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Copyright: 1996 - 2024
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    Kirt Blattenberger,

    BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while typing up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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Poll: Is Cellphone/WLAN Radiation Damaging? - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues - primarily having to spend time purging garbage posts from the board. At some point I might start the RF Cafe Forums again if the phpBB software gets better at filtering spam. Note: The RF Cafe Forums were reconstituted in April 2021!

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Is Cellphone/WLAN Radiation Damaging?
Yes, but I'll take my chances.    19%  [ 3 ]
Yes, and I rarely use either.    13%  [ 2 ]
Yes, and I never use either.    13%  [ 2 ]
No, not enough to worry about.    44%  [ 7 ]
I just know I love that warm, tingling feeling I get from them.    13%  [ 2 ]

Total votes : 16

Kirt Blattenberger
 Post subject: Is Cellphone/WLAN Radiation Damaging?
Posted: Sun Apr 08, 2007 12:00 pm 
 
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Joined: Sun Aug 03, 2003 2:02 pm
Posts: 451
Location: Erie, PA
Greetings:

The topic of SAR levels from cellphones, WLAN systems, etc., have been the subject of as much controverting discussion and debate as that of 60 Hz overhead high voltage lines was back in the 1970s and 1980s. Typical of all these types of issues, "experts" on both sides of the table argue with every ounce (28.3 grams) of credentialed bloviation that can be mustered. If you watch the daily Technical Headlines, you have noted the authoritative reports claiming one week that conclusive testing show no imminent danger from having 2 watts of 900 MHz – 2100 MHz RF energy crawling around your brain of a watt of 2.4 GHz energy blasting into your lap from your notebook wireless transmitter (we will not even address the danger to procreation purported to exist from the heat conducted into those same lap areas). :smt100

What is your opinion of the SAR issue? Do you believe it is a problem, or just a way to get government grant money to do more studies?

_________________
- Kirt Blattenberger :smt024
RF Cafe Progenitor & Webmaster


 
   
 
yendori
 Post subject:
Posted: Mon Apr 09, 2007 3:55 pm 
 
General
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Joined: Thu Sep 25, 2003 1:19 am
Posts: 55
Location: texarcana
I think cell phones have been around long enough where we would be, at least seeing the beginning of any negative issues of their use.


 
   
 
wb9jtk
 Post subject:
Posted: Tue Apr 10, 2007 10:12 am 
 
Captain
User avatar

Joined: Tue Dec 26, 2006 5:39 pm
Posts: 21
Quote:
I think cell phones have been around long enough where we would be, at least seeing the beginning of any negative issues of their use

How many cellphones are there in the world ? 500 million maybe ? So where is all the brain damage ? Apparently it only affects lawyers.

Quote:
2 watts of 900 MHz – 2100 MHz RF


I just looked up my cell phone on the FCC database. IHDT56FY1
Maximum ERP is 29.4 dBm at the antenna connection at 836 MHz.
Maximum ERP is 29.5 at 1850 MHz.
So maximum effective radiated power is about 1 watt. Now even if we put the phone up against our head and assumed that our head did not change the radiation pattern, less than 1/2 watt could go into our head. Can 1/2 watt make a detectable change in temperature of the tissue or fluids ? I honestly do not know. And I have tried to understand all that "SAR" stuff, but still do not. (SAR = "specific absorption rate") What is the "skin depth" of 850 MHz and 1900 MHz? I expect that some of the highly educated readers of RFcafe will be able to tell me.

I ask this, because one of my favorite professors in college, and chairman of my thesis committee was K5AAK, Dr. Jefferson Lindsey III. He told us of working on the antenna for the backpack that astronauts wore on the moon. The RF link from the backpacks to the lunar lander was 297 MHz (as close as I remember). They determined that a LIVE human head absorbed 297 MHz. (They were surprised to discover that this was not the case when testing with cadavers.) It was too late to change the frequency. So off they went to the moon with a cardiod radiation pattern. (The null being the direction the astronaut was facing). From this I infer that 300 MHz would be a risk to humans, not 1900 MHz.

But still.... where are all the people damaged by cellphones. We have 10s of millions of people using them for long periods every day and we have many years of 'exposure'.



RE: Low frequency fields

See the book
Quote:
"Possible Health Effects of Exposure to Residential Electric and Magnetic Fields"
published by the National Research Council (National Academy Press 1997) ISBN 0-309-05447-8 .

There is precisely ONE effect from athermal non-ionizing radiation; it causes broken bones to heal faster.

I am amazed how many people quote some seriously flawed 'research'. The most prevalent quotation of crap is a research project where an idiot subject rats to 35 millwatt per square centimeter of microwave radiation. He pulsed the radiation at 15 Hz. His moronic conclusion is that 15 Hz (low frequency radiation) is harmful. How anyone would quote a guy that thinks 2450 MHz is "low frequency" is beyond me. Also, this power level was enough to actually change the body temperature of the rats. Thus this is not even in the category of 'athermal radiation'.

I am also amazed at how many people think that microwave ovens are dangerous. Well, if you mess up your door 'seal', I would call it dangerous also. But they seem to think that 12 cm radiation causes cancer. Hmmm.. they feel perfectly safe cooking their food in an electric oven. And many people love to 'broil'. Well.. 'broiling' is pretty much cooking with wavelengths of a micron through hundreds of microns. (Note to many people that were educated in the USA, a micron is 1/1000 of a millimeter, it is not in anyway related to that freaky unit of measurement that is called an inch.)
We all see what sunlight does to everything it hits. So much 200 nanometer and shorter radiation .....
Seems to me that cooking with 12cm electromagnetic waves would be a heck of a lot safer than cooking with 1 micron waves.


 
   
 
kpainter
 Post subject:
Posted: Tue Apr 10, 2007 11:43 am 
 
General
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Joined: Wed Aug 20, 2003 11:47 am
Posts: 84
Location: Santa Barbara, CA
yendori wrote:
I think cell phones have been around long enough where we would be, at least seeing the beginning of any negative issues of their use.


I think you will find that the real harm is GLOBAL WARMING!!!


 
   
 
yendori
 Post subject:
Posted: Thu Apr 12, 2007 2:47 pm 
 
General
User avatar

Joined: Thu Sep 25, 2003 1:19 am
Posts: 55
Location: texarcana
Perhaps cell phones damage the conservetive thinking part of the brain?

That would explain why the threat of global warming, and not the threat of global terrorism, is the big story.


 
   
 
kpainter
 Post subject:
Posted: Fri Apr 27, 2007 12:10 pm 
 
General
User avatar

Joined: Wed Aug 20, 2003 11:47 am
Posts: 84
Location: Santa Barbara, CA
This gal thinks cell phones make her sick. I think she is just plain old fashioned nuts:
http://www.dailymail.co.uk/pages/live/femail/article.html?in_article_id=450995&in_page_id=1879






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