Motorised system setup help required

[sajbyjaan]

Hi,
I have a STAB HH90 motor, a 90x80cm off set dish which I am trying to set up for motorised system. I am located in Glasgow, with the following coordiates obtained from the STAB website
Latitude=55.9N
Longitude=4.3W
Dish Elevation for HH90=37.2

I have installed the mounting pole adjusted it to make sure it is vertical. set up the motor to the specified latitude of 55.9 deg, but I am completely lost with this Dish Elevation 37.2.
The scale at the back of my dish is graded from -5 to +25 degrees, so I am unable to set the 37.5 degree elevation. Am I reading this wrong and should it be a diffent value and if so how do I calculate the dish elevation for my location to have the system up and working.
Thanks in advance.

[Yorks]

Hi sajbyjaan. Wecome to the forum.

I'm not familiar with your motor, but usually there is a declination angle, which you need to subtract from your elevation angle of 37.2, to give you the dish bracket angle. Have a look in your motor instructions to see if there is anything specified.

Yorks

[sajbyjaan]

Hi,
Thanks for the reply and being a newbie I don't quite know what this declination agle is. Anyway the Stab motor manual gives a formula for calculating the dish elevation as follows:-

Deg. of Dish Elevation=P-(45-lattitude) where

P=degrees of dish elevation for a fixed mount given by the manufacturer.

Since I don't know who the manufacturer of dish is I don't have the P value. As I noted in my original post my dish is 90x80cm offset type so how do I go about finding the P value. Is the P value just the offset value of the dish?
Any help appreciated.

[Robbo]

Hi,
Rather than trying to mess about with numbers, you can get the correct dish declination by adjustment.

Initially place the dish so that it looks vertical when you are at 0 degrees. When you are trying to make adjustments for getting the arc, on your nearest due south satellite, you can adjust the dish declination/elevation then for max signal.

I had to do this when I first set up my 90cm on a motor as I did not have a P either.

[sajbyjaan]

Thanks, I will have a go this weekend and let you know how I got on.

[Yorks]

Hi,
I had to do this when I first set up my 90cm on a motor as I did not have a P either.

Better if you can manage without a P when setting your dish up

[Topper]

Better if you can manage without a P when setting your dish up

I could have bet money on that comment arriving soon

[sajbyjaan]

Hi,
Thanks for all your 'helpful' comments, I have set up the dish in the manner described below and ask for some more help:-

Initially set up the dish on a vertical pole without the motor to get the correct dish angle and pointed it roughly towards Astra. Once this had been done I noted the angle marked on the graded scale at the back of the dish, 0 degrees, and proceeded to install the STAB HH90 motor.
Instructions for installing the motor stated that I should adjust the rotor to an angle of lattitude for my location, 55.9 degrees, this is an angle clockwise from the horizon or 34.1 degrees anticlockwise from the vertical.
Now by taking away the 22 degrees offset of the dish from 34.1 degrees I adjusted the angle of dish to roughly 12 degrees and pointed the whole assemly towards south.

Went to the receiver setup chose Astra and motor setup for USAL and dish stated to move towards Astra position. After it had stopped got nothing so proceeded to move the dish manually until I got the signal saved the position and tuned in all the channels.
Then chose Hotbird the dish started to move and once it stopped I got no signal, moved the dish manually through the receiver setup until I got a signal, saved it and proceeded to tune in all the channels.

I have tried to do the same for Eutelsat, Eurobird, etc but nothing, no signal even when moved manually. Where am I going wrong?

I also noted that when I change from say watching a channels on Hotbird to a channel on Astra the dish moves but not to the saved position, but when I turn off USAL and turn on the DiSEqC the motor goes to my saved position.

Any ideas as to how I can further tweak my setup to receive the other satellites up there.
Thanks.

[rolfw]

USALS is designed to move your dish to where it thinks the dish should be according to your coordinates and where you have set your default satellite, whereas DiseqC 1.2 will go where you tell it to, I would stick with the latter.

I'm not a lover of using an off centre satellite for alignment, we have a lot more members with problems using this method, than we do with members using the nearest due South satellite method.

[Robbo]

Hi,
It is best to adjust the dish elevation, motor azimuth for a satellite at the centre of your arc.
(which for the full east-west swing is your nearest due South satellite)
Unless your'e not bothering with west, I wonder why you have done it for Astra (1 ?).

Anyway, adjusting using Astra 1 should get better results than you have got.

When adjusting, it is not good enough just to get a signal, you must adjust adjust to get the MAXIMUM signal, to ensure that you are aimed right in the centre of the beam. This can be checked once you've bolted everything up by slightly flexing the dish (up down) (east west) and see that the signal doesn't improve.


As for the USALS Diseqc anomaly, I suspect that you have not entered you co-ordinates in to receiver, it needs to know your location for USALS to work.

[sajbyjaan]

Hi,
Thanks for the quick replies, much appreciated. Just to clear up a few things mentioned in the above replies, I used a sensitivity meter to home in on the Astra 1, played about with the dish until it gave me max strength, and on the receiver Signal Quality meter is showing 90-93% so I must be near to spot on.
I have entered the coordinates for my location into the receiver setup for USAL obtained from the Stab website, Lattitude=55.9N and Longitude=4.3W for Glasgow City so the motor should move close to the preset positions.
Is there anything else I can do to get the other satellites?

Thanks in advance.

