The MFJ-935B Small High-Efficiency Loop Tuner is a versatile and compact solution for amateur radio enthusiasts seeking to enhance their transmission capabilities. By simply draping a wire around a bookcase and connecting both ends to the tuner, users can create a small, high-efficiency multi-band transmitting loop antenna. This setup allows operation across a frequency range of 5.3 to 29.7 MHz with a maximum power output of 150 Watts, eliminating the need for ground, radials, or counterpoises. A 13-foot wire configured into a loop is effective for 30-20 meters, while shorter lengths cater to higher frequency bands.

One of the standout features of the MFJ-935B is its ability to tune loops of various shapes, including circles, squares, and rectangles. The most efficient configuration is a quarter wavelength wire shaped as a circle. Users can expect a frequency coverage of approximately 1.5 to 1 based on the wire length and loop shape. This flexibility, combined with the proven performance of high-efficiency small loop antennas, allows operators to achieve low-angle DX signals that can compete with full-size dipoles, making it an excellent choice for working incredible DX.

The tuner is particularly well-suited for portable operations, whether in apartments, hotel rooms, or during outdoor activities like camping. Its compact design, measuring 6 ¼” W x 9 ½” D x 5 ¼” H, includes an Easy-Carry handle for convenient transport. Additionally, the built-in RF Antenna Current Meter with adjustable sensitivity simplifies the tuning process for maximum radiated power. For those looking to create a self-contained antenna system, the MFJ-935B is compatible with separate PVC Cross Loop Antenna Kits, further enhancing its usability in various environments.