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Old August 11th 08, 08:18 PM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Jun 2006
Posts: 147
Default Blackberry power level 4.9GHz

In article ,
John Smith wrote:

You wrote:

...
Now all you need to prove, is that the RF Power Density of a 300
Milliwatt Cellphone, operating one one of 4 Bands in the 800-900
...


Let's say just those figures are correct ...

My Motorola Razar V3 phone is approx. 6mm thick (when opened), and where
the antenna is buried in the phone. This means the antenna can be no
more than 6mm from my head if the phone lies against my head. Now, we
assume the phone is emitting 300mw. This would be equivalent to 1.2w of
power emanating from that same antenna at a distance of 12mm from my
head. And, the latter would be equivalent to 4.8w emanating from the
same antenna at a distance of 24mm from my head. And, the last would be
equivalent to 19.2w emanating from the same antenna at a distance of
48mm from my head ... your higher figure, of two watts, is simply
frightening ...

The lunacy is exposed ... correct any error you see in the above ...

Regards,
JS


Sonny, you seem to be using the Inverse, of the Inverse Square Law
here.... the Farther the source is from the receiver the LESS power
reaches the receiver, not MORE. It goes Down, by the SQUARE of the
distance, not up. You also don't get ALL of the 300 Milliwatts
going into your head as the antenna is semi Omni-directional and
only about 120 degrees of the 360 degree transmitted signal will
intersect with your head, and another maybe 10 degrees with you hand.
Better go back and do the Sums, AGAIN, or leave it to folks that
passed Jr. High School Math, and High School Physics.