[mythtvnz] Have I got a dodgy DVB-T card?

[Steven Ellis]

On 11/04/2009, at 5:40 PM, James Booth wrote:

> I've been playing around with VDPAU and Freeview HD for a week or so  
> now, and I am starting to come to the conclusion that something is  
> very wrong with my system.
> Initially I had all channels working, but TV3/4 were rough, and TVNZ  
> channels could sometimes be a problem. I was focused on vdpau setup  
> etc and assumed that the various error messages and performance  
> issues I was getting related to problems with this. Indeed, with a  
> bit of playing around things semed to get almost 'good'. However,  
> after a week I have noticed the following:
> 1) Signal strength is always strong, but S/N is sometimes stable but  
> other times all over the show.
> 2) Running a full scan of the transports is very hit-and-miss.  
> Sometimes it will pick up everything, other times it will only pick  
> up one transport.
> 3) Running a transport scan manually specifying the frequency will  
> get a result. But if I then scan the other transports in the same  
> way I get the same set of channels for each transport, as if the  
> card has not actually switched frequencies.
> 4) Once all the channels are configured, often they will not tune  
> properly (only get a partial lock in Live TV). If I go back, delete,  
> and re-scan they will often then work perfectly.
> 5) It may be just coincidence, but it seems that if I get the TVNZ  
> multiplex working the Kordia multiplex will not work, and vice versa.
> 6) A full scan tends to produce a number of extra transport listings  
> with a frequency of zero.
> I am using a Hauppauge HVR-1200. Can anyone suggest what would  
> produce the above other than a dicky DVB-T card? I have a new,  
> professionally installed aerial with masthead amp, so I am working  
> on the assumption there is nothing wrong with that end of things.
> _______________________________________________
> mythtvnz mailin


Try running dvbtune against the various multiplexes and post your  
output. Here's my values which are pretty stable

mythtv at mythtv:~/dvb/dtt$ dvbtune -m 666000000
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()

mythtv at mythtv:~/dvb/dtt$ dvbtune -m 538000000
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()

mythtv at mythtv:~/dvb/dtt$ dvbtune -m 570000000
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()
Signal=38293, Verror=0, SNR=65535dB, BlockErrors=0, ()

Re-check a couple of times to see if after tuning one multiplex  
another multiplex stops working.

Also does the HVR-1200 have a LNA (Low noise amp) like the Nova-T 500?

Steve




Steven Ellis - Technical Director
OpenMedia Limited
email   - steven at openmedia.co.nz
website - http://www.openmedia.co.nz

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