Author Topic: VDR t500 signal strength  (Read 718 times)

jayzee

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VDR t500 signal strength
« on: November 18, 2008, 03:30:53 pm »
Hi,

I have been experimenting with VDR since the fix to allow md's to watch TV. I have a nova t500 and have previously had this working under mythtv, at the time I noticed that one tuner on the t500 would find loads of channels and the other only a few.

Since trying on VDR I can setup the core and I can find 34 channels when doing

sudo scan -o vdr -p -u /usr/share/doc/dvb-utils/examples/scan/dvb-t/uk-WinterHill > channels.conf

and I then managed to setup an md and copied across the channels.conf file. this resulted in me being able to watch any of the 34 channels on my MD as well as on the core.

Very pleased with the work Andrew and the rest have put into getting this to work my next stage was to work out why i am only getting 34 channels.

from my previous experience with mythtv i tried the same scan command but forced it to scan using the second tuner

sudo scan -o vdr -a1 -p -u /usr/share/doc/dvb-utils/examples/scan/dvb-t/uk-WinterHill > channels.conf

this time I got 87 channels - is it possible that one tuner is more sensitive than the other?

currently I have a high gain digital aerial, but at the moment it is mounted in the loft for ease, I am now thinking that i am going to have to get it fitted on the roof to get a strong enough signal for both tuners to work

I tried uploading the new channels.conf with the 87 channels through the admin page and then tried watching tv on the core but this just brought up a pixelated image that after a few seconds disappeared and seemed to make VDR crash. I also tried copying the channels.conf file to the MD and then restarted everything, but this just seems to have broken the MDs tv.

I assume the first instance of TV takes up the first tuner, so if the first tuner can't find the channel in the channels.conf that the second tuner setup there is going to be issues?

I have now tried to go back to scan using the default tuner and now only get 16 channels and now I can;t get even these 16 channels to work on either the core or the MD even after a reboot of everything.

I already have a booster on the aerial, but it looks like I may have to get the aerial put on roof:( to sort my issue out? and even then I am unsure why I am having problems getting back the 34 original channels

thanks


J
 
Core/hybrid
Asrock AM2NF3-VSTA, AMD 64 Dual Core 4000, 1gig ram, 2xpvr150, 1xwintv nova T500, 1xconextant 4x security cam input card

1 X MD
Asus M2NPV-VM, AMD 64 3200, 512mb ram, Silverstone Lascala LC02B

3xMD
Biostar 200n, AMD Sempron 2300, 512

totallymaxed

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Re: VDR t500 signal strength
« Reply #1 on: November 18, 2008, 05:38:16 pm »
Hi Jayzee,

Did you add the following to /etc/modprobe.d/options   ?

options dvb-usb-dib0700 force_lna_activation=1

This will turn on the onboard amplifier and give you better signal strength. After adding the line above make sure you do a 'cold reboot' (Power off... wait a few mins then boot up again)

All the best

Andrew

Hi,

I have been experimenting with VDR since the fix to allow md's to watch TV. I have a nova t500 and have previously had this working under mythtv, at the time I noticed that one tuner on the t500 would find loads of channels and the other only a few.

Since trying on VDR I can setup the core and I can find 34 channels when doing

sudo scan -o vdr -p -u /usr/share/doc/dvb-utils/examples/scan/dvb-t/uk-WinterHill > channels.conf

and I then managed to setup an md and copied across the channels.conf file. this resulted in me being able to watch any of the 34 channels on my MD as well as on the core.

Very pleased with the work Andrew and the rest have put into getting this to work my next stage was to work out why i am only getting 34 channels.

from my previous experience with mythtv i tried the same scan command but forced it to scan using the second tuner

sudo scan -o vdr -a1 -p -u /usr/share/doc/dvb-utils/examples/scan/dvb-t/uk-WinterHill > channels.conf

this time I got 87 channels - is it possible that one tuner is more sensitive than the other?

currently I have a high gain digital aerial, but at the moment it is mounted in the loft for ease, I am now thinking that i am going to have to get it fitted on the roof to get a strong enough signal for both tuners to work

I tried uploading the new channels.conf with the 87 channels through the admin page and then tried watching tv on the core but this just brought up a pixelated image that after a few seconds disappeared and seemed to make VDR crash. I also tried copying the channels.conf file to the MD and then restarted everything, but this just seems to have broken the MDs tv.

I assume the first instance of TV takes up the first tuner, so if the first tuner can't find the channel in the channels.conf that the second tuner setup there is going to be issues?

I have now tried to go back to scan using the default tuner and now only get 16 channels and now I can;t get even these 16 channels to work on either the core or the MD even after a reboot of everything.

I already have a booster on the aerial, but it looks like I may have to get the aerial put on roof:( to sort my issue out? and even then I am unsure why I am having problems getting back the 34 original channels

thanks


J
 
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jayzee

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Re: VDR t500 signal strength
« Reply #2 on: November 18, 2008, 06:28:14 pm »
Hi Andrew,
thanks for the reply, I will try when I get home.

although I was under the assumption the on board amplifier was now turned on by default when installing the latest lmce with a t500, but if it isn't that could well be my problem :).

regarding having problems when trying to update the channels.conf and getting vdr to work again, I have read vdr can be a bit funny accepting changes to the channels.conf file and can take a few reboots to update - is this correct?

I was also wondering what is the best way to update the channels.conf on the core and the md's and for the changes to take effect, do I always have to use the web admin page to upload it or can i just copy it to the required location for the core and mds and then reboot everything? - so far I have only managed to get channels.conf setup correctly the first time, if I try to change it vdr seems to get confused.

thanks

J
Core/hybrid
Asrock AM2NF3-VSTA, AMD 64 Dual Core 4000, 1gig ram, 2xpvr150, 1xwintv nova T500, 1xconextant 4x security cam input card

1 X MD
Asus M2NPV-VM, AMD 64 3200, 512mb ram, Silverstone Lascala LC02B

3xMD
Biostar 200n, AMD Sempron 2300, 512