Those frequencies listed are the frequencies relative to the 21 cm baseline, of course. We've been listening to a 5 kHz band centered on 21 cm, so we've been lucky so far in that none of the tones has been out of our channel width. The frequencies I gave are the relative frequencies of tones received. It's been transmitted as a series of constant pulses on very narrow channels surrounding (symmetrically, like the messages) the 21 cm band, offset by the amount indicated.