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RF exposure question

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KC2ZDE, Dec 31, 2010.

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  1. KC2ZDE

    KC2ZDE Ham Member QRZ Page

    Gentlemen, I'm new to ham radio. I've been using a handheld with a max output of 5 watts connected to a mag mounted antenna on a pizza pan in my shack in the basement. The 2M antenna is on the basement window sill. A poor setup I know. I recieved a mobile 2m unit for Christmas which puts out 75 watts max. In the spring I'm going to go with a roof mounted antenna but until then I want to use the mag mount antenna. Again in the window sill about 2 feet above my head. My Question; Should I be concerned about Rf exposure sitting below this antenna without a car surrounding me for protection? Thanks Guys, Craig in N.Y and enjoying the journey radio is taking me on.
  2. NY3V

    NY3V Ham Member QRZ Page

    According to this online calculator, the answer is YES, you should be concerned!

    Wireless Calculators --> RF Safety

    Controlled Env: 1.389 meters (4.557 feet)

    Uncontrolled Env: 3.087 meters (10.128 feet)
    Controlled Environment : 1.005 mW/cm2
    Is the Controlled Env Area Compliant?: No
    Uncontrolled Environment : 0.205 mW/cm2
    Is the Uncontrolled Env Area Compliant?: No

    Frequency of Operation : 148.000 MHz
    Average Power at Antenna : 75.000 Watts
    Antenna Gain : 5.000 dBi
    Distance from Antenna : 0.610 meters (2.000 feet)
    Estimated Power Density : 5.079 mW/cm2
    Ground Reflections : No
  3. KC2ZDE

    KC2ZDE Ham Member QRZ Page

    Rf exposure

    Excellent web site for RF exposure! Thanks for the reply. I'm definately re-thinking my setup.
    Thanks, NY3V
  4. K9ASE

    K9ASE XML Subscriber QRZ Page

    also your mobile radio may not like that much RF so close. it may shut itself down to protect itself.
  5. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    If you're concerned, lengthen the coax and put the rig farther away from the antenna. It would only take a few more feet to be within the "safe" exposure guidelines.

    I might mention that until the FCC OET published their report and subsequent guidelines, hams never paid any attention to this stuff (and of course many still don't) and I believe the comprehensive list of everyone who ever became ill or died from RF exposure while operating ham equipment can be found immediately following this colon:
  6. W8JI

    W8JI Ham Member QRZ Page

    (Which, while on the topic of names following the colon, reminds me this is Straight Key Night.)

    The only known concern of non-ionizing radiation is actually heating something to the point of cooking. The guidelines have so much overkill that for myself I don't worry at all. Of course we do have to comply with the laws.

    73 Tom
  7. KH6AQ

    KH6AQ Ham Member QRZ Page

    If you can't see it it can't hurt you. And remember I before E except after C...
  8. W2ILP

    W2ILP Ham Member QRZ Page

    RF Hazard Limits remain debatable.

    The IEEE/ANSI RF hazard limits, upon which ham radio hazard limit levels have been calculated, remain debatable. They are based on the possible resonance of human bodies. Because of this body resonance at VHF (such as 2 Meters) is graphed as being much more dangerous than at microwave cell phone frequencies. The hazards are based on thermal absorption (RF heating) but not on the possibility of human cell mutation, which might take many years to become fatal cancers, or on the fact that microwave radiation might enter ones head through eyes, nose and ears. It seem that the limits we use may be either too strict or not strict enough.

    w2ilp (I Like Phones)..and mikes that keep my head away from antennas.
  9. KB3UET

    KB3UET Ham Member QRZ Page

  10. KJ4BB

    KJ4BB Ham Member QRZ Page

    75 watts at 2 feet. I would not do it.
    and I can be pretty lazy just ask the wife.:D

    Just not worth the risk, now or later.

    I have had more RF exposure training from cellular 800 - 900mhz to micro wave to x-ray at 6 mv in the last 10+ years at various companies than I care to count.

    expert/ no. but as informed as I can be. :rolleyes:

    The # 1 warning... Protect your eyes. They are mostly water.
    simple enough even my thick head...:D

    Get the antenna outside. away from your head. distance is good, shielding / barriers are always nice.

    Safety !st. better safe than sorry...:D cheesy but true. :)
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