Featured Product Archive
The inventions and products featured on these pages were chosen either for their
uniqueness in the RF engineering realm, or are simply awesome (or ridiculous) enough
to warrant an appearance.
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RF Cafe website visitor
David Burger (VK2CZ / K3HZ) sent me a great
Excel spreadsheet titled, "Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency
Electromagnetic Fields." As amateur radio operators learn when studying to earn
a license, you are required to perform a calculation to verify that the transmitted
effective power radiating from your antenna does not exceed a specified maximum
value in areas where humans have access. David's spreadsheet takes system parameter
inputs and calculates, along with various other values, the minimum required separation
distance for both
controlled and uncontrolled human access. If your antenna is mounted up higher than
the limit distance, then no action is required to keep people away. Otherwise, you
must either erect physical barriers or reduce power output to comply with the maximum
RF exposure limit. Separate worksheets are provided for U.S. (Federal Communications
Australia (Australian Communications and Media Authority -
ACMA), and New Zealand (New Zealand Standards -
I performed a cross-check using the online
Amateur Radio RF Safety Calculator
that is recommended by the Amateur Radio Relay League (ARRL) on the
RF Exposure webpage, and the results
agreed within the accuracy of the precision of numbers that were input. David's
version allows you to enter system parameters in more discrete stages; i.e., transmitter
power, transmission line loss, and antenna gain whereas the ARRL's version takes
just final values. I did not attempt to verify the ACMA or NZS calculations.
Says David, "It is based on electrical field theory math, which goes way beyond
what conventional hams are capable of solving. Hence I figured I'd do my bit with
my skills. I originally wrote it back in 2004, with minor tweaks since. It replicates
all the FCC, ACMA and EMC safe working distances calculations around transmitting
antennas. It is not a thesis, and simply replicates the published standards, which
comprise hundreds of graphs. It is a spreadsheet, with no protections at all, and
each worksheet is a wholly contained page, with visible formulas. The FCC rules
don't quite align with EM theory, but the spreadsheet follows the FCC rules to the
Some nice user-friendly features are used like drop-down selection boxes.
David Burger is graciously making it available
free of charge and can be downloaded
HERE. BTW, is K3HZ a great call sign or what?
Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency
Worksheet Tab: "FCC Sup B to OET B65 Ed97-01" ----- Amateur
Radio RF Safety Calculator
ACMA - Human Exposure to EMR: Assessment of Amateur Radio Compliance.
Worksheet Tab: "Australia - ACMA 2005"
New Zealand - Amateur Radio Service: Self Assessment of Compliance with
NZS2772:Part 1: 1999
Worksheet Tab: "New Zealand NZS2772-1999"
NOTES (for all three worksheets)
Worksheet Tab: "NOTES"
Posted July 31, 2018