For the past few Sundays I've noticed that in the early morning the AM 690 signal is much weaker than it usually is. In fact before 7 am it appears to be weaker than that of KFBK or KGO. My observations are strictly anecdotal. All I know is that I have to turn up the volume on my trusty Grundig compared to the level I have for the rest of the week.
What's going on?