Far better is to use parallel line, that looks like ordinary TV twin lead, and tune it and the antenna to whatever band you operate. It is lower loss than coax used in multiband operations. A dipole can be shortened to only 60 per cent of its normal length and not give up noticeable efficiency. See Cebik antenna web site: www.cebik.com for discussions on antennas and sizes. 72, Stuart K5KVH