A 4:1 current balun is an essential accessory for HF antenna installations, transforming the impedance from 200Ω (balanced) to 50Ω (unbalanced) while suppressing common-mode currents on the coax outer braid — reducing RF interference, improving antenna pattern symmetry, and protecting your transceiver. This unit covers 1–30 MHz across the full HF spectrum with 400W power handling, making it suitable for most amateur radio and CB base station setups. Connects to your coax via SO-239 (UHF-Female) and to your antenna wire via two brass screw terminals. Ideal for use with centre-fed dipoles, folded dipoles, G5RV antennas, and long-wire antenna systems. Key Features 4:1 impedance transformation (200Ω balanced to 50Ω unbalanced) Current balun design — suppresses common-mode currents 400W power handling Frequency range: 1–30 MHz (full HF spectrum) SO-239 (UHF-Female) coax connection 2 x brass screw terminals for antenna wire connection Ideal for dipoles, folded dipoles, G5RV & long-wire antennas Reduces RF interference & improves antenna performance Technical Specifications Type: 4:1 current balun Frequency range: 1–30 MHz Max power: 400W Impedance: 50Ω (unbalanced) / 200Ω (balanced) Coax connector: SO-239 (UHF-Female) Antenna connection: 2 x brass screw terminals
