01-21-09 11:11 PM
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  1. jprint714's Avatar
    Ive notice that the Blackberrys seem to have rather high Specific Absorption Rate (or SAR) for many of their phones. Im considering getting a 8220 flip and was wondering if there were any ideas about how to shield or reduce the radiation. For example, does anyone know about the airtube headsets or the SAR shields or any else at all? Thanks very much!
    01-11-09 05:04 AM
  2. apoc90's Avatar
    Jawbone bluetooth.


    Seriously, it's the best accessory I've ever had. I use it every day. It works better than anything you can imagine.
    01-11-09 05:16 AM
  3. Pete6's Avatar
    If this is an issue for you and you are one of the approximately 1 in 1000 people who are mildly electro-sensitive then I would choose another phone with a lower SAR number.

    It is extremely difficult to shield electromagnetic radiation AND keep the phone connected to the network.

    Acoustic coupling headsets help as you rightly say. However the phone is still happily radiating away in your pocket or purse. Even bluetooth headsets radiate somewhat even though it is a tiny amount.

    Very little can be done to reduce this.

    Te best way to reduce this radiation is to use the phone less and stay away from towers completely. Remember the inverse square law of doubling the distance to quarter the power.
    01-11-09 05:18 AM
  4. tmv112's Avatar
    Ive notice that the Blackberrys seem to have rather high Specific Absorption Rate (or SAR) for many of their phones. Im considering getting a 8220 flip and was wondering if there were any ideas about how to shield or reduce the radiation. For example, does anyone know about the airtube headsets or the SAR shields or any else at all? Thanks very much!
    you could always put aluminum foil on your ears while talking---it may absorb some of the radio frequency transmissions--
    01-11-09 08:37 AM
  5. Mamaluka's Avatar
    I put my phone in an empty can of Kram Mars appetizer. It's the perfect size for a 8330.
    Serve with pride
    Eat and enjoy

    Posted from my CrackBerry at wapforums.crackberry.com
    01-11-09 08:49 AM
  6. jprint714's Avatar
    Thanks very much for the bluetooth suggestion. Others have made similar recommendations.

    I'm not mildly electro-sensitive, but want to be mindful of mitigating a phone's radiation, whenever possible. Just check out RIM's SAR levels on CNET or elsewhere -- they're comparatively higher than many other cell phones. Again, shielding such radiation might not be possible but reducing it seems tenable. Any other thoughts? Thanks again...
    01-12-09 02:38 AM
  7. Pete6's Avatar
    1). If you are really worried about this then it would perhaps be better to choose a different phone.

    2). Using the phone less keeps exposure to a minimum.

    3). SWitching it off when not in use clearly elimintates exposure whilst off.

    4). staying clear of the phone whilst it is switching on will help too.

    5). Using the phone in a high signal area whilst stationary (not in a moving vehicle) helps.

    6). Avoid use in heavily built up areas so as to reduce multi-pathing.

    7). Whilst not in use but switched on, increased distance between you and the phone (inverse square law) will further reduce exposure.
    01-12-09 03:14 AM
  8. jprint714's Avatar
    Thanks. Anyone else have other ideas on some of the devices out there that mitigate EMF/radiation? Thank you...
    01-13-09 01:51 PM
  9. Branta's Avatar
    Pete6 is correct. The only way to reduce exposure is to apply the inverse square law. Create more distance between you and the source. You can do this by using bluetooth, or speakerphone.

    Gadgets don't work unless they get hot in use or have a grounding path, the RF energy they might absorb has to go somewhere. This is basic Physics 101, you can't destroy energy, only convert it to a different form.
    01-13-09 03:38 PM
  10. xxxxpradaxxxx's Avatar
    Isn't it just as bad as useing a Bluetooth?

    I see people wearing them all day, as if it were jewelry.

    That has to be emitting some form of energy.

    The Phone is Receiving a Signal, then Sending that Signal To the Bluetooth...

    Right?

    I'm not to sure how Bluetooth works, I am very interested in finding out!

    Also, wouldn't WiFi also be similar?

    Walking through a Constant "Net" of Signals?

    Also, Haven't VZW BlackBerry's been shown to give off more SAR???
    01-13-09 04:16 PM
  11. xxxxpradaxxxx's Avatar
    LOL

    This Thread Makes Me Crave a Nice Thick Lead Box.

