Le 15.06.2008 13:20:30, Ales Jurik a écrit : > On Sunday 15 of June 2008, Dominik Kuhlen wrote: > > Hi, > > > > On Thursday 22 May 2008, Ales Jurik wrote: > > > Hi, > > > > > > my friend told me that he is sometimes able to get lock by > decreasing > > > (not increasing) the frequency. Yesterday I've tested it and it > seems to > > > me he was right. So I'm able to get (not very stable, for few > minutes) > > > lock as well as by increasing and by decreasing frequency of the > same > > > channel (EurosportHD). > > > > The derotator code in the stb0899 seems to be setting the initial > frequency > > to the lowest search range and never changes this (as it should > increase > > steadily to find a lock) > > > > > It was also detected (not by me, I don't have riser card) that > when the > > > card is connected not directly into PCI slot but with some riser > card, > > > the needed difference for getting lock is higher (up to 10MHz). > So > also > > > some noise from PC is going into calculations. > > > > > > I don't think the problem is in computation of frequency but in > for > > > example not stable signal amplitude at input of demodulator or in > not > > > fluently changing the gain and bandwith of tuner within the band. > As I > > > see in the code some parameters are changing in steps and maybe 3 > steps > > > for whole band is not enough? Especially in real conditions (not > in lab)? > > > > Could you please try the attached patch if this fixes the problem > with > > nominal frequency/symbolrate settings? > > > > Many thanks, but I don't see any improvement. Minimum time after I've > lock is > 150s. > > The only improvement was done 2weeks ago when Manu Abraham fixed some > headers > with register addresses. From that time it is possible to get lock > also at > problematic channels but very unstable. > > But I've found that all channels with lock problems are DVB-S2, 8PSK, > FEC 3/4. > So all channels broadcasted in QPSK is possible to tune without > problems and > also channels broadcasted in DVB-S2, 8PSK, FEC 2/3 are possible to > tune to > without problems. Channels in DVB-S2, 8PSK with different FEC (to 2/3 > and > 3/4) I was not able to test. For me adding 4MHz solved the lock problems for DVB-S QPSK FEC 3/4, but did not solve my problems for a DVB-S QPSK FEC 5/6. I will try Dominik's patch to see if it improves things. Stay tuned (oh well) Bye Manu _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