[Yorks]

Not sure whether you are confusing the 2 protocols. Although I am not familiar with your receiver, AFAIK you can't save your USALS position, as they are preset positions set up in your USALS/Satellite menu. You can only change them by altering the preset angle in these settings - which shouldn't need to be done if your dish is set up correctly. It is only a way of fiddling a poor installation.

If you are going to use USALS then try the following:-

Once you have maximized your signal strength by rotating your motor assembly around your pole, and by altering the elevation of your dish using your dish clamp, for your chosen satellite, tighten everything up, and recheck. If you now select a different satellite, the motor should move to the correct position.

Saving positions is normally an option for Diseqc 1.2 only.

Yorks

[sajbyjaan]

Hi,
OK I understand the difference between USAL and DiSEqC now.

So let me get this right, with everything clamped up, including the motor assembly, I should isolate the the motor initially from the receiver, make the necessary adjustments to get the maximum signal strength, say on Astra 1, reconnect the motor to the receiver and choose another satellite, say Hotbird, and USAL settings should take the dish to the correct position.

[Yorks]

With everything clamped up and your receiver set to USALS, select the satellite you want, and the dish should go to that position. Now slacken the motor assembly from the pole, slacken the dish clamp to allow vertical adjustment, and rotate the whole thing until you get your strongest signal. You may need to move the dish in the vertical plane to get a signal. Tighten the motor back onto your pole. Tighten the dish clamp. Recheck signal. If you are using a signal meter, then switch off receiver when connecting/disconnecting. You should now be able to choose another satellite and your dish should go to the correct position. Some receivers allow you to specify USALS or 1.2 settings for individual satellites. Make sure all satellites are set to use USALS.

Yorks.

[Robbo]

If after you've done what Yorks has said and you're still not getting it,
there is a method to check what your arc's doing. I can't remember where I saw it now though.

But basically using graph paper (or spreadsheet graph) you plot what your arc should look like ( elevation on vertical axis, azimuth on horizontal).

Then you move the motor around the arc and measure how far off your elevation is. This will enable you to plot your arc. How the arcs compare will tell you whats wrong:-

one arc above/below the other -- elevation wrong
One arc steeper than the other -- motor latitude/elevation wrong
One arc offset horizontally from the other -- motor azimuth wrong.
One arc skewiff with the other -- pole not vertical.
A comination of all four --- you've really bu99ered it up.

Never had to do this myself, as fortunately my house faces perfectly south, and worked fine when I first put it up with the motor bolted directly to the wall ( lack of time).

[rolfw]

As I mentioned in my earlier post, it is better to tune your dish on your due South satellite, I really cannot see the point of buggering around on 19E, unless your due South satellite is obstruced by something.

Using USALS, send your dish to 5 West and fine tune on that satellite, providing your mast is plumb and your motor elevation is set correctly, you will be pretty much spot on for the rest of the arc.

[Robbo]

@rolfw

[sajbyjaan]

Hi,
Thanks for the suggestion rolfw, since I am a newbie to the motorised systems I did not know where to begin. I just followed the instructions and hoped everything would work out. How wrong was I?
I was at the point of giving up until you threw some light on the matter. You mentioned I should point my dish at the most due south satellite instead of Astra 19E. Can you tell me which one I should be pointing to from my location in Glasgow.
Thanks.

[Yorks]

As your Longitude=4.3W then 5W is your nearest due south satellite.

Yorks

[sajbyjaan]

Hi,
OK looking at the chart provided by STAB website the stored satellite positions indicate the Telecom 2B,2D satellites located at 5W. So I should head toward these as my starting point. Please correct me if this is not so before I start messing about on the roof again. The weather isn't too kind right now so I want to be sure before I embark on another excercise.
Thanks all.

[Yorks]

Using USALS, send your dish to 5 West and fine tune on that satellite, providing your mast is plumb and your motor elevation is set correctly, you will be pretty much spot on for the rest of the arc.

Yep. As rolfw says here

[Robbo]

Hi,
OK looking at the chart provided by STAB website the stored satellite positions indicate the Telecom 2B,2D satellites located at 5W. So I should head toward these as my starting point. Please correct me if this is not so before I start messing about on the roof again. The weather isn't too kind right now so I want to be sure before I embark on another excercise.
Thanks all.

Flysat and lyngsat both list Atlantic Bird 3 at 5W.
11591V loooks strong with FTA channels on it too.

[sajbyjaan]

Hi,

Of the 28 satellite positions pre-programmed into the HH90, Atlantic Bird at 5W is not one of them. However if I go to the one listed at 5w I should hopefully be able to get a signal from one of them and make the necessary adjustments to get the max signal.

Since the weather is abysmal I dare not go up onto the roof so this excercise will have to wait for another day.

Thanks all.

[mashster]

Any Luck? I have just bought myself one and have not even bothered installing it yet ... As I have to psych myself up first!

This seems like mission impossible!

Hi,

Of the 28 satellite positions pre-programmed into the HH90, Atlantic Bird at 5W is not one of them. However if I go to the one listed at 5w I should hopefully be able to get a signal from one of them and make the necessary adjustments to get the max signal.

Since the weather is abysmal I dare not go up onto the roof so this excercise will have to wait for another day.

Thanks all.

[Tivù]

It's a doddle if you are patient and methodical

Mind you, the Post you are replying to is over two years old - maybe he's still up the ladder!