How to stop knocking in an apartment building.

Hello,

Recently relocated to an old building in San Francisco with steam radiators. Whenever the heat comes on (late in the afternoon and early in the morning), there is incredibly loud banging coming from possibly all of the radiators. It lasts between 3 and 5 minutes, and sounds as though someone is banging on the radiators with a crowbar.

We've tried (when the heat is off) opening the valves all the way and letting out the steam and then shutting them off to no avail. The landlord came out and attempted something to fix them, but it did not work.

2 questions:

1. Is there anything we can do on our own to fix this?

2. Is it possible the problem is in another apartment and there is nothing we can do about it?

Thanks!