ARRLWeb: "Intruder Signal" on 40 Meters Remains a Mystery for Now
NEWINGTON, CT, Sep 9, 2004--An unidentified signal that's been showing up on the 40-meter phone band on or about 7238 kHz has mystified amateurs in the western US and Canada, where it's been heard frequently for the past few weeks. Although it resembles a steady carrier, a closer inspection suggests that the intruding signal actually is a series of closely space signals.