After looking at the range of available equipment from a power perspective, there appeared to be two groups, one in the 600 watt range and the other at or near the 1.5 kw legal limit. Knowing that the latter would give me only slightly more than a 3db difference and considering the cost difference, the choice was easy, to set a power cap of 600 watts.
Once I started building my farm, I began to realized the mechanical advantage of using smaller coax, RG/58, which has a power rating of 700 watts up to 40 meters and acceptable loss. Outside my shack I have a tall pine tree (center) supporting separate 160, 80 and 40 meter dipoles arranged in a star configuration. The hanging RG/58 is thin enough to be almost invisible and the weight is much less than larger coax. Another weight consideration is that 50 small ferrite choke beads fit nicely on RG/58 (from the Wireman). A forth advantage is less bulk as it enters my shack.
I use RG/8 (from Davis RF) for 20 meters and up. The 600Watt HyGain triband was ideal for my Elecraft KPA-500.
Pine tree center support. 3 dipoles.
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vertical on metal car port roof
w/ loading coil in short leg