Interference Requirements for Homebrewed Transmitters

[kml183]

I am just I am trying to find information about filtering requirements for harmonic interference for transmitters. I am located in north america.

I want to design and build a LPF for my DRA818v radio module (https://www.tindie.com/products/dorji_com/ham-amateur-radio-module-dra818v/). I need to filter out the harmonic components on transmit for 144Mhz. I just don't know by how much!

I have my ham license but unfortunately I don't have my study booklet. I can't find the regulation for this in the FCC guidelines. Any thoughts?

[xrunner]

It's in Part 97, if I am understanding your question.

§ 97.307 Emission standards.

(e) The mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency between 30-225 MHz must be at least 60 dB below the mean power of the fundamental. For a transmitter having a mean power of 25 W or less, the mean power of any spurious emission supplied to the antenna transmission line must not exceed 25 µW and must be at least 40 dB below the mean power of the fundamental emission, but need not be reduced below the power of 10 µW. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement.

[kml183]

Awesome that is exactly what I was looking for! Thanks!