    If it could shield Superman from Kryptonite Radiation-

    It Shouldn't have any issues with Cellular Signals.
    01-13-09 04:27 PM
  12. Branta's Avatar
    Bluetooth is very low power level. Maximum working range for Class 1 is 100m, and for Class2 about 10m. I don't have the permitted RF power outputs to hand, but I expect much less than 1 milliWatt compared with up to 2 Watts for the phone on max power.
    01-13-09 05:31 PM
  13. senectus's Avatar
    Many years ago when bluetooth first came out I forked out nearly $500 for the first unit to hit the shelves.

    Iwas an ericsson unit that had a warning in the booklet that said "Extended use of bluetooth microphone may result in the drying out of the eyeball"


    I'm not convinced that Mobile Phones are a big risk, but neither do I think that having a bluetooth unit strapped to your head all day every day is a great idea either :-P
    01-13-09 05:49 PM
  14. ShortStop51001's Avatar
    Te best way to reduce this radiation is to use the phone less and stay away from towers completely. Remember the inverse square law of doubling the distance to quarter the power.
    AHHH i feel like im in my principles of radiography 2 class again!!! The inverse square law is different for my use, we need 4x more mAs to penetrate when we are doubling the distance!(which in essance is saying the same thing, we need more KV and more mAs to adequately penetrate the part - the farther away the SID the less power behind the radiation).

    I hate the laws of radiation....too much to remember You should be more worried about how many CT scans and xrays you have. One abd/pelvis CT is comparable to over 400 xrays!

    Anyways, i'm out of school for the day so no more radiation thinking from me
    Last edited by ShortStop51001; 01-13-09 at 06:12 PM.
    01-13-09 06:09 PM
  15. BBartist's Avatar
    actually the radition emmited from the phone will eventually cause a benign bluetooth tumor to grow right on the inside of your ear!

    honestly never thought about something like this...then again now that you think about it my head does hurt when I sit realllllly close to the microwave!

    -just messin
    01-13-09 06:52 PM
  16. Username00089's Avatar
    I'm seriously not smart enough for this thread....
    01-13-09 07:13 PM
  17. xxxxpradaxxxx's Avatar
    So is it true?

    Do VZW phones emit more SAR than other companies?

    And How Much does the Storm emit in comparison to the 8830 and 8330?
    01-13-09 07:56 PM
  18. Mamaluka's Avatar
    Prada, I've read stories on this very website that had top 10 Lists of worst phones in this area. The number 1 (highest output of rads) was the Verizon Curve followed by sprint curve. The iphone was in the top 5.

    Posted from my CrackBerry at wapforums.crackberry.com
    01-13-09 08:52 PM
  19. jprint714's Avatar
    If you look on CNET and other sites that list SAR levels, you will see that many RIM phones emit some of the highest levels. Hence the query that started this topic. Again, I'm very fond of the RIM phones but would like to explore ways of mitigating this exposure. That's all.
    01-14-09 11:27 AM
  20. invisionz's Avatar
    Throw the phone away and get some soup cans and string. Flashbacks of being a kid ; )

    Posted from my CrackBerry at wapforums.crackberry.com
    01-14-09 11:59 AM
  21. xxxxpradaxxxx's Avatar
    Does the Level of SAR attribute to Cell Phone Call Quality?

    IE A High SAR Makes for Better Call Quality?

    Or No?
    01-14-09 02:48 PM
  22. Pete6's Avatar
    Pete6 is correct. The only way to reduce exposure is to apply the inverse square law. Create more distance between you and the source. You can do this by using bluetooth, or speakerphone.

    Gadgets don't work unless they get hot in use or have a grounding path, the RF energy they might absorb has to go somewhere. This is basic Physics 101, you can't destroy energy, only convert it to a different form.
    You make 2 very good points. Allow me to retort .

    All electrical things work by having two poles. A battery has a positive terminal (pole) and a negative terminal (pole). Often the negative is the ground. It is just the same with radiating antennas. There is the radiating part and the groundplane. Tower antennas have a real grounded groundplane. phones do this atrificially and siply create a different in potential between the two poles of the antenna. It would be much better if every cell phone had a good solid ground connection. This would be somewhat impractical.

    The phone, not being able to leak to ground just sits there radiatating from every metal part. This includes wired headsets/headphones. It does not include bluetooth with its much lower power.

    As branta say, energy cannot be destroyed so the radiated energy is simply absorbed by objects nearby. It simply heats up your ear by a tiny amount.

