Here are some but not all tv antenna mounts,
http://www.eham.net/libraries/download/430/Photo_A.jpg ,
http://www.sadoun.com/Sat/Products/Perfect/PVEM1.gif ,
http://www.rohnnet.com/files/Tripod_Roof_Mounts.jpg . Notice the wide spacing of the straps of the chimney mount , this makes the mast and antenna stable. Notice the wide spacing between the two brackets of the eave mount , this makes the mast and the antenna stable. Notice the tripod mount , this will make the mast and antenna stable.