I haven't really listened to 900 MHZ yet, although I did take a quick look up
there as I was interested in fast-scaan ham tv, (pun not intended) none of
which I saw on any of the ham bands that my scanner is capaable of picking up.
400 MHZ, 90 MHZ, 1240-1300 MHZ, and 2.4 GHZ.

I read that the 400 MHZ band is the most popular to see ham tv, but I also read
that ham tv and ham radio transmissions are not allowed in the 400 MHZ ham band
in my area of the U.S. Well, at least not a portion of it.

Then after learning how to read sensitivity specs, I decided to start my
scanning on the lower frequencies and go up from there, for my most recent
scanner.

which I will probably start seriously monitoring pretty soon.

I've only just fooled around with it so far, with occasional light monitoring
of various things.