What kind of things I could "see" with an amateur radio telescope?

From my simplistic analysis, it's not good for much.

For comparison, the first radio telescope was 9 meters.

One of the favorite parts of the spectrum for radio telescopes is the water hole - 21 cm.

From my quick mental arithmetic, this dish would be able to resolve sources of 21 cm signals of they were about 5 degrees apart.

I'll update with links and more when my computer is working; this is written on my phone :-)