[BC] uplink ERP - RF hazard?

[Jerry Mathis]

I doubt seriously you'd even get the sunburn. We're talking **1** watt here.
That's all there is. What you have to remember is that the so-called "gain"
of the dish is simply its ability to FOCUS that 1 watt in a single
direction. The gain figure comes from calculating what the power radiated
from an isotropic (meaning a theoretical single point of radiation) antenna,
would have to be to equal the signal strength in the strongest lobe from the
dish antenna. Using your numbers, the dish can focus your 1 watt of power
into a signal powerful enough, AT ITS  STRONGEST POINT, to equal a
non-directional antenna putting out 20,000 watts. Keep in mind that the
signal from a 20,000 watt non-directional antenna would be bathing your
whole body in radiation--not just the small point from the beam that the
dish puts out.

So-called power gain is not magical; it is simply the ability of the antenna
to focus the energy fed into it. The law of conservation of energy is still
in effect.

Jerry Mathis


On 1/12/08, Cowboy <curt at spam-o-matic.net> wrote:
>
> On Saturday 12 January 2008 10:29 pm, John Lyles wrote:
>
> >  Is this level at 29.75 a hazard? I can check the IEEE/ANSI standard
> myself,
> >  but just wanted a general collective opinion. Since this is a home
> >  environment, I would have to set my own safety standards such as
> turning
> >  off the modem when working on the roof (it is flat and the dish is
> being
> >  placed there Thursday). I have VHF, television, amateur, UHF, yagis,
> you
> >  name it, already up there.
>
> 2.9 would be a greater hazard ! ( more penetration depth )
>
> This is NON-ionizing radiation. To those of us that know the difference,
> the worst you could likely get, is a mild sunburn.
> Of course, blindness and sterility just like any radar transmitting array
> if you stay there long enough directly in the boresight.
>
> I'd walk across it without a second thought, but I wouldn't stand there
> three
> feet in front of it for hours on end.
>
> --
> Cowboy
>
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-- 
Jerry Mathis