In this setup, we will be recording 8 spectra simultanously. Pairs of spectra will cover both
polarizations collected by the LBW-receiver, set over 4 staggered frequency ranges (bandpasses)
of 25 MHz, each of which is sent to a separate WAPP "board". To accomplish the overlap of frequency
bands, we set the "rest frequencies" of the four bandpasses to 1415.4058, 1395.4058, 1375.4058 and
1355.4058 MHz, corresponding to WAPP boards 1 to 4, respectively.
The true rest frequency of the HI line is, of course, 1420.4058 MHz.
Note that the frequency decreases from Board 1 to Board 4.