MFJ MFJ-1788 is a small space antenna that offers many capabilities. It is a convenient antenna for amateurs. The MFJ-1788 covers 7 MHz to 21 MHz. The antenna is only 36 inches in diameter and features an indoor semi-automatic tuning unit with a built-in cross needle wattmeter. The antenna element is constructed from thick walled aluminum pipe, making it durable and able to perform nearly as well as a full-size dipole. The MFJ "Super HI-Q Loop" antenna is easy to install and can be used for transmitting and receiving signals.