On Mon, 7 May 2007, Thomas Kaiser wrote: > Trent Piepho wrote: > > I looked at the code again, and I mis-read the budget-ci DVB-C tuner, it > > should have been: > > budget-ci DVB-T 195 1/8 MHz > > budget-ci DVB-C 160 MHz (wrong!) > > ttusb-budget DVB-T 195 1/8 MHz > > ttusb-budget DVB-C 236 1/8 MHz (wrong?) > > > > In other words, DVB-C was 160 MHz when it should have been near 200 MHz. > > > >> Anyway, this > >> http://linuxtv.org/hg/v4l-dvb?cmd=changeset;node=e7c424bbf9aa;style=gitweb > >> change is wrong anyway and should be reverted. > > > > You're right, reverting this change will make it go from 160 MHz to 200 MHz. > > > > It still looks to me like the ttusb-budget driver has the bug in the DVB-C > > td1316 tuner code, as it switches at 236.13 Mhz where as all the other td1316 > > code uses 195 ~ 200 MHZ as a switch point. > > > > > > Yes, the bug is still there in the ttusb-budget tda1316 tuner code. My > patch (it wasn't really a patch :-( ) was applied to the wrong file. > > One thing I don't really understand. Why do we have to add the IF > frequency to determine the frequency for the band switch (it's a long > time since I repaired televisions)? No reason, it shouldn't make any difference. if(x < 159) is mathmatically the same as: if((x+36) < (159+36)) It's just an arbitrary choice if you should define the bands before or after the IF offset is taken into account. The bug in ttusb-budget looks like it came from someone cut&pasting code without taking this into account. > When I look in the docs of the tuner, it is written: > Low band 49 to 159 MHz > Mid band 162 to 444 MHz > High band 448 to 862 MHz > > This is the "Channel center frequency including tuning margin". Are the docs available somewhere? I couldn't find them on google. _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
