def calc_n_coarse_chan(self, chan_bw=None):
n_coarse_chan = self.container.calc_n_coarse_chan(chan_bw)<EOL>return n_coarse_chan<EOL>
This makes an attempt to calculate the number of coarse channels in a given freq selection.
            It assumes for now that a single coarse channel is 2.9296875 MHz