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Antenna Calculator
Starting lengths for common wire antennas, plus coax cut length. Real-world results vary with height and surroundings — trim to resonance with an analyzer.
½λ Dipole (total)——
Dipole — each leg——
¼λ Vertical——
Full-wave Loop——
Coax cut length (electrical ¼λ / ½λ)
RG-58/RG-8 solid PE ≈ 0.66 · foam ≈ 0.80 · RG-6 ≈ 0.82 · LMR-400 ≈ 0.85
¼λ coax——
½λ coax——