On 8/14/07, P. van Gaans <w3ird_n3rd@xxxxxxx> wrote: > On 08/13/2007 09:55 PM, Manu Abraham wrote: > >>> Can you describe the problem that you face ? other than low SNR ? ie > >>> have you checked whether your cables are okay, Dish is aligned proper > >>> etc etc ? It will help to avoid a lot of frustration later. :) > >>> > >>> > >>> Manu > >>> > >> That's great! > >> > >> The problems I face: I have a lot of BER, measured with femon -h (with > >> my patch applied for decimal readings). The sky is clear. Visiosat Bisat > >> G3C dish. > >> > >> On ZDF on Astra 19,2 east (Astra 1), I see nothing (and I mean > >> _nothing_) but green and purple blocks and loud aliens in my speakers > >> constantly. BER is into 65000. > >> > >> On Omroep Brabant on Astra 1D at 23,5 east, I see some bits from the > >> image but constantly lots of complete stripes with corrupted MPEG, and > >> the audio is also bad. So this stream is also corrupt. BER into 65000. > >> > >> Now ZDF is one of the weakest transponders on 19,2 east and Astra 1D is > >> old so doesn't perform optimal either. But this is not normal. > >> > >> On BBC One/Two/Three/Four on Astra 2D, and that beam is strong in my > >> location, the picture is good most of the time, but once approx every > >> minute a small visible corruption passes by. Just as long as it does > >> _not_ start to rain, I can follow the program. BER into 65000. > > > > > > I understood your problem. > > > >> On the Dutch channels on Astra 1 at 19,2 east again, like Nederland 1 at > >> 12515.25 H (Astra 1G) or RTL 5 at 12343.50 H (Astra 1H) the picture is > >> perfect, and BER hoovers and shows 0, 256 or 512 (which is low). > >> > >> There are also values in between. n-tv on Astra 1 at 19,2 east shows > >> around 17000-18000. Perfect picture. > >> > >> But.. When it starts to rain, the whole party is over. > > > > > > During rain, don't expect anything much with DVB-S > > With just a little normal rain, DVB-S should work fine. Only when > there's hard rain and it's seriously cloudy you could expect the picture > to actually fail with a properly set up dish. Overall DVB-S is very > reliable. DVB-S is also used as a feed for many cable channels in The > Netherlands, and they hardly ever fail. > By rain i meant, by the rain we have here, we don't receive any DVB-S. Don't know how many cms of rain .. > >> So that's my problem. When I swap the KNC1 for my Technotrend S-1500, > >> all the channels work, including ZDF, perfectly, and the BER is zero > >> everywhere, even ZDF works with zero BER. There are many other channels > >> that do not work but I couldn't possibly list them all, I don't think > >> that would make sense anyway. And sure, there could be a little > >> difference in tuner quality and stuff in favor of the Technotrend, but I > >> really don't believe it would be that big for cards from the same price > >> range. And it's not like Philips is a bad or cheap brand either. > > > > > > Though i am not saying it is bad, devices designed improperly leads to > > bad results. However good the components are. We have examples, but > > not stating that is the case here, but a possibility. > > Yes, that's true. > > > > > > >> I'm actually not sure the SNR number in femon is low, I was really > >> talking about Signal to Noise ratio - with all that corruption and > >> horrible performance it has to be bad. > >> > >> On Windows, I can watch ZDF with the KNC1, but I see some "error" level > >> in the Windows software, that "error" most likely means BER. But it's > >> not much. Last time I checked anyway, it's been a while since I've seen > >> Windows. > > > > > > If this is an overall problem that you see, then it has nothing to do > > with the drivers. I thought in your case, the driver was misbehaving > > It's not an overall problem, I only have this problem with the KNC1 card. Maybe it is a hardware specific problem, 2 options again * The card type as a whole is bad * The specific mentioned card has a hardware problem. > > > > The TT card you have behaves similarly ? > > The TT card performs fine, I still have to test it in somewhat harder > rain, but the fact it shows ZDF perfectly without even BER is a huge > difference. > > I also have a Vantage standalone receiver. I did test that one in rain, > and ZDF would just keep going. > Ok, so your dish/LNB setup is fine, then. > > > >> The problem seems to be getting worse, because some days/weeks ago I > >> believe I had zero BER at the Dutch channels, and now it's around > >> 256-512. But the weather, temperature and other stuff also varies, so > >> it's always hard to say. > > > > > > Maybe it has something to do with your dish alignment, LNB alignment > > etc ? A LNB skew can cause a lot of errors to happen, eventhough the > > dish is aligned correctly. > > > > Trust me, I know stuff about alignment. I have re-aligned the dish 5 or > 6 or more times and _every_ time the result did not fully satisfy me. I > changed the height of the dish, how deep the LNB was into the holder, > the skew, tried moving the LNB holder up and down (possible on my dish), > I tried everything. Even swapped the LNB's, but that made no difference > either. The last couple of times, I took my laptop up on the roof so I > could VNC to my desktop and see the signal/BER instead of using the > cheap satbeeper. Then I swapped the card for the Technotrend, and > checked the status... Heeeeey... No signal trouble? Ok. Cool down > But OK.. The Common Interface on the S-1500 is totally not detected, > dmesg never heard of it, it's really like it isn't there, and it's > required for the Dutch channels. So my choice at this moment is a good > signal but no Dutch channels, or a crappy signal and Dutch channels. > > So what do you do then.. > Ok, finally back to square one S-1500 issues. I don't have a clue yet on this, i saw some long long threads, but that's it. I think some people had success with the patches floating around, but seems you had bad luck with that as well. Aargh! _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