    Early research was based purely on this phenomenon - heat. However more recent research has shown that the radiation itself causes symptoms in about 1 in 1-10000 people who experience very mild symptoms (mild headachers, mnausea, etc). Of these mild electro-sensitives, about 1 in 1000 of these are very or chronically sensitive to the radiation and suffer any number of nasty physical effects. A very, very, very few (I stress this) have contracted fatal symptoms. I am an engineer, not a doctor and I will not go further. IF you do not suffer symptoms, then my GUESS (and it is only that) would be that you may make reasonable use of your phone with impunity. If you suffer hearaches or any of the other documented symptoms then you should at once, change the way you use the phone AND seek immediate and competent medical attention.

    It is like anythng else, if there is discomfort, stop doing it. We all move away from very loud noise or strong smells. It is just the same with your phone. If it causes discomfort, change your habits.

    LAstly there is a community in Sweden where a number of hyper-electro-sensitives live and this village has no elecro-radiating applicances at all. Residents claim that their symptoms have entirely vanished.
    01-14-09 03:10 PM
  23. Branta's Avatar
    You make 2 very good points. Allow me to retort .

    All electrical things work by having two poles. A battery has a positive terminal (pole) and a negative terminal (pole). Often the negative is the ground. It is just the same with radiating antennas. There is the radiating part and the groundplane. Tower antennas have a real grounded groundplane. phones do this atrificially and siply create a different in potential between the two poles of the antenna. It would be much better if every cell phone had a good solid ground connection. This would be somewhat impractical.
    You seemed to miss my point, although what you say is broadly correct. The grounding I had in mind is the grounding of a screening plate, like a partial faraday cage. If there is no grounding to the screen it simply re-radiates the incoming RF. This makes those clip-on mesh ear screens and similar "RF reducing" devices more or less useless as RF protection, although they might block a few greasy earmarks and they are really good for the seller's profit.

    The phone, not being able to leak to ground just sits there radiatating from every metal part. This includes wired headsets/headphones. It does not include bluetooth with its much lower power.
    To be strictly correct, the human holding an older phone is often the ground counterpoise at cellular frequencies and powers. The inductive coupling between chassis and hand is usually adequate, and completely harmless. The "interesting" emission is still radiated from the antenna, the counterpoise simply provides a stable reference which does not radiate. More of the modern phones seem to be moving towards pcb designs with multiband dipole type antennas which are self balancing.

    Wired headsets shouldn't radiate a detectable signal under normal (non-fault) conditions. The cables are unlikely to be a tuned fractional wavelength so they will have high inpedance, they would only pick up a tiny portion of the RF signal, and they have a huge inductance (the speakers) to increase the impedance even more at cellular frequencies. You know this is true, because the headset doesn't buzz and rattle with the pulsed output signals, and the audio amplifier is not destroyed. And of course bluetooth units are micro transmitters at BT frequencies, but the BT power level is too low to get excited about and the radio link means there is no direct path for the cellular frequencies.

    For the record, I found the BT power level spec.
    Class 1, max 100 mW, min 1 mW
    Class 2, max 2.5mW, min 0.25mW
    Class 3, max 1 mW

    It would be very unusual to find a class 1 headset.

    For comparison, a handheld low band GSM phone will regulate power output between max 2.0 Watts, and minimum 20 mW. High band GSM runs about 3dB lower.

    For 3G equipment this paper http://kom.aau.dk/antprop/pub/ExposureWCDMA.pdf seems to offer a sensible analysis.

    As branta say, energy cannot be destroyed so the radiated energy is simply absorbed by objects nearby. It simply heats up your ear by a tiny amount.
    Lurkers shouldn't get confused about the heating effect. Hot Phone Ear is caused by the phone getting warm because the transmitter is working hard and drawing a relatively high current from the battery. The RF emission does not directly make the phone hot, its the transistors and battery getting warm - the phone is more effective as a hand warmer than as a microwave.
    01-14-09 06:43 PM
  24. Bullfrog110MB's Avatar
    Yeah, lol.

    I might be at risk for brain damage...



    I live in a house with nine working T-Mobile RZR, BlackBerries, Katalyst, iPhone, and some POS old work phone. On top of that I have the T-Mobile hot spot, and three DSL routers because the WiFi works. Roflmfao!
    01-14-09 07:03 PM
  25. senectus's Avatar
    According to the once source of truth ( :-P ) the Wikipedia:
    Specific absorption rate (SAR) is a measure of the rate at which radio frequency (RF) energy is absorbed by the body when exposed to radio-frequency electromagnetic field. It is defined as the power absorbed per mass of tissue and has units of watts per kilogram [1].
    So all in all you'd have to have a thin skull or overclocked phone to get a brain tumor from an FCC rated phone...
    01-14-09 07:13 PM
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