Dipole Antenna Configuration Calculator

Methodology & Design Notes

The engineering behind the length formula: total wire length is calculated as 492 × K / f(MHz), the more fundamental form of the classic "468/f" rule — 468 is just that same formula with K fixed at 0.95, the standard end-effect factor for AWG 12–14 wire. Making K adjustable lets you start a bit long (K closer to 1.00) and trim down to resonance, or dial in a different factor for heavier gauge wire or tubing. For Inverted-V and V-Dipole, an additional apex-angle shortening factor is applied — legs droop from a flat 180°, and the tighter that angle gets, the shorter the resonant length becomes (roughly 5% shorter at a 90° apex vs. a flat-top). This is a widely-cited rule of thumb, not a precise NEC model, so treat the output as a solid starting point to cut and trim, not a guarantee of first-try resonance.

Diagrams:

• Each of the five mounting configurations gets its own to-scale-ish schematic with dynamically updating leg-length labels, so you can see exactly how the numbers map onto real wire runs.
• Every configuration is fed at its true electrical center, same as any real dipole — including the Sloper, where the feedpoint sits partway down the slope (not tied off at the high end), splitting it into two equal legs just like the other four.