HFU HF Underground

Technical Topics => Part 15 AM and FM Station Operation => Topic started by: k6sti on June 13, 2021, 0033 UTC

Title: 13.56 MHz Antennas
Post by: k6sti on June 13, 2021, 0033 UTC
Four antennas over three types of ground:


Title: Re: 13.56 MHz Antennas
Post by: Prairiedog on July 16, 2021, 1657 UTC
I appreciate what you're trying to do.  Problem is, the results that your page calls "flawed" are far closer to the truth than your "correct" ones. What you term an "invalid" conversion factor and a "technical error" are in reality the international standard for EMC compliance measurements, not an error on ANSI's part or the FCC's.  This is pointed out accurately, if somewhat wordily, in a July 11 post on the subject in the LWCA message board.
Title: Re: 13.56 MHz Antennas
Post by: Finman on October 08, 2021, 1959 UTC
You need to provide the entire quote...

"Part 15 incorporates ANSI C63.10, which contains a technical error. It says to measure the magnetic field and multiply by 377 to get the electric field. But since the field strength ratio near ground varies widely from this free-space value, the result is invalid."

To over simplify, the point being, "free space value" is not reality in the case of a typical part 15 hifer beacon.