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

Hiya, enthusiasts!

Well, at some point, I hope, my family will have our own place (we live in London) and then I plan to install this piccolo monster I have in the garage...

Currently, I use T90 plus a small dish for 30W, with some 12 LNBs and that's OK for my family...

However, for me this is not ideal, of course, hehe.... Soooo...

I have several questions (other than the central satellite, obviously: Thor or 1,9E?):

1) Do I need a permission to set up 1,5m motorised (probably polarmount?) satellite dish, depending on where/how I install it? As in, on a:

a) house (probably just under the roof, so it can scan as much of the sky as possible [preferable, I suppose]); or an

b) outhouse/shed (kinda much lower); or as a

c) ground installation (cement block in the ground with a large mast, say 1.5 - 2 m high)?

2) Which motor to buy for this beast? I would prefer something capable and sturdy (no plastic cogs, if any, I guess), so what's the best, longest lasting?

3) Do I need another little box, i.e. positioner for it?

4) If I do get an external, separate positioner/driving the dish motor, which will save all the satellite positions it can get to in it, can moving it be automatised, so I don't have to press a special remote for the positioner first, when I want to change a satellite position, i.e. can I only use E2 RCU (I presume so, depending on the positioner box, as it most probably must have USALS code in it but better I ask all the questions...)?

5) If that is possible, how does one set it up inside E2, precisely, please - given I would frequently re-flash my boxes...??? USALS? In which case I should always put the dish into a zero position before I reflash my E2 box or...???

I had motorised dishes a very long time ago (2008 was the last such setup I had) and I suppose things have changed in the meantime, as technology frequently does change fast... Besides, that dish was 1m x 80cm, the motor was not DiSEqC, so I better ask...

Thanx in advance!

P.S. georgeflu and the pros - given your knowledge and experience, precisely with larger dishes, I am hoping especially you guys will put up some good info, links, plus some words of wisdom... :)

P.P.S. I suppose I would need a proper polarmount like this: https://www.gibertini.it/index.php/en/accessori-op150s?id=2 - I can't remember if I bought it with the dish, damn... must go dig in the garage, hehe...

0) Yes, misunderstanding: when I last had a motor it was Superjack polarmount on 100cm x 80 cm dish. And it had a positioner box.

1) Now, we are trying to find a house with a clear view of South (East to West), so I can put the dish up on the garden side...

Probably with plates on either side of the wall, with long and strong screws through the wall, supporting the pole etc.

How high - depends but of course, the best it can be, so dish can travel as much as possible.... We'll see...

2) The Q about the UK laws was for our English colleagues, of course.... ;)

3) So, which Polarmount motor would be strong enough for 1,5m dish? Are they still being made? Which ones are best quality, properly built, no cheap plastic etc.? Any idea? Links, please? And which positioner boxes are best? I had them but long ago, so....

4) Is there a good tutorial for a motorised dish with a positioner box, please? With steps, as to how to set it up, please? Do you know a good one?

5) Misunderstanding again: I will constantly be reflashing my boxes with new versions of E2. Testing, testing, hehe...

But the Q is: before I flash my box, should I first put the dish in the zero position? I forgot how this is done...

Thanx for your time!!! :)

Thanx to a colleague, he reckons 24 inch is better, as it uses less power, so it struggles less = it lasts longer!

https://www.primesat.eu/satellite_dish_actuators_motors.php

Then: http://www.moteck.com/

http://www.moteck.com/ProductD…tegoryId=13&ProductId=296

Found my Gibertini - this one with 2 polarmount motors moving it => higher/lower position, C/Ku-band (2 LNBs):

Higher maths, that, hehe... Intriguing!!!

Also:

I think I have one similar to this:

https://www.viewtech.tv/produc…box-ii-diseqc-positioner/

And a 2.4m beast:

He also sent these to me, saying they are getting harder to find and I know he is right:

http://www.worldwidesatellite.…tore/satellite-motors.htm

https://www.satellitesuperstore.com/vbox.htm

Thanx Antepenultim8 !!!

Thanx a bunch! Any help is welcome!

