AntennaKNoBs

New in v0.27.0

Nine Cebik designs, and bring your own NEC decks. The catalog grows by nine antennas modelled from L. B. Cebik (W4RNL)‘s articles — the Extended Double Zepp and expanded lazy-H, the OWA Yagi and its 40 m counterpart (a phased-driver wire Yagi holding the whole band under SWR 1.5 through one half-twisted line), two more self-contained verticals (the “magnetic slot” rectangle and right-angle delta), a satellite Moxon turnstile fed through a real quadrature harness, the Tri-Moxon switched vertical array (three fixed beams, a coax switch instead of a rotator), and a terminated end-fed long-wire — the catalog’s first design whose wires connect to ground. And read_nec now imports a NEC2 card deck — the format xnec2c, 4nec2, EZNEC, and decades of handbooks speak — as a viewable, solvable design, honouring the deck’s geometry transforms and feeds and matching an independent nec2c solve to 0.011 Ω. All release notes →

The whole pitch, in one line

antennaknobs describes an antenna as Python code — a small parametric builder, its geometry computed from named knobs — then lets you explore it two ways: drive it from a script (sweep, optimize, compare, export a NEC deck), or open it in a browser and turn the knobs live, watching the radiation pattern, SWR, and impedance respond as you drag. Most antenna tools are a static formula calculator or a desktop app you have to install; this is neither.

Antennas as Python code

Describe an antenna once as a small parametric builder — geometry computed from named knobs — then sweep, optimize, compare, or open it in the browser. Most tools make you hand-place every coordinate.

Multi-basis MoM

Sinusoidal and B-spline bases in one engine, cross-validating each other — basis quality that otherwise costs four figures in commercial tools.

Fast on big arrays

H-matrix / ACA acceleration with GMRES, where every free NEC tool is dense O(N²). Demonstrated O(N log N) on a 2142-segment Yagi.

Cross-checked physics

A NEC-2 reference engine runs alongside the in-house solver, so you get a built-in accuracy check most tools lack.

No platform lock-in

A web UI by default — works anywhere a browser does, while the competition is Windows/Linux/macOS desktop-only or a GUI-less library.

Start here

What is antennaknobs? The tool, who it's for, and how the pieces fit.

Quickstart pip install, then a resonant dipole in ten lines of Python.

Many ways to express geometry The same delta loop, one knob-set, built four different ways — pick the one that fits how you think.

The solver & accuracy Bases, H-matrix acceleration, and how it's validated.