Which motor for Gibertini off-set 1.5m dish, please?

There are 35 replies in this Thread which was already clicked 2,560 times. The last Post () by bodger2.

    What I mean is, I could continue putting sources there - but the proof of the pudding is in eating: a number of us saw the same phenomenon and we started talking (I think some feed chasing board) and this was the conclusion, that three different types of wobble (that clearly exist), combined with whatever dance of the satellites up there and who knows what other phenomenon, gave us a headache for a good chunk of the year... Then, good quality would return for the other part of the year...


    Various people, various countries, usually noticing slightly weaker TPs but one could see it in the signal, generally... We are talking a normal weather, nowt to do with clouds!


    But go on, I am all ears, how can you explain it better?

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    • Official Post
    Quote

    Meanwhile, I'll attach some pics of latest nice job I did at end of september.

    KA-band 13.2m dish

    :54_002::bravo: i have got to get me on of those...... as an added bonus the wife would deffo leave me !! :mosking:

    :rasta2bigsmoke0gf1::laugh1::party-time:First win the lottery, then move to Brazil or St. Lucia or suchlike...:beer1:

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    Quote from gorski

    What I mean, I could continue putting sources there - but the proof of the pudding is in eating: a number of us saw the same phenomenon and we started talking (I think some feed chasing board) and this was the conclusion, that three different types of wobble (that clearly exist), combined with whatever dance of the satellites up there and who knows what other phenomenon, gave us a headache for a good chunk of the year... Then, good quality would return for the other part of the year...


    Various people, various countries, usually noticing slightly weaker TPs but one could see it in the signal, generally... We are talking a normal weather, nowt to do with clouds!


    But go on, I am all ears, how can you explain it better?

    Difficult to explain a phenomenon which is only described as a slightly better or worse.
    I'm used to make measurement with dBm and calculate a link budget, no data available equals to just a guessing.

    As first I should know the size of the dish, the level measured and few other conditions, any datas available?
    In earlier post I was describing that the variation can be on the transmit side too not only on receive, more details of the transponder affected would be useful, at least to check if they were excited with SNGs or Teleports, TWT, Klystrons or solid state, manned or unmanned stations, dozens of factors come into play.

    There are entire transponders affected by average temp and having a variable gain due to heat, many, many factors to take account of.

    Keeping the TX station gain constant (and is not, belive me) my best attempt to explain the phenomenon, is that with small home TVRO dishes the orbit variations could only be seen during they extreme position path on long term variation.
    The bird, kept in the position with on board truster is not just steady, it is in costant movement and what has been seen buy feed hunters, has been probably only a long path variation of the orbit, not connected with any precession movement aka known as Earth wobble.
    Meanwhile a couple of pics of the BT era... :wink: I was much younger LOL

    b8e6df644cb84.jpg

    43cb0d.jpg

    • Official Post

    I have seen first hand the db - signal level fall dramatically on feeds, after all we the " hobby viewer " are not meant to be watching those PPV feeds without paying your ££££ $$$$ ....... with biss2 currently rolling out those days will probably be over soon enough. :frown:

    The reduced signal is not an issue if the end user the feed was actually indented for, has a massive dish...... 13m is way beyond hobby level lol.

    I know by direct experience too, many reasons on how and why this can happen.

    I name a few:

    _weather conditions, all tastes, tx side, rx side, control side and all relevant combinations.

    _direct feedhorn sunlight collimation, especially in the winter, last few minutes.

    _line-up errors and mistakes.

    _thermal gain shift, the warmer the equipment, the lower the gain.

    _sng operator needs, too low or too high signal.

    _destinatiin needs, too low or too high signal.

    _transponder density.

    _equipment failure.

    _modulation changes.

    This can happen in various levels and different combinations and on both sides.

    As per the destination of the signal, any dish below 3m diameter is considered not broadcast :eye-tongue:


    Have a nice day!

