The 1:9 balun consists of 3 wires tide together with 7 windings on an Amidon T200-2 iron core. This balun can handle 200-300Watts. If we use not more than 100W on HF we also can use a T130-2 core. Its weight is a lot less, what is handy if the balun hangs in the feed point of the antenna. I tried both baluns and noticed no difference at all.