On 08/13/2007 10:31 PM, Manu Abraham wrote: > 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 .. I don't know where you live. In The Netherlands, with a 64cm dish (which I have), only in heavy storm the signal isn't strong enough. Occasional rain is no problem here. > > >>>> 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. Both are possibilities, I have no idea. > > >>> 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 Sorry, I've been pretty frustrated with the dish myself. It's hard to get on the roof here (usually have to wait a couple of weeks every time for dry weather that lasts so the roof isn't slippery wet anymore), and every time the KNC1 gave a bad signal I got back up on the roof and tried to align it better. Now that I've figured out the KNC1 will maybe never give a good signal, at least not with the current drivers if that's the problem, I'm a bit frustrated.. All that time on the roof was wasted. So yes I'm a bit frustrated about that, I shouldn't project it on you.. _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
