From the ARRL... The FCC recently sent advisory notices to several hams who may have caused QRM on their transmitting frequencies while operating split to work SSB DX on 40 meters. The complaints stemmed from operations during February. "While this may not have been malicious interference, please be advised that amateurs must operate in accordance with Section 97.101 of the Commission's rules, which sets out the general standards for operation of an Amateur Radio station and specifically covers frequency sharing and interference," FCC Special Counsel for Amateur Radio Enforcement Riley Hollingsworth wrote. Since most of the rest of the world only has access to 7.000 to 7.100 MHz--still in the US CW subband--US stations working 40-meter SSB must listen for DX stations in the US CW band while transmitting "up" within the US 'phone allocation.