Originally Posted by Hants
Hmmmmm. I thought that, at 50W, I basically didn't need to worry about RF exposure. At 6ft, the bumpers would be the only option?
The FCC recommends that on VHF you evaluate your exposure at 50W and higher. There is no perfect good/no good power, it depends on the antenna gain, transmitter power, distance and what's between you and the radiating antenna. An omnidiectional 1/4 wavelength antenna has a closer safe distance than a 1/2 wavelength, for example. A highly directional antenna like a yagi or a horn will have a high exposure zone and a much reduced off axis zone where exposure is much lower. Anyway, the roof is very good since you have the sheet metal between you and the antenna. You only need to give it some thought if there isn't a shield between you and the antenna. The bumper is generally OK exposure wise from the cab at 50W, but is something of a compromise depending on the antenna design.