I figure someone over here will know how I can fix my silly mistake.  Boy do I feel like a lid...  
Somehow, while futzing with the settings on my DX-398, I accidentally set the third timer.  I have no flipping idea how I managed it, but now every day at quarter to twelve (1645 or so Z), the darn thing kicks in and starts playing 100.1-ish FM!  
Anybody know how the heck I cancel it without losing all my other settings?  I've tried a few things, no joy.  *facepalms*