Subject: ReMore doubts about "hands free" (Dean)(Fist).
Date: Sat, 04 Nov 2000 044719 -0600
From: Roy Beavers
To: guru
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........Response from EMF-L.......
-------- Original Message --------
Subject: Re:More doubts about "hands free" (Dean)...
Date: Sat, 04 Nov 2000 12:37:53 +1100
From: Stewart Fist
Reply-To: fist@ozemail.com.au
Organization: Independent writer and columnist
To: roy@emfguru.com
References: <3A0209FE.BD4DE438@emfguru.com>
After reading the Which claims, I still remain unconvinced.
Note that the claim is that the hands-free kits "can" or "could"
increase head exposure -- not that they do, or that they do-on-average
-- transmit more.
This reads to me like an organisation with its backs to the wall, not
wanting to admit a mistake.
We all know that if the lead passes right over a R/F hot-spot in the
body of the phone, it 'can' induce high levels in the earphone cables.
But that would depend on how the phone was held, and how the lead fell
in relationship to the hot-spot.
However I'm glad this has arisen and is being debated because it might
make the manufacturers look more closely at shielding parts of the
electronics.
But I'm not convinced that hands-free kits increase (on average) the
dangers, not reduce them. All other tests from all other laboratories
around the world say the opposite.
On a similar note, however, I should point out that early car-mounted
models of GSM mobile phones had a similar problem. In a very early
forum on this subject on Compuserve we were having long discussions on
the likelihood that car-phones would be safer than mobile handsets,
because of the antenna being on the roof, and the user being protected
by the metal (Faraday) shielding.
Then a couple of engineers in the forum, did some measurements and found
that the shielded microphone cable actually radiated much more RF than a
handset (the car phones were higher power) -- so the user actually got
more exposure.
This power was radiating from the metal protective shield of the handset cable.
Generally, it would be possible to design the electronics to avoid these problems.
--
Stewart Fist - writer and columnist
See http://www.australianIT.com.au/opinion/crossroads/
http://www.abc.net.au/http/sfist/ (some archives)
http://www.electric-words.com (main archives)
70 Middle Harbour Road, Lindfield, 2070, N.S.W, Australia
Phone +61 2 9416 7458 Fax +61 2 9416 4582
Archive provided courtesy of WaveGuide, http://www.wave-guide.org
Reprinted with permission of Roy Beavers, http://www.emfguru.com