What configuration of radials will match an elevated quarter-wave vertical antenna to a 50-ohm coaxial cable?

An elevated quarter-wave vertical antenna with perfectly horizontal radials typically has a feedpoint impedance of around 36 ohms. If you connect this directly to a standard 50-ohm coaxial cable, you will have a slight impedance mismatch, resulting in an elevated SWR. To raise the feedpoint impedance closer to 50 ohms, the radials can be bent downwards, usually at about a 45-degree angle. This configuration changes the radiation resistance and provides an excellent match to 50-ohm coax. The radials must remain a quarter-wavelength long to properly form the missing half of the antenna system; half-wave radials would present an excessively high impedance.