Calculate dimensions for popular amateur radio antennas
The most common antenna in amateur radio. Total length is approximately half wavelength, split into two quarter-wave elements.
Fed at a point offset from the center (typically 33% or 43% from one end). Provides multi-band operation with a single antenna. Requires a 4:1 or 6:1 balun.
A half-wave antenna fed at one end through a 49:1 impedance transformer. Excellent for portable operations and works on multiple bands with a tuner. No radials required.
A random length wire antenna (typically 1 to 4 wavelengths long) fed at one end. Requires an antenna tuner and a good ground or counterpoise. Excellent for multi-band operation.
A vertically polarized antenna that's quarter wavelength long. Requires a good ground plane or radials for optimal performance.
Directional beam antenna with one reflector, one driven element, and one or more directors. Provides gain and front-to-back ratio. More elements = more gain but narrower bandwidth.
A quarter-wave vertical with elevated radials. Radials are typically angled downward at 30-45 degrees to achieve 50Ω impedance.
