Cell Phones Possibly Carcinogenic?

[Bill Cravener]

I just have never been able to adjust to carrying around a cell phone. I find them so annoying and have given it a try several times. But that's just me. I've always felt that all the young people I see who spend hours with one of them things glued to their ear can't be good. I have some understanding of how a cell phone works and I understand that they only use low-power transmitting in the GHz ranges at the phone side and that they are then picked up by local more powerful receiver towers. I'm seeing them pop up everywhere around my area of the planet these days.

http://www.reuters.com/article/2011/06/01/uk-cancer-cellphones-idUSLNE74U06620110601

http://www.freep.com/article/20110601/NEWS07/106010328/Cell-phone-cancer-worry-again

A thought just came to me, I wonder how much money is or will be behind keeping this subject low keyed. I mean if cell phones are shown to contribute to the cause of brain tumors what would that do to the cell phone industry? Or is it like an addiction where you've got to have it even if it kills you?

[dedndave]

i developed a cell-phone antenna that greatly reduces the amount of radiation "absorbed" by the skull
cell-phone manufacturers aren't interested in your health
when the government makes it manditory, maybe i'll make a little casholla   :P

[clive]

A thought just came to me, I wonder how much money is or will be behind keeping this subject low keyed. I mean if cell phones are shown to contribute to the cause of brain tumors what would that do to the cell phone industry? Or is it like an addiction where you've got to have it even if it kills you?

Like tap water for instance, which is likely the primary route for ingesting carcinogens in every day life. While I can see putting a 1W transmitter next to your head is a bad plan, I'd be more worried about the field strengths from TV/Radio transmitters, and HV power transmission lines.

For that matter, you are more likely to get killed by the moron driving and talking on the phone crashing into you, than either of you getting cancer from it or the cell tower.

[dedndave]

lol - yah - the blonde doing her makeup and texting while driving comes to mind
she is more likely to kill someone

as for EMI field strengths, the field is proportional to level, but inversely proportional to the square of the distance
higher frequency EMI is typically more harmful than lower

with those rules in mind, cell-phone radiation is relatively dangerous
it's not just the 600 mW (or whatever level), it's the fact that it's higher-frequency EMI held right next to your head

i'm not sure that cancer is the major concern, though
it fries brain (and possibly eye) cells like cooking hamburger in a microwave oven
this could cause problems that are not necessarily related to cancer
the problem we may see is that they do a study against cancer, and fail to see the true nature of the harm that is done

forgetting how to write assembler could be the second thing to go
i can't seem to remember what the first thing was   :bg

[FORTRANS]

i developed a cell-phone antenna [snip]

Hi,

   Do you know of a handy-dandy guide to making an indoor
FM antenna?  At least better than the simple wire the radio
was sold with.

Regards,

Steve N.

[sinsi]

A thought just came to me, I wonder how much money is or will be behind keeping this subject low keyed. I mean if cell phones are shown to contribute to the cause of brain tumors what would that do to the cell phone industry? Or is it like an addiction where you've got to have it even if it kills you?

Sounds a bit like the tobacco industry...

[bozo]

i've always wondered how harmful Wireless LAN signals were and prefer to use ethernet connections now just to be on the safe side, it runs faster anyway.

[dedndave]

wireless LAN is relatively low power - no worries, there

Steve...
a simple dipole antenna usually works quite well
get it as high as you can - outdoors is nice, but not necessary
try to place it somewhere away from other metal objects

