This vertical antenna is designed for operation on 10, 15 and 20 meters. It is designed to work against earth ground or a radial ground system. When used in conjunction with a resonant radial system, the vertical antenna becomes very efficient with a low angle of radiation and excels in DX communications. A simulated radial ground system (Model 14 RMQ, Order No. 184) is available from your Hy-Gain dealer. This manual tells you how to construct your own radial system. The 12AVQ-S now features stainless steel hardware for all electrical and most mechanical connections. NOTE: If you mount the antenna, then find the roof space is too small for the radial system, you can droop the radials over the roof at almost any angle without seriously changing the performance of the antenna.