Hi Patrick,
Thank you for replying. In answer to your questions:
Are you sure it is a driver problem?
No but given the very same device on the very same antenna system works ok
under Windows it seemed like a good place to start.
If the BER stays at this value it could also mean that the
channel-configuration is wrong.
Are you using a channels.conf which has all parameters set, or are you doing
a channel-scan-like tune (all values are set to AUTO).
I have attached a copy of the channels.conf file I have been using. It was
generated by hand based because the scan and w_scan commands would time out for
all stations except C31. The information was obtained from a variety of sources
on the internet but mostly from http://igorfuna.com/dvb-t/australia/ I am
located in Melbourne Australia. Looking in the file you can see that most
paramaters are defined except for inversion which is left as auto.
There are usually some adaptations board-designing companies do to improve
reception quality (adding external LNAs and things like that) that are of
course handled by the Window-driver, because it is created by the
manufacturer and not by the Linux-driver, because (in this case) the driver
was released by the chip-manufacturer.
I agree this could be the case and indeed changing the force_lna_activation
module parameter seemed to do nothing which would make me suspect that the lna
control GPIO on this device is not that same as what is implemented in the
driver. Challenge is there seems to be no information around about the DIB7000
or the MT2266 otherwise I would just trace the connections manually using
device pinouts.
Is the device toggling between FE_HAS_LOCK and no FE_HAS_LOCK or does it
stay constantly at
The device stays constantly on FE LOCK after the initial tune. Attached are
brief snapshots of tuning using tzap for the different frequencies. Whilst this
only shows a few seconds worth of data, the output is more or less the same
over an extended period.
Please try whether you can achieve the BER lowering by moving the antenna or
using a better one. If this helps, it really means that the windows-driver
does something more the board.
Not really practical to move the antenna its up on a mast and indeed as the
existing analogue stations are still transmitting from the same tower I know
that I have a good signal with no multipath. Other TV sets with digital tuners
on the same antenna also report excellent signal levels.
I doubt that the chip-driver needs to be changed, more likely the GPIOs of
the dib0700 (in dib0700_core.c) or of the dib7000 are used to turn on or off
a frequency switch or a LNA.
Yes, I suspect that you are right. Challenge is that without any documentation
on the devices you are flying blind to reverse engineer the design.
Good point, what are the frequencies you're tuning ?
The frequencies I have been tuning are listed below but also of interest is
that they all use 64QAM whereas the station that works uses QPSK which to me
says this is a signal problem and as you state above, probably tied in with a
LNA as QPSK is more robust in comparison to 64QAM which is why it has probably
been used by C31 as they don't have the need for the higher throughput and have
a more modest transmission power compared to the others.So they get more
bang for their buck but have the down side of only a single SD stream.
C31 557.625 MHz QPSK Works ok.
ABC 226.5 MHz 64QAMDoesn't work
7 177.5 MHz 64QAMDoesn't work
9 191.625 MHz 64QAMDoesn't work
10219.5 MHz 64QAMDoesn't work
SBS 536.625 Mhz 64QAMDoesn't work
Happy to hear your or anyone else's thoughts.
Regards
Pete
From: pboettc...@kernellabs.com
To: peter_tille...@hotmail.com; linux-media@vger.kernel.org
Subject: Re: Dib7000/mt2266 help
Date: Sat, 12 Mar 2011 16:47:40 +0100
Hi Peter,
(adding back the list to CC)
On Saturday 12 March 2011 11:48:38 Peter Tilley wrote:
Hi Patrick,
My sincerest apologies for coming to you directly but I have tried the
Linux mailing list and received no response and noticed you seem to have
been heavily involved with much of the Dibcom driver development.
I have an issue with a dual tuner which is sold under the brand of Kaiser
Baas KBA01004 but identifies itself as 1164:1e8c which is a Yaun device
and this device seems to have already been included in the driver files.
It loads ok and reports not problems. It tunes ok and reports FE lock on
all channels however on all but one channel upon receiving FE lock the
BER stays at 1 instead of dropping to a low number which would
indicate I am not getting viterbi.
The device is fitted with pairs of MT2266 and DIB7000 which I have
positive identified by opening the USB stick.
am more than happy to try and work this out myself however the amount of
detail around in support of the Linux drivers is extremely
