[linux-dvb] Re: DST & Twinhan-Card

[Craig Read <craigread@csi.com>]

Manu Abraham wrote:

> On Wed November 17 2004 8:47 am, Craig Read wrote:
>  
> > Stefan Schenk wrote:
> >    
> > > > said to be a 100% clone of Twinhans VisionDTV. I can load the drivers
> > > > and everything looks perfect. The problem is, that i get a very bad
> > > > signal in (vdr's femon-plugin shows someting between 15% and 30%) and
> > > > therefore the picture is very very bad.
> > > > When i start the card with the same antenna in the same room under
> > > > windows i get a full signal and a perfect picture.
> > > >
> > > > Do you have any idee whats wrong with my system or my card ?
> > > >
> > > > Thanks a lot
> > > >        
> > I have exactly the same problem on my Twinhan VisionDTV here in
> > Australia.  The MythTV setup program reports ~23% signal strength, I get
> > 2/5 channels ok (ABC and SBS), but everything else is totally
> > unwatchable.  The same card works reasonably under Windoze (>80% signal
> >    
> The signal strength indicator is just a gimmick, it has nothing to do with the 
> actual signal strength, i believe.
>
> What are the values you see when you *zap ?
>  
Thanks for the response Manu.

I actually resolved my reception problems with this card via a 
combination of installing the latest KnoppMyth (R4V5)on a fresh drive 
and then installing the 2.6.9 kernel.  I haven't worked out if anything 
else has been broken in the process yet, but I now have a picture (with 
varying reception quality) on all channels.  Some of the SD channels 
still break up a little worse than my Teac STB, but almost all of the HD 
channels are watchable on occasion (something the Teac STB fails at).

Anyway, my tzap output on one of the "poor" channels is:

root@mythtv:/usr/src/linuxtv-dvb-apps-1.1.0/util/szap # ./tzap TEN\ Digital
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 711500000 Hz
video pid 0x0200, audio pid 0x028a
status 1f | signal 3c00 | snr 5c00 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 3c00 | snr 5800 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 3d00 | snr 5900 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 3d00 | snr 5700 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK

Compared to the output on one of the "good" channels:

root@mythtv:/usr/src/linuxtv-dvb-apps-1.1.0/util/szap # ./tzap ABC\ TV\ 
Melbourne
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 662500000 Hz
video pid 0x0200, audio pid 0x028a
status 1f | signal 3e00 | snr 5700 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 5000 | snr 5600 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 5000 | snr 5600 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 5000 | snr 5600 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK
status 1f | signal 4f00 | snr 5700 | ber 00000004 | unc 00000000 | 
FE_HAS_LOCK

Even though my mast head amplifier is turned up all the way, the signal 
strength still isn't great.  But I'll be installing a new phased array 
antenna, upgrading my cable to quad shielded rg6 and replacing all my 
connectors with F-Type over the next week or so.  Hopefully, that will 
make a heap of difference to the signal.

> > strength, HDTV is unwatchable and channel 10 gets a glitch every minute
> > or so).  This is running under Knoppmyth with the 2.4 kernel.  I also
> > have a Teac STB which works well on all channels (but not enough singnal
> > for HDTV).  I'm about to try loading Suse 9.1 on a fresh drive with 2.4
> > kernel and a fresh CVS checkout of the dvb drivers.  If that doesn't
> > work, I'll sell the Twinhan card on ebay and buy a DVico FusionHDTV
> > (unless somebody suggests a better DVB-T card).
> >    
I tried Suse, but gave up after a couple of hours of playing with the 
drivers.  Since I have KnoppMyth configured correctly, I may give Suse 
another try.

Thanks to everyone on the list.  If it wasn't for seeing other people 
persevering and overcoming these sorts of problems (combined with my own 
stubbornness), I might have actually given up.

Cheers,

Craig...