9:1 Balun unun - Top band 1.8MHz duel cores View Gallery Product Details 9:1 Balun unun - Top band 1.8MHz duel cores 91Balun1.8MHZ Product Condition: New Units in Stock: 9 £27.00 inc. tax Product Description Specially wound for the top band.Most uluns dont have enough windings on the core to be efficient!! This ulun has optimum windings covers 1.8 to 3.8 mhz. Duel powdered iron cores allowing 600 watts of power. Brass terminals allowing optimum power to the so239 socket. Marine grade stainless steel bolts throughout. IP rated waterproof housing we even upgrade the screws to stainless steel here too.