What is the optimal satellite signal quality for Freeview?

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GamerOC

439 posts

Ultimate Geek

#86558 8-Jul-2011 13:35

Hi there everyone at Geekzone, Im writing this post with the purpose to find out your opinions and experiences in regards the signal strength and signal quality you get through Freeview sat.

Im currently running freeview from my DIY pc build HTPC and I have notice that some of the channels jerk or have like a dvd when scratched kind of bad performance despite other channels looking quite good.

this is what im getting at the moment:

Signal strength 94-96%
Signal quality 55-68%

I thought that was ok enough to watch digital tv with good quality picture however some channels like stratos, C4, shinetv, U tv are not sharp clear?? however TVNZ7 and tv2, 3, 1 and even prime are sweet 4ss but Prime lags or jerks i dont know the word to discribe it.

In your opinion or experience what is the optimal signal quality that I should be getting for cristal clear image.

thank you,

Andy

openmedia

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#491080 8-Jul-2011 13:52

Sounds like skew. Your strength is high but your quality is a little off, hence you are getting some MPEG issues on Prime.

As to overall picture quality, some of the channels will appear a little soft due to the compression levels in use.

Generally known online as OpenMedia, now working for Red Hat APAC a Technology Evangelist and Product Manager. Still playing with MythTV and digital media on the side.

password1

64 posts

Master Geek

#491122 8-Jul-2011 15:07

What do people use to measure signal strength and quality? I'm using mediaportal 1.0.3, which unless I tell it to re-tune all the channels, I'm not able to find out the strength or quality (unless I'm missing something). Thanks, and sorry if off-topic

mm1352000

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#491152 8-Jul-2011 15:40

Do you mean MP 1.1.3?
If so then you should be able to get strength and quality readings by using the "manual" section in TV Server configuration or right click + select "tuning details" when watching live TV. The values are meaningless from an absolute perspective ("50% quality" means nothing because... well, what is it 50% of?) but you can at least use it to determine whether signals are weaker or stronger from day to day. Anything more than that is guessing, and you should really get a professional in to measure BER (bit error rate), SNR (signal to noise ratio) etc...

mm

GamerOC

439 posts

Ultimate Geek

#491163 8-Jul-2011 16:10

so
mm1352000 so are you saying 50% is not enough for smooth picture?
I will climb the roof now and see i can raise the quality signal is i can.

Brunzy

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#491164 8-Jul-2011 16:11

As mm.. says , they are only a rough guide.
If your S&Q are not up to scratch you will soon know ,as it may drop out in light / medium rain

ZollyMonsta

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#491175 8-Jul-2011 16:20

I notice there is also some strange interlacing issues going on with U and TVNZ7 on Freeview Sat.

Media DevOps Engineer (TV) @ Vodafone
Check out my LPFM Radio Station at www.thecheese.co.nz

password1

64 posts

Master Geek

#491261 8-Jul-2011 20:11

Thanks mm. Yes MP 1.1.3
Signal level and quality are both zero for SBS for me. :(
Signal level is zero for TV 3 etc, but 100% for strength.
One and TV 2 have no issues.

mm1352000

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#491267 8-Jul-2011 20:36

@GamerOC: my comment was more directly addressed at password1, but it may also apply to your situation. The Freeview satellite signal is relatively strong, at least compared to the SBS signal. It is hard to tell from your description whether you're experiencing signal problems or codec problems, especially since you claim that a mixture of channels on both transponders are okay while others are not.

@password1: receiving SBS requires a stricter dish alignment. You may find that the skew on your LNB is not quite right. Fine (5mm or less) adjustments can be made to try to improve the situation.

password1

64 posts

Master Geek

#491271 8-Jul-2011 21:02

mm1352000:

@password1: receiving SBS requires a stricter dish alignment. You may find that the skew on your LNB is not quite right. Fine (5mm or less) adjustments can be made to try to improve the situation.

Thanks again mm. I've been messing up my strengths/qualitys/levels terms

SBS fluctuates from 0 to 100 in signal level (usually 0), but stays on 0 for quality. I've just tweaked the lnb and it made no difference to sbs, but made the tv 3 level go from 0 to 100. Giving up for the night.

GamerOC

439 posts

Ultimate Geek

#491307 8-Jul-2011 23:46

thank you guys for your help and I have played with the dish and now is working fine just a liitle playing with it with sat finder. I think the image is very good and im very happy with it.
I also check prime and is better but flicks or i see the picture fragment in to little squares for a quarter of a second then all smooth but only happens like every once and a while.
this weather sucks so i give up on climbing the roof while when and windy so will let you know if i get it sorted,

cheers,

Andy