A single noise carrier heard on “our” bands may or may not be causing actual interference. On 30 meters, amateur radio shares that band with commercial users, and they hear us all the time. If your noise goes from S2 to S4, it may be annoying, but the FCC generally would not consider that actionable. It may still be possible to correct the lower-level noise, but it is important to know how the FCC would generally react as you discuss this with a neighbor or utility. The level of noise also gives a very rough indication of the distance the source may be from you. A utility, for example, may be able to locate strong noise on a pole near you, but, though they will try, may have trouble locating a noise that is located a mile away.
It is helpful if you can make audio (.mpg or .wav) files of the noise to use when hunting or getting further assistance.
You can record directly to your computer’s hard disk if you have a sound card, some software and a patch cord. Two good software packages are Total Recorder Standard Edition (shareware, about U.S. $12) or Freecorder (freeware). Freecorder saves audio as good quality MP3 files. Follow these links to download: Freecorder or Total Recorder
Some of what you think are noise may actually be digital signals. Libraries of these for comparison are found on Wikisigs as well as Artemis (for download) sites Some of these may also be found on the ARRL laboratory web site. You may need further guidance to use these effectively and it helps to know what potential generators are nearby your location.
Some inexpensive transceivers and HT’s may have insufficient filtering to prevent out of band signals’ intermodulation products from appearing in the amateur bands. Using a friend’s well-engineered HT or mobile radio to listen for the noise is a good check to make sure the problem isn’t with your radio, especially if the noise is on a single band.
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revised 5/6/23