The favorite brands vary slightly depending on what side of the country your on. For the west coast some of the favorite mountaintop repeater antennas are made by DB Products, Cellwave (Stationmaster, used to be Phelps Dodge), Telewave, some Antenna Specialists, Bogner (for 800-900MHz), Kreco for some specialized stuffy and a few brands I forget.
After big ice and snowstorms on mountaintops the Antenna Specialists fiberglass types seem to break first, then the older Stationmasters but the all aluminum exposed dipole arrays seem to last. Tha hams that put Diamond, Comet, Hustler, Cushcraft and other fiberglass ham antennas on 5000+ ft mountaintops usually learn the hard way after the first big storm.
prcguy