Enter your wire details on the Setup tab and tap Calculate antenna — the multiband comparison will appear here, calculated for your actual wire and frequency.
Quick-select guide
Balun — balanced ↔ unbalanced.
UnUn — unbalanced ↔ unbalanced.
Choke — suppresses common-mode only, no Z transform.
1:1
Current choke balun
8–12 turns of coax on FT240-43 or FT240-31. Suppresses common-mode current. No impedance transform. Essential at every coax-fed balanced antenna.
ChokeBalun4:1
Guanella current balun
Two bifilar chokes in series/parallel on FT240-43. Transforms 200 Ω → 50 Ω. Best for folded dipoles, delta loops, doublets on ladder line.
Balun4:1
Ruthroff voltage balun
Trifilar wound on FT240-43. Good only on resistive balanced loads. Degrades at high SWR. Prefer Guanella for field use.
Balun9:1
UnUn — random wire
Autotransformer 3T:9T on FT240-43. Transforms ~450 Ω → 50 Ω. Pair with an ATU for multi-band random wires.
UnUn49:1
EFHW UnUn
3 primary / 21 secondary turns on FT240-43 (7:1 turns → 49:1 Z). Transforms ~2450 Ω → 50 Ω. Add 100 pF across primary. Stack two cores for >200 W.
UnUn16:1
UnUn — high-Z loads
Autotransformer tapped at 1/4 of turns on FT240-61. Transforms ~800 Ω → 50 Ω. Useful for off-resonance end-feds presenting 600–1000 Ω.
UnUnW2DU
Bead choke (1:1)
50–100 Fair-Rite #43 or #31 beads slid directly over coax — no winding. Very broadband 1–54 MHz.
Choke