"Compare this to the inverse field you get from 100 mW into a half wave dipole, which would be 138*SQRT(.0001)=1.38 mV/m@1 mile. 100 mW into a quarter wave monopole typical of AM BC stations, 192*SQRT(.0001)=1.92 mV/m@1 mile. Obviously not permitted under Part 15, but when people hear "100 milliwatts", that's what they think."
This is what 100 mW at full efficiency with a reference antenna for AM and FM. Part 15 devices have HUGE efficiency losses with the approved antennas, and usually the input is much less than 100 mW.
Tom Kneitel had a circuit for an open air AM BC "Campus Limited" station back in the 1960s. I forget what the antenna was like, but the RF output was only 400 microwatts to comply. The circuit had to be approved and a certificate signed by the holder of a Second or First Radiotelephone License. I'll look when I find my copy of his book.
This is what 100 mW at full efficiency with a reference antenna for AM and FM. Part 15 devices have HUGE efficiency losses with the approved antennas, and usually the input is much less than 100 mW.
Tom Kneitel had a circuit for an open air AM BC "Campus Limited" station back in the 1960s. I forget what the antenna was like, but the RF output was only 400 microwatts to comply. The circuit had to be approved and a certificate signed by the holder of a Second or First Radiotelephone License. I'll look when I find my copy of his book.
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