Formulas: λ = c/f with c = 299 792 458 m/s.
Dipole L = K·VF·λ/2 with end-effect factor
K = 0.945 + 0.0087·log10(L/d), clamped to 0.93–0.985 — an empirical
logarithmic fit of the classical K-vs-(length/diameter) chart
(K ≈ 0.96 at L/d ≈ 50, 0.97 at 1000, 0.98 at 10 000), solved iteratively
since K depends on L. Monopole = half a dipole over its ground image.
Inverted-V: ×0.96 at 90° / ×0.98 at 120° apex, linear in between (empirical
ham practice). Folded dipole: same length, Z × 4. Quad loop: perimeter =
VF·306.6/fMHz m (≈ 1005/f ft). 5/8 vertical: h = 0.625·λ·0.952·VF.
Ham shorthand 468/fMHz ft shown for comparison (embeds K ≈ 0.95).