After taking a basic signals & systems class and learning about the frequency domain, I started wondering:

###How the heck do scientists still communicate with Voyagers I and II??

 
Do they send/receive signals in a frequency that is otherwise unusually silent? If not, then how do they send and receive faint signals from something 10 billion miles away, when the spacecraft has so little energy and where it seems practically impossible to aim everything 100% correctly (since things are so distant and moving at the same time)?

(I wasn't sure what to tag this, so please retag as appropriate, thanks!)

After taking a basic signals & systems class and learning about the frequency domain, I started wondering:

How the heck do scientists still communicate with Voyagers I and II??

 
Do they send/receive signals in a frequency that is otherwise unusually silent? If not, then how do they send and receive faint signals from something 10 billion miles away, when the spacecraft has so little energy and where it seems practically impossible to aim everything 100% correctly (since things are so distant and moving at the same time)?

(I wasn't sure what to tag this, so please retag as appropriate, thanks!)