{"id":1000,"date":"2009-05-11T10:55:09","date_gmt":"2009-05-11T09:55:09","guid":{"rendered":"https:\/\/www.tomfotherby.com\/blog\/?p=1000"},"modified":"2012-12-07T08:27:49","modified_gmt":"2012-12-07T08:27:49","slug":"nova-td-500-tuning-issues","status":"publish","type":"post","link":"https:\/\/www.tomfotherby.com\/blog\/index.php\/2009\/05\/nova-td-500-tuning-issues\/","title":{"rendered":"Nova-TD-500 Tuning issues"},"content":{"rendered":"

\"attenuator\"<\/p>\n

I wanted to watch freeview on my PC so I bought a brand new Hauppauge Nova-TD-500 card. Unfortunately I found the picture quality to be exceptionally low – There were significant image artefacts and glitches where everything is fine if I plug the same cable into a normal TV. I tried a whole load of things but the solution was to buy an attenuator. Without the attenuator the card was useless.<\/p>\n

\"nova-td-500_boardremote\"<\/p>\n

For reference, this was my “why isn’t my nova-t 500 card working” checklist:<\/p>\n

    \n
  1. Is there a problem with the co-axial cable? No<\/strong> – because if I plug it directly into TV (i.e. not via PC) I get a good picture.\n
  2. Is the signal too weak? No<\/strong> – because I tried a antennae signal booster -> No luck.\n
  3. The Nova-t 500 has two inputs, am I using the right one? Yes<\/strong>, I tried pugging the co-axial cable into socket 1 then socket 2 then socket 1 and 2 at the same time using a cable splitter – I get different results depending on what socket I plug the coaxial cable into but nothing solves the issue. For reference, If I plug it into the bottom input (the one closest to the IR port) I seem to get a slightly better signal on one tuner but ZERO-SIGNAL on the other but if I plug it into the top input I get equally poor signal on both tuners.\n
  4. Is it just a problem with the software \/ application rather than the hardware? No<\/strong>, I tried DVB in different applications (I tried Kaffeine and Xine as well a MythTV) -> All give bad TV image.\n
  5. Is my computer configured okay? I looked at whether DMA is on -> Yes, I’m using a SATA HDD. I checked that we’ve got the latest card firmware (\/lib\/firmware\/dvb-usb-dib0700-1.20.fw<\/code>). I experimented with the “force_lna_activation” and “buggy_sfn_workaround” module options -> No luck<\/strong>.\n
  6. Is my computer fast enough? I compiled MythTV with VDPAU and checked CPU usage with “top” -> CPU usage is <5% so no performance bottleneck. VDPAU is only useful for HD content anyway??\n\n\n
  7. Is there a problem with my card? No<\/strong> – I took it back to the shop and bought a 2nd one but got the same results. (opps!)\n
  8. Is there a problem with electrical interference? I tried using electrical insulation tape in all places where the metal in the PCI card might be touching the metal of the PC case. Yes<\/strong> – This actually did help a bit which means that perhaps there’s some kind of EM interference inside the PC? Doesn’t this indicate a poor design by Hauppauge?\n
  9. Is the signal too strong? Yes<\/strong> – because I tried a attenuator and it fixes the problem. \ud83d\ude42 I guess the Nova-T card was being swamped and couldn’t pick out the digital signal from the analogue signal and other “noise”? With a variable attenuator you can gradually reduce the signal intensity – I think the idea is to find the correct intensity where the signal noise has dropped below the threshold that the Nova-T digital tuner can “see”. I don’t know why my cable has so much noise? Perhaps because it’s at least 20m long and runs parallel to the mains electrical circuit?\n<\/ol>\n

    Additional actions you can take to get this fiddly Nova-TD-500 card working (relevant to UK Freeview television using a roof mounted aerial and coaxial cables<\/em>).<\/p>\n

      \n
    1. Minimise the number of connections between the Nova-T card and the aerial. Each connection reduces the signal strength. I prioritise the Nova-T over other TVs because the other TVs don’t seem so fragile:\n