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RF Exposure Calculator:

Vernon Mauery (N7OH) on August 23, 2010
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A while back, when I was dreaming about where to put my antennas safely, I did a lot of research about radio frequency exposure. I poured over OET Bulletin 65, which details the FCC's limits on human exposure to RF electromagnetic fields. They have formulas and tables and forms to fill out. It is all wonderful and fine, if you live in the 1960s. Welcome to the 21st Century. We live in a world of computers to do all that number crunching for you. I looked around for any web-based things that would help, but the closest I could find was the power density calculator written by W4/VP9KF. This is fine if you want to do it for EVERY band on EVERY transmitter each time you make a change to your station.

To make a long story short, I decided to write my own web application that would do all the work for me. Because it is a web application, I can share it with everyone else. Here it is: N7OH RFE Calculator. I have gotten a lot of praise for it so far among my friends and was urged to push it out to a wider audience. I hope it does as much for you as it has done for me.

It use HTML5's local storage capabilities, so you must be using a fairly new browser (Firefox 3.5, Google Chrome 5.? , IE 8, etc.) It saves all your data on your computer so my server doesn't need to save it for you. This means no login so it is even easier to use.

The basic premise of the calculator is that you have transmitters, antennas and connections. Transmitters each have one or more bands, defined by power, mode, and usage. Antennas each have one or more bands defined by gain. Connections connect the transmitters to antennas and are the place where losses get factored in: tuner loss, transmission line loss, etc. Add these all together and you get to see some detailed results about your station.

Member Comments:
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RF Exposure Calculator:  
by AB8AL on August 24, 2010 Mail this to a friend!
Doesn't seem to do anything. Says Error on Page.
RF Exposure Calculator:  
by KC2SYK on August 24, 2010 Mail this to a friend!
Nice tool, very easy to use. Thank you for releasing it under the GPL! 73.

-Chris KC2SYK
RE: RF Exposure Calculator:  
by N7OH on August 24, 2010 Mail this to a friend!
I am unable to test using IE (I only run Linux, no Windows here) but I know it works in FireFox 3.5 and Google Chrome 5.
RE: RF Exposure Calculator:  
by KC2SYK on August 24, 2010 Mail this to a friend!
IE8 doesn't have any HTML5 features. It doesn't work on IE8. No big loss, no one should be using IE anyway.

-Chris KC2SYK
RF Exposure Calculator:  
by NA4M on August 25, 2010 Mail this to a friend!
WM5R wrote an RF Safety calculator some years ago. He released the code into the public domain and a version of it now lives at:

73 Phil NA4M
RE: RF Exposure Calculator:  
by N7OH on August 25, 2010 Mail this to a friend!
My biggest issue with the other existing RF safety/exposure calculators out there is that I had to enter things in one band at a time and they wouldn't remember things from one visit to the next. I wanted something that would let me see all my results at once and would save them from visit to visit so I didn't have to retype everything.
RE: RF Exposure Calculator:  
by W5GNB on August 25, 2010 Mail this to a friend!
I am running an old XP-pro machine with IE-8 and all works fine here.
Thanks for the link !!!!

Gary - W5GNB
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