Ed & Brian, My father had severe health consequences from working in a classroom with operating military radars!
Since the adoption of OET 65 in the late 90s, all licensees (including Hams) have had the responsibility to insure their station is in complete compliance with RF exposure limit guidelines. Most likely during your last license renewal or application for a new license, you checked a box stating you would insure compliance with non-ionization radiation limits. Those guidelines are contained in bulletin OET 65. For Hams OET 65 Supplement B (https://transition.fcc.gov/bureaus/oet/info/documents/bulletins/oet65/oet65b.pdf) gives us some shortcuts to insure compliance without the tedious calculations. Many of the tables were provided by ARRL & the W5YI Group. There are also calculators available on the internet to make it quite easy. Googleing "amateur radio oet 65 calculator" returned many to choose from. The only caveat I will give is that most of the shortcuts and calculators are for a single transmitting antenna at a specific location. Multiple radiating antenna WILL change the protection distances - Field Day & group contesting come to mind! Use to be we had to submit OET 65 compliance statements when licensing all transmitters for Broadcast Stations ranging from 150 MHz to 23 GHz. I believe we finally could use just a blanket cover statement ; but it has been a while since I licensed a non-Ham transmitter. You do need to insure you are in compliance - to protect your family, friends, neighbors and yourself. 73 George AI4VZ From: brian "Considered dangerous" isn't quite right. The jury is out of the exact danger levels of RF for all the various frequencies. These distances are more of an accepted limit that protects you from inquiries regarding RF exposure. Pointing to the distances being met helps get you off the hook. People will be surprised to see how small the distances these calculations are-- especially at lower frequencies. One note often overlooked. The distance is defined as the distance from feedpoint (usually center) of the antenna. Also the duty cycle can be considered in the calculation. There are stock duty cycles for SSB and CW given in the documentation. Antenna gain may have to be included. It used to be that anything at 100 watts and below at HF was exempted. I believe that has changed. 73 de Brian/K3KO On 4/7/2017 16:06 PM, Edward R Cole wrote: > In the USAmerica ham's now have the *responsibility* of determining the > safe operating zones for each antenna per FCC regulation. I doubt many > ever do the calculation. Fortunately Australian ham Doug MacArthur (sk) > VK3UM (a well known eme'r) has written a program which you can download > for free. I will simulate the emf fields base on your input data like > antenna, power, height, band and produces the legal exclusion zones > where RF exposure is considered dangerous. > > http://www.vk3um.com/emr%20calculator.html > > Its not hard to use and provides some interesting if not surprising info > about your station safety. > > As I already stated, it is the legal requirement for all US hams to have > evaluated safe range for humans before operating. > > Eg: half-wave dipole, 1400w, line loss 0.5 dB, 14.2 MHz: exclusion = > 3.06m radially; safe height 2.60m for FCC. Also provides ARPNSA and CEU > radiation limits. > > 73, Ed - KL7uW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
