[TowerTalk] Metal roofs and EMI/RFI

[Jim Hoge]

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Metal shingles are correct and they are made from Galvalume- a sheet steel hot 
dipped in a 55% Aluminum/ 45% Zinc bath. Once cut and stamped into shape, they 
are epoxy coated (at least on the top) and a layer of stone or ceramic is 
embedded into the epoxy. The attachment is made with nails penetrating adjoining 
rows. I had no plans on mounting a vertical on the roof, it's an 8-12 pitch. The 
concern was solely on the possibility of increasing my noise levels. I 
understand it may well effect patterns and takeoff angle of nearby antennas and 
that might work to my advantage. The nearest broadcast antenna is about 9 miles 
away and I am on the side of its directional pattern. The bigger issue is my 
proximity to DFW airport and all of its spectrum pollution, about 3 miles to the 
nearest paved surface. Thankfully I have no airplane noise as I am perpendicular 
to the runways and a hill separates me from it.

tnx for the responses es 73, Jim W5QM