The MFJ-911 is a true 4:1 current balun/unun designed for indoor use. It uses large lowpermeability ferrite cores to transform 200 ohm balanced or unbalanced loads to 50 ohms, and is rated at 300 watts with relatively flat response from 1.8 to 30 MHz. Its SO-239 coax connector has Teflon™ internal insulation for maximum insulation and extended life of the product. 2-way binding posts provide for convenient hookup.
A current balun can reduce or eliminate stray RF often found on coax. This stray RF can cause burns and other problems with electronic equipment while reducing antenna radiation. Installation of an MFJ-911 balun can increase the efficiency of any amateur station.
The MFJ-911 measures 2½ x 4¾ x 1 inches.