CM ============================================================
CM  adcock_hf_40m.nec — TM-ADF-NEC-001 Rev A
CM  Adcock Array for Watson-Watt HF RDF, 40-meter band
CM  Four λ/4 vertical monopoles in N/S/E/W configuration
CM  λ/4 element spacing = 10.5m at 7.15 MHz
CM  Each element: 10.15m vertical wire over ground
CM  Fed at base; combined differentially in Watson-Watt scheme
CM
CM  Geometry:
CM    Element spacing: 10.5m (λ/4 at 7.15 MHz)
CM    N element at (0, +5.25, 0)–(0, +5.25, 10.15)
CM    S element at (0, -5.25, 0)–(0, -5.25, 10.15)
CM    E element at (+5.25, 0, 0)–(+5.25, 0, 10.15)
CM    W element at (-5.25, 0, 0)–(-5.25, 0, 10.15)
CM    SENSE at (0, 0, 0)–(0, 0, 5.0) — short vertical
CM
CM  This model: 5-element array, each element fed separately
CM  For RDF analysis: compare patterns of N-S sum vs. E-W sum
CM  Reference: Watson (1928), Keen (1947), Gething (1991)
CM  Analyze: impedance, radiation pattern, mutual coupling
CM ============================================================
CE
CM --- N element: tag 1 ---
GW 1 20 0.0 5.25 0.0 0.0 5.25 10.15 0.001
CM --- S element: tag 2 ---
GW 2 20 0.0 -5.25 0.0 0.0 -5.25 10.15 0.001
CM --- E element: tag 3 ---
GW 3 20 5.25 0.0 0.0 5.25 0.0 10.15 0.001
CM --- W element: tag 4 ---
GW 4 20 -5.25 0.0 0.0 -5.25 0.0 10.15 0.001
CM --- SENSE element (short vertical at center): tag 5 ---
GW 5 10 0.0 0.0 0.0 0.0 0.0 5.0 0.001
CM
CM End geometry, real ground (Sommerfeld-Norton)
GE 1
CM
CM Ground parameters: average ground (σ=0.005 S/m, ε=13)
GN 2 0 0 0 13.0 0.005
CM
CM Frequency sweep: 7.0 to 7.3 MHz, 7 steps
FR 0 7 0 0 7.0 0.05
CM
CM Excitation: source on N element (tag 1, segment 1, base)
EX 0 1 1 0 1.0 0.0
CM
CM Radiation pattern: elevation cut, azimuth=0, 0–90° elevation, 2° step
RP 0 46 1 1000 0.0 0.0 2.0 0.0
CM
CM Also run with source on E element (tag 3) for E-W pattern
CM (Comment out above EX card and uncomment below):
CM EX 0 3 1 0 1.0 0.0
CM
CM Near-field not computed (PQ not needed for RDF analysis)
EN