if your tuner/reciever has a 75 ohm input, use a simple dipole antenna
dipoles can be made from any type of wire and the feed line is 75 ohm coax
if it is 300 ohm, a folded dipole is good - both the antenna and feed line are made from 300 ohm "twin-lead"
both antennas are fed at the center
you can also make a 300 ohm half-wave dipole with regular wire by off-center feeding it at 2/3 the length (called a windom)
the length (feet) of the antenna is 468/F(MHz) (this is an adjustment on the half-wave length formula)
the FM band is 88 to 108 MHz
it is better to have an antenna that is too long than one is too short
so, use something like 95 MHz for all-around use
it is good practice to make the transmission line an odd multiple of quarter-wave lengths
the physical length vs electrical length is a ratio called the "velocity factor"
for 300 ohm twin-lead, the velocity factor is roughly .98, and may vary only slightly from one type of line to another
for coax, the velocity factor may be anything from .6 to .8 - usually around .66
you can google the specific coax used and find the velocity factor
so - a quarter wave-length transmission line is...
L(feet) = (246 x velocity factor)/F(MHz)
you want an odd multiple of that length



FM broadcast transmitters are vertically polarized
it may be best to orient the recieving antenna the same way
although, by the time the signal reaches you, it is likely to be randomly polarized   :P
if you orient a dipole vertically, it will be omnidirectional
if you orient it horizontally (as shown in the pic), it will be more-or-less bi-directional
signals off the broad side will be stronger and weaker off the ends
sometimes, the directionality is used to "null-out" unwanted interferance

[FORTRANS]

Hi Dave,

   Thank you.  Now to look about the house and see what
coax cable is lying around.  That, hopefully, will be easier.

Cheers,

Steve N.

[drizz]

Isn't this old news? Also if you must carry it, don't put it in your trouser pocket   :wink

Anyway, I would rather you discuss exploitation of Africa an its people for resources used in the production of cell phones.

But then again why bother, there will still be people camping outside the stores for their latest and greatest.

[bozo]

Anyway, I would rather you discuss exploitation of Africa an its people for resources used in the production of cell phones.

But then again why bother, there will still be people camping outside the stores for their latest and greatest.

I did watch a documentary called 'The Chinese are coming' which goes into some of that subject but overall it's a controversial topic which i've found ends in disagreement, that's not to say we would disagree BTW ;)

You can see documentary in 4 parts below.

http://www.youtube.com/watch?v=qRxuukQ2RdY

http://www.youtube.com/watch?v=PnwWXvd99to

http://www.youtube.com/watch?v=YUYcwX6u8iU

http://www.youtube.com/watch?v=WxI-fPhPgZw

[FORTRANS]

Hi Dave,

   Okay, I built a dipole antenna.  And it does work better
than the piece of wire that came with the radio.  Thank you
for the guidance.  Went from one good and one intermittent
two what now seems like two good ones.  The third wanted
is still AWOL.  Now if I can just avoid tripping over the coax.

   Trick question, how do you get solder to stick to the shield
wires?

Regards,

Steve N.

[dedndave]

if it's aluminum, you don't   :bg
if you are using the commercial RG-6 stuff, you really can't solder to it
you need to come up with some kind of clamp or something
you can use the crimp or thread-type F-connectors
or - strip it back a ways - lay your wire on there
wrap it tightly with some copper wire and solder it to keep it together

a better way to go is to get some RG-59 coax (also 75 ohm)
it has a copper braid shield - easy to solder
the problem with that is - it is smaller in diameter than RG-6
if you want F-connectors to fit, you have to special-order them (pasternack)
you can put BNC or PL-259's on it and get an adapter - maybe more trouble than it's worth

low-price cables, connectors, adapters...
http://www.pasternack.com/

[FORTRANS]

Hi,

   Yes, it says RG-6 on the cable.  And after way too much
effort (stubborn?) I clamped it and got some solder on the
clamp.  Didn't know about RG-59 using copper.

Cheers,

Steve

[dedndave]

well - RG-59 isn't very common anymore
ham radio operators use it for dipoles, mostly
not like you need 500 feet of it thought, either

you are more likely to see RG-58, which is 50 ohm
it may work ok for what you are doing
it is far more common because most CB antennas and many ham antennas are 50 ohm
it looks just like RG-59, except smaller diameter

remember - 300 ohm twin-lead will also work if you look at the dipoles above
you can get a 4:1 balun to convert 300 ohm to 75 ohm at radio shack
i don't know what's available at your location