Two mornings in a row, different stations have QRM'd my QTH hundreds of miles away with readable CW at 60Hz across the entire 160m band. These were in pursuit of the Brunei DX-pedition running this week. Both stations have QRZ pages, only one, though with an email (which I contacted without reply). The other has no email link, but a photo of his 2.5kW dummy load. Both stations were S9-plus on two consecutive days when 160m was otherwise rather flat. So I'm asking, perhaps, an obvious question. Will this broad-spectrum 60Hz QRM for individual stations on a rare-DX freq be most likely do to something amiss with each station's power amp?