Hy-Gain LJ-203BA 20 Meter Long John HF Monobanders are optimally spaced, 3-element 20M beam antennas. Their Beta-Match tuning ensures a maximum transfer of energy from the feedline to the antenna. Long John 20M beams are recommended to mount on a 2 in. to 2 1/2 in. O.D. mast and can be rotated with Hy-Gain CD-45II or HAM-IV rotators. These antennas include stainless steel hardware for all electrical and most mechanical connections. Taper-swaged seamless aluminum tubing is used throughout the antennas for maximum mechanical reliability. Stainless steel tubing clamps are used at the element joints for the best possible mechanical connection. Hy-Gain 3-element 20M Long John beams antennas are designed for use with 50 ohm coaxial cable, RG-213/U cable being preferred for its lower losses and higher power-handling capabilities. A choke balun is required to prevent unbalanced current from flowing down the transmission line and affecting the efficiency of the antennas.