Try listening openly to HF/VHF/UHF frequencies on a borrowed scanner sometime. Be not surprised on how often the scan stops on weird ■■■ modulated and regular pattern transmissions that are just garbage from all manner of digital equipment and cheap import electronics of highly dubious TA/compliancy markings (assuming they were ever subjected to any verifiable testing).
PLC’s (power line converters, not programmable logic computers used in industry) are some of the worse offenders in terms of how much and how widely they create harmonics that have near zero suppression for, on HF buy I’ve seen examples generate harmonics of a substantial (and totally inexcusable degree) level well into lower UHF and some even managing to hit SHF territory and be identified easily.
Don’t even get me started on what ■■■■ simple DECT and other standard cordless digital phones generate. And they are mandatory TA items ffs.