[linux-dvb] Current state of DVB-C support
lyra at pop-pr.rnp.br
Fri Apr 17 21:33:54 CEST 2009
I´d like to share with you my recent experience with DVB-C cards and a
My first attempt to use a DVB-C was with a KNC1 card. I just had to
download the latest source from dvb repository, compile and install.
The card was identified, I could scan channels and watch TV. BUT some
channels works very badly, as the card couldnt lock properly on a few
transponders (309mhz and 321mhz). Running a czap on those channels
shows that the card keep "locking" and loosing the lock.
I thought that the problem could be something with my cabling, so I
tried my card at a friend´s house with the same results. I also tried a
attenuator, but without success too.
On my second attempt I bought a twinhan CAB ci card. Card identified,
but scan didnt worked. Some googleing later, I got it working by
commenting the line 1360 in dst.c (!(state->dst_type ==
DST_TYPE_IS_CABLE) &&). To my surprise this card has NO problem locking
on 309mhz and 321mhz channels. It seems to take a little longer to
lock/changing channels compared to my twinhan DVB-S card (I´m comparing
apples and oranges, right?), but so far it´s working ok.
My third attempt was with a technisat cablestar HD2 card. I used the
mantis repository to get the card working (is the mantis driver already
merged with v4l-dvb?). Again, I can scan channels, but the card could
not lock on those Transponders. In fact it also take a lot longer to
lock on a channel, but after it got a lock, it works right.
Since twinhan works fine, I supose that there´s no problem with my
cable/splitter. Also, I supose that the chance of two disctinct broken
tuners is low. A recent thread on TT-1501 shows that, if I understood
it right, there´s a kind of table where a power level is set to each
frequency range. Is it possible that my two cards didnt worked on those
especif transporders because of this kind of setting?
I´m not a dev, but I would like to help to debug this. How can I help?
POP-PR - RNP
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