuner. Even at high SWRs, losses in the coax will be negligible since the run is short; so with no significant loss of efficiency this trick will help you keep high RF voltages out of the shack. Note: Many hams think that if they are using 450 ohm window line they should choose the  9:1 balun for the trick just described. The CF 41 is a better choice, however, for reasons of efficiency and wide bandwidth. 

3:1  Designed specifically for matching the feedpoint impedance of single loop multi-band quad and delta loop antennas to 50-ohm coax. It's exclusive transformation ratio was determined by experimentation conducted by G4EZG using OmniLoops and his Variable Radiation Angle multi-band loops in varying shapes and dispositions. LoopBalun comes complete with instructions for building your own multi-band single loop antennas. Rated 2KW.

In-LineTM 1:1 Feedline Baluns: When balanced antennas like dipoles are fed with coaxial cable, there is always the possibility that antenna currents will creep down the outside surface of the cable shield. Such currents flow around the outside cases of antenna tuners, radios, and power supplies, often finding their way into power and telephone lines through the utility ground connection. The result can be unpredictable equipment performance and unintended interference to television, telephone, and audio equipment. Antennas & More In-Line 1:1 Baluns prevent such flows and preserve antenna and feedline current balance.

Ordinary wire-wound 1:1 Baluns and Baluns that break up a coaxial feedline introduce impedance discontinuities and losses. Baluns wound on toroidal cores saturate easily. But Antennas & More In-Line Baluns are made with unbroken lengths of coaxial feedline surrounded by ferrite beads. By building the Baluns right into the unbroken feedline we offer you the most efficient 1:1 feedline isolation you can find,

Bead Balun Kits

Build your own in-line balun with one of these kits. Not difficult at all. Very quick and easy to do. Kit includes ferrite beads selected for maximum impedance between 2-30 MHz. Kit includes full pictorial instructions and all parts including protective cover to prevent bead breakage--everything needed for a successful job. The resulting balun is versatile and easy to change from one feedline to another, a great source of flexibility if you like to experiment with antennas.

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Last modified:  August 16, 2009