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RE: 2.4 gHzCordless Phones



Cute Joe,
The frequency choices were because of water absorption and not the
wavelength of a hotdog. (yes I know you're joking) Water has a couple of
pretty good absorption lines at 900mhz and 2.5ghz.  There is also one at
around 150ghz that also coincides with oxygen.  (That's why the "dx" record
at 150ghz is only just over 1km.)  Most fats are heated better by 2.5ghz
than by the old 900mhz ovens.

I have heard some speculate that the reason you have to punch holes in the
hot dogs is to allow the waves to escape.  It seems that the shape and
diamater of the wiener acts as a waveguide trapping the RF until it reaches
a critical level causing the hot dog to explode!  This was never a problem
with 900mhz ovens because the waves were to long to be trapped inside the
wieners.

[soapbox=on]
As far as cordless phones or cell phones causing cancer....BUNK!
RF energy, as most of you know, does only one thing...it heats the water in
the tissue.  It does not break molecular bonds as some on the tabloid
television shows have stated.  The amount of heating by cell phones and
cordless phones can't even be measured due to the fact that the blood flow
through the tissue dissapates the heat faster than it builds up.  It, as
some have also stated, does not have the cumulative effect of ionizing
radiation such as x-rays.

73/soapbox off

Kevin, WB5RUE

> -----Original Message-----
> From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
> Behalf Of Gary "Joe" Mayfield
> Sent: Saturday, January 20, 2001 2:35 PM
> To: amsat-bb@AMSAT.Org; Edward R. Cole
> Subject: Re: [amsat-bb] 2.4 gHzCordless Phones
>
>
> Honest to God, my sources inform me the original microwave
> tests were on
> cooking a hot dog.  2.4GHz won out because it is about the resonant
> frequency of a hot dog (made it cook faster).
>
> 73,
> Joe
> ----- Original Message -----
> From: "Edward R. Cole" <al7eb@ptialaska.net>
> To: <amsat-bb@AMSAT.Org>
> Sent: Saturday, January 20, 2001 1:53 AM
> Subject: Re: [amsat-bb] 2.4 gHzCordless Phones
>
>
> > >From: "Deon Erwin" <zr1dq@qsl.net>
> > >Talking about 2.4 GHz phones.  People are going crazy
> about 900 and 1800
> MHz
> > >mobile phones and cancer, but they are quite happily using 2.4 GHz
> cordless
> > >phones.
> >
> > It is a bit crazy.  BTW early microwave ovens were built
> for ~900 MHz but
> > moved to 2.45 GHz because that frequency is more efficient
> for heating of
> > organic tissue [may have been an freq. allocation thing as
> well].  Anyone
> > notice the cable "ads" for a patch you put on your head
> that screens out
> > all that nasty cordless phone RF...unbelievable!  Now you can stop
> > smoking...for real.
> >
> > I guess if you use the 2.4G phone enough you might have sufficient
> exposure
> > to be concerned...but the phone bill would kill you faster!  I been
> > thinking of an experiment to see how long it would take to
> bake a potato
> > with my 2.4G spread spectrum phone.  Anyone having trouble with
> > telemarketers calling their oven? OK OK getting serious:
> >
> > My understanding is that the 2.4G cordless is radiating
> only when off
> hook.
> >  When I get a Drake set up I'll be interested to see if there is
> > interference.  In my case the solution is simple...pull the
> plug on the
> phone!
> >
> > Years ago we [NASA] experimented with oven Magnetrons and I
> seem to recall
> > that the power supplies were using avalanche diodes with little dc
> > filtering.  The voltage was around 3.5 kV on the anode.  If
> you switch a
> > high voltage like that at say half an amp there will be a
> fair amount RFI.
> > The "maggys" are putting out broad-band noise due to this.
> >
> > Ed
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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>

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