We use 10 of our FB-56-43 beads on RG-59 for 160 meters. The total bead impedance on 160 meters is 300 ohms, twice that on 80 meters. -- Commercial: Palomar has kits for this that include beads and shrink tubing to hold them in place. See www.Palomar-Engineers.com -- Jack, K6NY, Palomar Engineers