feat(math): frequency-aware feedpoint R (height in λ) + trap guidance docs#130
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nec_calibrated_dipole_r now interpolates the NEC-calibrated dipole feedpoint resistance on height-in-wavelengths (h/λ = height·f/c) instead of raw metres, so the estimate is frequency-aware. The 7/10/12 m @ 7.1 MHz corpus anchors are re-expressed as h/λ (0.166/0.237/0.284 λ) plus a free-space anchor at 0.5 λ: the 40 m calibration reproduces exactly (corpus tests unchanged), while a 10 m mast reads ~52.8 Ω on 40 m, ~60.8 Ω on 20 m, ~62.9 Ω on 10 m. A representative mean-band frequency is threaded through the advise/EFHW callers. Also documents the trap-dipole per-band-pair guidance model (docs/math.md §11) and its constants (inner leg 71.58/f_u, total leg 68.58/f_l, trap L·C = 25330/f²), and refreshes §9 to note the frequency-aware R. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Backlog T3 + T4 (modeling accuracy + documentation).
T3 — frequency-aware feedpoint resistance.
nec_calibrated_dipole_rinterpolated the NEC-calibrated dipole feedpoint R on raw height in metres, so every band got the 40 m answer. Radiation resistance actually tracks height in wavelengths, so it now interpolates onh/λ = height·f/c:A representative mean-band frequency is threaded through the advise / EFHW callers. Still a coarse first-order model pending multi-frequency NEC data (GAP-011).
T4 — trap-dipole guidance documented. Annotated the guidance constants and added
docs/math.md §11(inner leg71.58/f_u, total leg68.58/f_l— ~4% shorter due to trap loading, trapL·C = 25330/f_u²fromf = 1/(2π√(LC))). Refreshed §9 limits.Test plan: new
nec_calibrated_r_is_frequency_aware_and_preserves_40m_calibration;cargo testall pass, clippy + fmt clean.🤖 Generated with Claude Code
https://claude.ai/code/session_01Jf8uBU8AYxkrG8fa8yo6tC