picture quality and dish size

DIGITALMAN

DIGITALMAN

Member
My Satellite Setup
70cm black mesh Raven Gemini Dish for Skyplus,Technomate 1600 2CI,43cm Minidish pointing at Hotbird13, for now! upgrading soon...
My Location
S.Yorkshire
Hi, i'm new to this website so here go's,here's are my questions which adult channel provides the best picture quality?.And do i use a 80cm or more size dish for Hotbird13?(i.e to avoid rain fade) plus which is best mesh or a solid dish? Thankyou:)
 
With digital tv, either you get it or you don't, depending on signal strength at the receiver input. If you do get it, then there's no way of further improving reception, ie increasing the dish size will NOT give you a sharper picture!

Many tv sets have a "sharpness" control, which makes the picture look more/ less sharp by differentiating object edges, that adjustment is very much a matter of personal taste.

(there's a marginal signal reception strength, at which the picture starts to "pixilate" into small squares, but it still doesn't get any "less sharp"!).

In midlands I get all (Fta ONLY) hotbird fine on just a 43 cm dish, but that gets dodgy further north, and yes some Hotbird channels might "disappear" in rainy weather, in which case you'd need a slightly bigger dish for them. But try out first, otherwise you might be spending money unnecessarily.

As to which adult channels TRANSMIT the best picture - ie, have the best quality video source material, 'fraid I have no idea at all!
 
OOPS, SORRY, APOLOGY !!!!!

(I've left above post "as was", so u can see what I said!).

Had a brain mixup, and was thinking "Astra1", instead of Hotbird!

ok, Digitalman, my Hotbird reception is "partial" on 43cm minidish, and it will be worse where you are further north, so yes you'd probably need a 60-70 cm dish to "guarantee" getting all Hotbird channels.

However, everything else still applies! It's still worth seeing if you can get the channels you want, before upgrading that dish. For example, you'll probably find you can get all the RAI channels, on only a minidish.

You haven't said whether you're interested in just free to air channels, or encrypted ones (for stronger stuff!). It's my impression that - after about midnight (GMT) - roughly a quarter of the free to air Hotbird tv channels start showing some sort of soft mature content, usually advertising associated (with a few being a bit harder), if that's what you want.
 
You might get some idea of picture quality from the bitrates on linowsat: http://www.linowsat.com/0130/all/0130.shtml the ones I see that sound like adult channels all appear to have pretty dreadful bitrates...
 
DIGITALMAN said:
Hi, i'm new to this website so here go's,here's are my questions which adult channel provides the best picture quality?.And do i use a 80cm or more size dish for Hotbird13?(i.e to avoid rain fade) plus which is best mesh or a solid dish? Thankyou:)
Click to expand...

Depends on your location, if you are in the middle of Europe, 80-85 dish is more than enough, I'm afraid dish size increasing would help in a way as to signal strength from certain Hot bird transponders but it wont prevent signal fading whilst strong rain...
 
There are two items that matter - signal strength and signal quality. Below a certain strength (like 50%) the quality will not register and there will obviously be no picture. Above that strength limit when quality is 10-15% the picture may be pixillated and will be on and off. Above about 20% quality, picture is reasonably stable. Strength depends on the dish size, roughly proportionate to the sq of size (dia). For example increasing the dish size from 80cm to 100cm will increase signal strength by 56% ! Quality is affected by rain, cloud, wind, signal reflection and other microwave source. Hope this helps. Regards, pcd.
 
Thanks for the help so far guys,ok as you can see i'm using a 43cm minidish for Hotbird.I can view about 98% of the channels apart from one or two tv and radio channels which breakup even on a clear day due to low signal.In light rain i would loose Hotbird compelety.So i need a 80/85 or 90cm dish but i will still get rain fade is this correct? also mesh/solid,round/oval which is best for Hotbird.With regard to (straight) mature content content it has to be strong :eek: with in reason of course.Cheers
 
OK, all channels disappearing in rain sounds about right (I only get partial minidish reception, with stronger signal further south, but then that dish is pointing through a double glazed window)!

In which case, you SHOULD be ok with a bigger Sky zone 2 (70cm elliptical Raven mesh) dish, but this can NOT be guaranteed, as it depends on the exact signal strength at your receiver input, so 80 cm round would certainly be "safer"!

Yes, the received signal is proportional to dish area, but that's no good for accurate estimation unless you can calculate the actual signal strengths!

(remember to use proper satellite cable, of course!).

Depends on whether you want to take a small financial risk, as a zone 2 minidish already fitted with lnb would be cheaper than 80cm + separate lnb.

As to the stronger (content) channels, sorry no idea, afraid I'm fta only.
 
Ok then Spiney,on both my two systems i use foam filled cable already.So i will buy a 80/90cm mesh dish and a Sharp 0.2db lnb or Invacom 0.3db lnb.

But as i asked before would it make any difference to the signal (i.e better) if it is solid metal instead of mesh, and round instead of eliptical?
 
well, certainly, "larger is safer" and if you then want to go for other satellites you can, no need to buy yet another dish ..... but, think about the wind!

Generally, consider mesh as 20% worse, you're reducing dish effective area by about that much. However, this depends on make and quality, it's not an absolute rule (in theory, there should be no loss at all!). A metal surface solid dish should reflect at close to 100% effeciency. Bettering that is then a matter of lowernoise lnb, possibly a matched feedhorn, etc .....

0.3 dB noisefigure lnb seems a bit overkill, not necessary for just Hotbird, but it's your money .....

Yes, certainly the cable is very important, otherwise you're just "throwing away" some of the received signal!
 
Ok i understand what you have said,the final question which hasn't been answered yet is,which is better round or eliptical dishes?Thankyou again for your help.:-flash
 
Well, as said, received signal strength is proportional to dish size. However, all dbs satellites transmit with 2 different electric field polarisations, in the Vertical and Horizontal planes (for twice as many channels!). So, if an elliptical dish has a smaller vertical measurment, it won't be as good in that direction, for the V channels, as it is horizontally for the H channels.

(I'm ignoring skew here ...... !).

Elliptical dishes give slightly greater selectivity horizontally, which supposedly makes it easier to "find" satellites when searching, especially if only 3 degrees apart, but can't say I've noticed any real difference!
 
Living where you live, Digitalman I would go for a 1 metre dish if you have the room. You wouldn't need planning permission and those extra cms could make a difference.
 
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