{"product_id":"4-1-current-balun","title":"4:1 Current Balun 400W, 1-30MHz HF, SO-239 \u0026 Brass Wire Terminals, For Dipoles \u0026 Long Wire Antennas","description":"\u003cp\u003eA \u003cstrong\u003e4:1 current balun\u003c\/strong\u003e 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.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e4:1 impedance transformation (200Ω balanced to 50Ω unbalanced)\u003c\/li\u003e\n\u003cli\u003eCurrent balun design — suppresses common-mode currents\u003c\/li\u003e\n\u003cli\u003e400W power handling\u003c\/li\u003e\n\u003cli\u003eFrequency range: 1–30 MHz (full HF spectrum)\u003c\/li\u003e\n\u003cli\u003eSO-239 (UHF-Female) coax connection\u003c\/li\u003e\n\u003cli\u003e2 x brass screw terminals for antenna wire connection\u003c\/li\u003e\n\u003cli\u003eIdeal for dipoles, folded dipoles, G5RV \u0026amp; long-wire antennas\u003c\/li\u003e\n\u003cli\u003eReduces RF interference \u0026amp; improves antenna performance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eType: 4:1 current balun\u003c\/li\u003e\n\u003cli\u003eFrequency range: 1–30 MHz\u003c\/li\u003e\n\u003cli\u003eMax power: 400W\u003c\/li\u003e\n\u003cli\u003eImpedance: 50Ω (unbalanced) \/ 200Ω (balanced)\u003c\/li\u003e\n\u003cli\u003eCoax connector: SO-239 (UHF-Female)\u003c\/li\u003e\n\u003cli\u003eAntenna connection: 2 x brass screw terminals\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"KAMSAT","offers":[{"title":"Default Title","offer_id":57203299287384,"sku":null,"price":19.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/8753\/5192\/files\/18-001_1.jpg?v=1777457837","url":"https:\/\/kamsat.co.uk\/products\/4-1-current-balun","provider":"Kamsat","version":"1.0","type":"link"}