On Freitag, 21. März 2008, Oliver Endriss wrote: > Hi, > > Manu Abraham wrote: > > Hi Hartmut, > > > > Hartmut Hackmann wrote: > > > This might be right! I could not get good information regarding the > > > transponder bandwidths. We might need to make this depend on the > > > symbol rate or a module parameter. > > > > You can calculate the tuner bandwidth from the transponder symbol rate > > (in Mbaud) for DVB-S: > > > > BW = (1 + RO) * SR/2 + 5) * 1.3 > > Apparently I need some lessons in signal theory. ;-) > What does R0 stand for? > > Do we have to select a higher cut-off value to compensate for the LNB > drift and other stuff like that? > Zarlink zl1003x datasheet (avail on net) tells this: fbw = (alpha * symbol rate) / (2.0 * 0.8) + foffset where alpha is roll-off 1.35 for dvb-s and 1.20 for DSS The manual suggests to use highest possible bandwidth for aquiring a lock. And after that read back the offset from the demod and adjust the tuner then. Regards Matthias -- Matthias Schwarzott (zzam) _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
