Last night I was hearing something on 530, just on a boombox in my bedroom, but didn't stay to try to figure out what it was. I've heard stations on that frequency for years, I think there was a college station from Toronto there in the past.
I've also seen Radio Locator listings for low power broadcasters that have local strength service out to a half mile, then secondary service for ten miles or more, because the groundwave propagation is so good at that low frequency.
Another thing is, at least in the past, schools and drive-in theaters were using 530, lots of carrier current use there. Highway Advisory Radio, HAR has used 530 too, so there are probably lots of good DX opportunities there.
Ainmal