    To go back to the matter at hand: some more info, thanx to Antepenultim8 , re. stuff that our sponsor doesn't have, like AZ-EL polarmount brackets, polarmount motors and V-Box positioners (2 and 3!):


    http://telesatshop.com/en/dise…aeger-moteck-vbox-ii.html


    http://telesatshop.com/en/dise…eger-moteck-vbox-iii.html


    http://www.creativesatellite.c…-uk/d257_Polar_Mount.html


    What else might I need? Hmmm...

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    Like 1

    Hehe, I know my limits - polarmount is outside those limits...


    Mast you can see in one of the pickies from Italy...


    I will be helping (kinda) but mostly taking pickes!


    :chuckle::tongue1:

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    Like 1
    Quote from Ignax68
    Quote from gorski

    Various people, various countries, usually noticing slightly weaker TPs but one could see it in the signal, generally... We are talking a normal weather, nowt to do with clouds!

    Difficult to explain a phenomenon which is only described as a slightly better or worse.

    You misunderstand: there are stronger and weaker TPs on any satellite position I know of. Anyone in the hobby knows this!


    On weaker ones (which one can watch easily at the right time of year) one naturally notices the lost signal first...


    And generally, at such a time of the year, one notices a fall in signal even with the strongest signals...


    Btw, one tends to get the most out of a satellite position precisely on those weaker TPs...

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    • Official Post

    Yes the site Sponsor dose not go to the required level for Sat dishes / mounts etc etc ....


    Bit of a saving on the mount, hopefully compatible with your dish.


    https://www.ebay.co.uk/itm/Pol…8c5c4c:g:n1sAAOSwi-BeX8qo

    Thanx, I did find it but generally I don't trust eBay, from bidding and uncertainty to returns policy and practices, so I avoid it, really.... Tried and didn't agree with me....

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    Like 1
    • Official Post
    Quote

    On weaker ones (which one can watch easily at the right time of year) one naturally notices the lost signal first...


    And generally, at such a time of the year, one notices a fall in signal even with the strongest signals...



    I have not noticed a yearly cycle, it is an interesting theory though..... i will ask on some of the feed hunter sites for there thoughts on it.....

    But i have seen a daily cycle yes, for example on 7.3west i can only get some TP's at night with a clear sky.

    During the day never, regardless of weather.... but on some clear nights i can.

    What is also evident is that the broadcaster can turn signal levels up or down (confirmed by Ignax68 who clearly knows his stuff )

    Also some sats are at the end of there life cycle, some are slowly declining before they eventually fall out of the arc.

    Recently a new satellite (i think for 5w) arrived at its final position with damaged solar panels, so only a small part of it is functional, far from optimum for a billion dollar satellite lol.

    Yes, while in Parma, for instance, 28E channels (not all of them) were fluctuating daily, as you described - with Gibertini 1.5m...

    "Enlightenment is man's emergence from his self-incurred immaturity. Immaturity is the inability to use one's own understanding without the guidance of another. This immaturity is self-incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore: Sapere aude! Have courage to use your own understanding!"


    http://www.columbia.edu/acis/ets/CCREAD/etscc/kant.html

    The earths wobble when I had a big dish, a 2m Precision using a home made feed on the KU feedhorn. Swedish Microwave depolariser which you could turn for circular polarity signals. Incredible difference it made. swedish Microwave I think magnetic depolariser and Swedish Microwave 0.8 max lnb. Far better signal than this modern stuff. This was for D2Mac which was the golden age for me. At the time I looked into it and the signal getting weaker on some birds was they were old and allowed to go into I think more eliptical orbits which were`nt properly geostationary hence the other motor for inclinined orbit tracking. I just had the Precision std Polar mount and used 12 " and 18 " motors over the years. Trees and the neighbours house let me go about 30 deg east and I think Panam sat at 45 deg West but the dish that far west was pretty well masked. I tended to look at the weak signals and weather made a big difference.

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