Not quite 0, though, m8... More like -0.22... And it will change when we find a house to buy... ;)

Most people here go for 0.8W but I can see some are targeting something closer to 1,9E, depending on small variances in their geo position...

Mind you, I will not be doing it - a good pro is a must, at my age....:tongue1: I have EZ-AL bracket of some sort and a good LNB for it etc. But...

Have you seen the clever 2 polarmount setup with Gibertini? I wish I could somehow get that working....

As for external links: I posted what the sponsor does not have, I think, so... :)

Cheers!

Btw, when it comes to Gibertini with 2 polarmount motors...

I presume some positions are only C-Band and might need a different inclination - am I correct in assuming that?

So, one moves the dish to that position with the bigger motor and then, using the other, smaller polarmount motor, one moves the dish up and down to get the C-Band signal, right?!?

I mean, 1,5m dish is not that big, so this correction with the second motor might be required. right?

I presume that with bigger dishes there is no need for that, they can get just about anything as is?

Any ideas?

Nice contribution!

With one correction, from my experience and discussions with installers around EU (as I lived in half a dozen countries)...

Earth has a wobble. So, a really well pointed dish may be slightly off, for 5-6 months of the year.

Even when I was in Sweden, I could see the difference in Thor signal. And the professional setting it up was merciless with precision!m (See the images attached!)

Equally, when I had 1,5m Gibertini pointed at 28E, depending on time of year and day - signal did change, despite precision.

My discussions with users via these fora, also confirmed this, namely that signal varies throughout the year...

So, one reason is some satellites that are not quite in Clark's belt and the other re. Earth's wobble....

Or does anyone have a better explanation?

OKI... It's not like BBC hasn't published articles about this... And I know what I saw and compared to many a hobbyist... So, there are various wobbles our old Earth exhibits (ergo, it's a little dance that satellites and our dishes dance):

"As a result of the precession (a slow movement of an axis of a spinning body around another axis due to a torque such as gravitational influence, causes a change of direction of the first axis) and nutation (a periodic variation in an inclination of an axis of a rotating object) the change of a rotational axis direction occurs."

"Observations show that the figure axis exhibits an annual wobble forced by surface mass displacement via atmospheric and/or ocean dynamics, while the free nutation is much larger than the Euler period and of the order of 435 to 445 sidereal days. This observed free nutation is called Chandler wobble. There exist, in addition, polar motions with smaller periods of the order of decades.^[9] Finally, a secular polar drift of about 0.10 m per year in the direction of 80° west has been observed which is due to mass redistribution within the Earth's interior by continental drift, and/or slow motions within mantle and core which gives rise to changes of the moment of inertia.^[8]

The annual variation was discovered by Karl Friedrich Küstner in 1885 by exact measurements of the variation of the latitude of stars, while S.C. Chandler found the free nutation in 1891.^[8] Both periods superpose, giving rise to a beat frequency with a period of about 5 to 8 years (see Figure 1).

This polar motion should not be confused with the changing direction of the Earth's rotation axis relative to the stars with different periods, caused mostly by the torques on the Geoid due to the gravitational attraction of the Moon and Sun. They are also called nutations, except for the slowest, which is the precession of the equinoxes."

"With these three broad contributors identified, scientists can distinguish mass changes and polar motion caused by long-term Earth processes over which we have little control from those caused by climate change. They now know that if Greenland's ice loss accelerates, polar motion likely will, too.

The paper in Earth and Planetary Science Letters is titled “What drives 20th century polar motion?” Besides JPL, coauthor institutions include the German Research Centre for Geosciences, Potsdam; the University of Oslo, Norway; Technical University of Denmark, Kongens Lyngby; the Geological Survey of Denmark and Greenland, Copenhagen, Denmark; and the University of Bremen, Germany.

