Even a device that is compliant with FCC Part 15 they can still tear up the HF spectrum.
This is in FCC OET 63;
"Part 15 transmitters that obtain power from the electrical power lines are subject toconducted
emission standards that limit the amount of radio frequency energy they can
conduct back onto these lines in the band 450 kHz - 30 MHz. This limit is
250 uV will trash the HF spectrum and be perfectly legal.
emissions the standard has lots of different levels for different types of devices. The one that is probably most applicable to televisions is that the limit is 30 microvolts/meter at a distance of 30 meters.
30 uV/M @ 30M is still a signal level of -77.5 dBm. That will effectively knock out any attempts at even moderate signal DX.
Our receivers commonly have sensitivities down around 1-2 uV. We are trying to listen for a mouse fart in a room full of elephants.