[ RadSafe ] WHO: Cell phone use and physics

Geo>K0FF GEOelectronics at netscape.com
Thu Jun 2 15:33:28 CDT 2011

"Any(R.F.) energy quantity smaller than the quantum required to 
break-up a bio-molecule has absolutely no effect on that molecule, or 
the probability that something happens to that molecule is practically 
Enrico Sartori, PhD"

Enrico, address Microwave Ovens please?

Their present frequency has little to do with actual physics, rather to
FCC licensing issues.
Speaking of the FCC, in recent years they have imposed RF exposure limitations, 
even to amateur radio operators.

Anyone working around microwave transmitters (I have) know that there are measurable effects, and 

In 1963 the FCC allocated the frequency band 2500-2686 MHz for educational purposes. 
In the 60's I was involved in surveying for and installing the first such system in St. Louis Mo, on channel H1, 2650-2656. 
We used a power level of 10 Watts, but up to 100 Watts was authorized.
About this same time, Police Speed Radars were removed from 2400 Mhz up to 10,000 MHz.

 In 1972, the FCC authorized commercial use of the sub band 2150-2162 MHz. Again I installed 
and maintained the first of the MDS Multipoint Distribution Systems in St. Louis MO. We started with 
10 W but as technology advanced, escalated to 100W. In 1983 they opened some channels up to 
multiplexing ( more than one TV channel per RF Channel). This was the beginning of what is now 
Cable TV and Satellite TV, but we used microwaves to distribute the TV, Audio and Data signals to the paid users. 

Mind you these services were often point-to-point, allowing the use of directional gain antennas. An 
antenna with 20 dBi gain will give an effective isotropic (EIRP) radiated power of 1000 Watts from a 100 Watt transmitter.

There were no warnings, safety zones, lockouts or any other safety measures applied to these antennas. 
As a matter of fact, because of feedline losses, such antennas were NOT mounted high on a radio tower 
far from the generator, but on top of tall buildings, just feet from the generator.The same rooftop occupied 
by humans for a variety of activities. As I mentioned in a previous post, it was my duty on many occasions to 
stands within a few feet of one of these antennas. 

Many services used and still use this style of microwave linking plus many more modern sophisticated schemes.


One can hardly get away from being exposed to microwave fields, even hospitals use a spread-spectrum 
microwave system to feed info from 
medical monitors etc. back top the nurses station.

Got a WIFI computer? Guess what the RF link is 2400 and/or 5000 Mhz.

Cell phones can use a number of microwave frequency bands,  850-MHz, 900-MHz, 1800-MHz or 
1900-MHz , with more on the horizon.

Modern cordless phones for your home landline:
a.. 900 MHz (902-928 MHz) (allocated in 1994)
a.. 1.9 GHz (1880-1900 MHz) (used for DECT communications outside the U.S.)
a.. 1.9 GHz (1920-1930 MHz) (developed in 1993 and allocated U.S. in October 2005)
a.. 2.4 GHz (allocated in 1998)
a.. 5.8 GHz (allocated in 2003 due to crowding on the 2.4 GHz band).
Power of the handheld cellphone is limited to 1 little less than 1/3 Watt, but there is no TIME limit on their use. 

WHO calls "heavy use": (reported average: 30 minutes per day over a 10-year period). Haha. Tell that to my grandkids.

Now let's examine the Microwave Oven for a moment. The first one was installed, ironically on the 
nuclear powered passenger ship Savannah, where it remains today.

Modern Microwave Ovens operate at a frequency of 2450 Mhz. Sound familiar by now? Power is 
from several hundred Watts to maybe 700 Watts today.  In any case much less than the free field RF 
density in from of a directional antenna. There is nothing special about the 2450 MHz frequency used, 
it is a spectrum allocation issue. Frequencies as low as 433 MHz
have been used to heat polarized molecules on a large scale.

I don't claim to be a doctor or anything else. I was one the front lines of the communications revolution, 
over a very long period of time. The industry buzz back when was ?take care of the eyes". I wore thick glasses so 
I thought I was fine. Later I learned from experimenting that glass lenses affect the higher microwave frequencies, 
actually focusing them at 10,000 MHz.

Make your own conclusions, I make no judgments, all I do is present facts of physics.


George Dowell

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