The Galaxie "20" is thirty inches longer than the "17" and has therefore an outrigger frame to avoid undue whip. With 17.8 dB gain it is in the fringe class and can produce very creditable results. Windloading is just beyond the capability of a lightweight rotator, unless an alignment bearing is used. A simple twin mast is advisable should the mast exceed six feet above the final fixing bracket. Should the requirement be for multiple transmitter reception,  an Orion "10" or "11" could be more economical, allowing the use of a lightweight rotator. The "11" has slightly more gain but a much sharper acceptance angle giving more selectivity and better rejection of closely aligned stations. Front to Back ratio is very close,  and on the "infilled" version of the "11", it is in fact higher for slightly less windload.