An interactive simulation of how multiple processes contribute to the wobbles in Earth's spin axis is available at:

https://vesl.jpl.nasa.gov/sea-level/polar-motion/ "

Wobbly Earth

"Scientists have long known that the distribution of mass around the Earth determines its spin, much like how the shape and weight distribution of a spinning top determines how it moves. Also, Earth's spin isn't perfectly even, as scientists know thanks to slight wiggles in the movements of the stars across the night sky that have been recorded for thousands of years, said Erik Ivins, a study co-author and a senior research scientist at JPL. Since the 1990s, space-based measurements have also confirmed that the Earth's axis of rotation drifts by a few centimeters a year, generally toward Hudson Bay in northeastern Canada."

http://www.bbc.com/earth/story…t-also-shakes-and-wobbles

"Earth is far from stable. Beneath us, enormous chunks of rock are constantly grinding past each other to make valleys, pushing together to form mountains, or dragging apart to create rivers and oceans. The ground under us is forever shifting, stretching and wobbling.

Most of the time, this is nothing to worry about. However, our growing understanding of these phenomena is driving a better understanding of the inner workings of our planet. It is also handy for anyone trying to track and land spacecraft. Here, then, are seven things that make the Earth move for us.

Under pressure

A desktop globe is a perfect sphere, so it spins smoothly around a fixed axis. However, the Earth is not spherical, and the mass within it is both unevenly distributed and prone to moving around. As a result, the axis around which Earth spins, and the north and south rotational poles at each end of the axis, move about.

What's more, because the rotation axis is different to the figure axis around which its mass is balanced, the Earth wobbles as it spins."

New Insight on an Old Wobble

In the process of solving this recent mystery, the researchers unexpectedly came up with a promising new solution to a very old problem, as well. One particular wobble in Earth's rotation has perplexed scientists since observations began in 1899. Every six to 14 years, the spin axis wobbles about 20 to 60 inches (0.5 to 1.5 meters) either east or west of its general direction of drift. "Despite tremendous theoretical and modelling efforts, no plausible mechanism has been put forward that could explain this enigmatic oscillation," Adhikari said.

Lining up a graph of the east-west wobble during the period when GRACE data were available against a graph of changes in continental water storage for the same period, the JPL scientists spotted a startling similarity between the two. Changes in polar ice appeared to have no relationship to the wobble -- only changes in water on land. Dry years in Eurasia, for example, corresponded to eastward swings, while wet years corresponded to westward swings.

When the researchers input the GRACE observations on changes in land water mass from April 2002 to March 2015 into classic physics equations that predict pole positions, they found that the results matched the observed east-west wobble very closely. "This is much more than a simple correlation," co-author Ivins said. "We have isolated the cause."

In Stockholm my T90 was installed during late Autumn/Winter and we had great signal but not so strong later on, the next year... 'till late Autumn/Winter came again....

In Italy - for different reasons - we had that and time of day difference in signal, which was quite stark...

I could go on but...

Spare ram? Arm? Ahem?

Thanx for the C-Band info! I had never had such a beast, so no idea as of yet... :)

If I am very lucky we shall find a house with south facing garden and then I shall seek a permission to put it up sufficiently so it can scan AMAP.... I hope it's not too difficult and their mindsets closed... And if I get it - it'd be interesting with the neighbours... There's always one, isn't there?

You see, with T90 many things are cool and really great but 1W, 5E, 26E, 7/8W and so on I can not get, mostly... Or even 1.9E there are some Balkanic TPs which I can't get here...

Wobble was so frustrating to me, constantly gnawing at installer's ankles - until I informed myself properly and realised, over a period of a few years, that it is periodical. regardless of how perfect the installation is.... I mean, especially with some TPs which are not powerful enough... And one could see the periodic fluctuation of signal of the more powerful ones, too...

We live and learn... ;)

I wish... Last time I had it was in Italy...

Hehe, the dish was bigger than the installer, so he had 2 more people to put it up...:rasta2bigsmoke0gf1:

Poor thing, I gave him a special LNB rail for more LNBs but he was totally out of his depth... Just couldn't even start thinking about it and gave up immediately!

Moreover, he refused to even see my T90:quiet::chuckle::saint: - so I had to do it all myself, heh...:don-t_mention:

Oh, Italy... weird and wonderful, all at once... :hello

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