Ah, well...each station is ordinarily on a separate wavelength. It's sort of like...

[He crouches down and draws a sin wave in the sand.]

This is one frequency. [He draws several more next to it, of varying wavelengths and amplitudes.] And these are others.

[Then he draws another one, and another, and another, all in the same spot. By the time he finishes, it's impossible to make out any individual waves.]

And this is what's happening right now.