Humax Foxsat signal quality in Spain

Discussion in 'Satellite TV, Sky TV & FreeSat' started by gigaday, Feb 13, 2014.

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  1. gigaday

    gigaday
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    A lot of Spain has just lost satellite coverage, however my neighbour with a 180cm dish is working fine and my setup with 135cm dish is working almost OK.

    I am getting a usable picture on most channels especially at night. Why would nightfall make a difference?

    And during the day everything seems good with a clear sky except BBC1 and BBC2 which pixelate.

    Searching this forum I found this:
    Is what is being said correct?

    I am getting Strength = 85%, Quality = 50% on the channels I have checked. I think I understand that Quality is a measure of how much error correction the receiver is doing, which corresponds to how clean the signal is. So what is Strength? Is it what the person said above?

    Also, from other posts it seems that I may have scope for improving the Quality and my end-user picture by adjusting alignment of dish, skew of LNB or a better LNB - without having to upgrade the dish. Does this sound reasonable?
     
  2. Vin Blanc

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    Fitting a better LNB mightl only make a marginal improvement - hopefully!

    Adjusting the Skew could improve the "Quality" but only if it is incorrectly set in the first place. - see here;- www.dishpointer.com

    I would suggest that you really need a bigger dish (depending on location).

    Vin Blanc
     
    Last edited: Feb 13, 2014
  3. pedro2000uk

    pedro2000uk
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    Interesting as I think it used to be the other way- IMO it is the solar stream's action on the satellite's tx or reflector on the Clarke Belt & that this alters as the Clarke belt turns in relation to the solar stream hence the rise & fall on a daily basis as it receives more or less bombardment. Antenna design has changed though so it may now be more down to the design of the tx bit (primary reflector= Gregorian)).

    [​IMG]
    [photo]
    [​IMG]
    [artist's impression- note the white lnb shaped tx's aimed at the primary reflectors]

    that's what they look like on 2E anyway- the tx bits look like dinner plates covered in bacofoil so would be least affected as the sun sets over the Clarke belt as the UK's tight beam's tx faces east & would get it more as the sun rises over the Clarke Belt (sort of day time Spain)....or something like that

    in some respects & in general yes, some stb's meters do give a relative power level so the quality is relative to the power, a much more meaningful meter reading but most stb's meters or images are just too basic & some just give zero or full for power so quality is overall a better measure on basic stb's meters unless you want to spend on a pro meter.

    Yes- do it all the time, I come across loads of bigger dishes under performing that I can outperform with a smaller dish done really well, it depends if it's all 100% now or there's scope for improvement - there almost always is scope re: the points you've already made & several other issues.
     
    Last edited: Feb 14, 2014
  4. gigaday

    gigaday
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    Thanks for that info Pedro. You prompted me to do a bit more research and I discovered that geostationary satellites are subject to station-keeping, I don't know how often this is needed by I also noted that the satellites start to wobble N-S due to Sun and Moon gravity. This article is interesting
    http://www.satsig.net/satellite/inclined-orbit-operation.htm
    and I saw that it says "VSAT antenna, which sees a big signal drop for a few hours each day when the satellite has moved to the north easterly position" so this could also be a factor in daily signal variations.

    On the signal Strength vs Quality thing. When my STB say "Bad or no signal" both Strength and Quality have gone to zero. I am guessing that these STB meterings are very approximate and only useful as a very rough guide; I can see no difference in Quality reading between a channel that is pixilating badly and one that is a good picture and the Strength on each will be 85%.
     
  5. TJT1

    TJT1
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    Your ref says the drift is about 0.8 degrees per year. If it is needed to keep it within 0.15 degrees, this implies about 5 times a year.
     
  6. pedro2000uk

    pedro2000uk
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    That link looks like it's regarding inclined orbits, they aren't regular DTH broadcasts from a GSO & do vary in position but can still be used for more commercial use rather than dth.

    There are lots of other 'things' that can effect the signal [& the orbit] on the GSO- some irregular, some regular with a daily pattern & it's always interesting trying to figure what's causing up & down signal periods, but the big consistent daily cycle's always been the sun & the solar stream. You could at one time apply an equation in Astra 2D & Nilesat 101 days - [both from designs of before 2000] with all the relevant variables, longitude of the satellite, aim of the beam's reflector etc. etc. & allowing for the time shift on the ground where you are compared to the sat & allow for the solar stream's flow over the ionosphere at the time & it worked well for most satellites but with the latest satellite designs I'd say that needs reworking as it clearly doesn't work for the main reflector for ASTRA 2E .. but does for the Gregorian primary reflector (it would be the secondary reflector if it were an rx dish on the ground btw- eg a Fibo).

    You can calibrate a few stb's meters quite reliably with a calibrated pro meter - but you can hardly expect an stb costing c. £50 to a few hundred to do what a pro meter does costing a lot more.
     

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