Help with HH90 motor/dish setup

S

satlearner

Member
My Satellite Setup
Deltech Bravia STB with USB HDD
Deltech DreamGame STB with USB HDD
1.8mtr mesh dish (C) - will be removing soon
2.4 mtr mesh dish with 24 inch Actuator (C & Ku) (currently installing)
90cm solid dish fixed (Ku) - will be removing soon
120cm soli
My Location
South Africa - GP
Hi all,

I have just completed the mounting of the Stab HH90 motor and dish kit. Now, I read all the manuals, did all the research and still cannot get this right.

Main problem is tracking the arc. The info I found using dishpointer was as follows:

Lat: -26,2102 deg
Long: 28,3026 deg
Motor Latitude: -26,2 deg
Declination Angle: 4,4 deg
Dish Elevation: 41 deg
Azimuth (true): 0,0 deg
Azimuth (mag): 18.5 deg

Now, I have mounted the equipment as per the manuals. I now rotate the entire dish/motor assembly to point at north (i am in the southern hemisphere). I then setup the motor latitude as above info, as well as the dish at 41 degrees. The declination angle i'm not sure about, so if this is the problem, where does it fit into the equation. The dish offset is most likely a standard (26 deg, i think as the only other value i found is 22 degrees on some or other write-up)

I now have the dish pointed at north. The closest satellite that I have selected is Eutelsat W4 (36 deg East). I hope this is the correct one to point to. I then move the dish with a command to the motor and stop at W4, then make slight adjustment to the dish (up/down & left/right). Great, i have some signals on the spectrum. I now command the motor back to the zero position and then request it to move to 68,5 deg East and this is a well known one in SA. I also use this long travel so that I can monitor the spectrum as it moves.

Problem....I see nothing else other than when it passed W4 @ 36E. Can anyone give me a few pointers here. Where am i going wrong?

Thanks.
 
Are you using USALS?

Presumably you are and you sent the dish to 36E?


Then you say, you adjust dish left right, up down.


When you do this part, when doing the left right bit, you move the whole assembly around the pole, the dish must stay perfectly central on the motor tube. Is this what you are doing?


Also the declination is taken care of when you asdjust the dish up and down, the actual figures become unimportant if you set it using your nearest due north satellite.

I assume that your pole is perfectly vertical.;)

Also when on 36E, double check that it is actually 36E by comparing channels and frequencies with lyngsat.com.
 
Hi Robbo,

Thanks for the response. Before I even used the USALS procedure i did used my satmeter to command the various position movements. An example would be if the dish is now at North, I can then request a move to 13 East or 36 East, any position that i'd like it to move to. So basically I requested a move to 36 East. I chack the signal with the meter, I then request NIT info and it ties in with the Sat name. I then go a step further and check the channels and find the same as Lyngsat's info. In the end it is the correct satellite i am pointing to. Now all of this is done with the meter i'm using, so the lnb cable to the receiver is not even hooked up as yet.

If I try the USALS procedure it does the same, as the meter also requests Latitidue & longitude values when setting up to drive the motor.

The pointers as per the Stab manual was followed, esp, the fine tuning of the dish alignment. I keep the dish locked and move the assemble slightly left/right then re-tighten and then try the same with the dish as well. This is done looking at the feedback on the spectrum as well, so I know for sure that i am receiving the best possible signal.

Right now I am looking for any information that I could use when I go up to the installation again. It's a bit of a mission as the installation is on a double storey roof and carting all the necessary tools up + the meter and a power cable in case I am up there for too long....this is the reason why i want to gather all the info so when I'm up there I can try everything and not have to climb up & down too many times....okay, a drink in between is always welcome.

Another question that has just come up....The lnb angle ??? I left this at the"0" mark but had a very bad lnb strength displayed. I rotated the lnb and got to about 60% strength from 35%, so this has helped on the 36 East, but now this will create problems when the dish is moved to another sat. as the lnb skew will be different. Can someone point out the right way to do this.
 
Normally, one would adjust the skew for the closest satellite, it should be around zero.

Then when the dish moves around the arc, the dish also rotates in the vertical plane effecting an approximate automatic skew adjustment.


Some LNBs are known to have a inbuilt skew offset, whereby the coax points vertical but that is not the zero skew position.
 
Hi Robbo,

Okay, this weekend I did some testing. Firstly, I aligned the entire setup as per the info from dishpointer, ie. motor lat = 26,2 deg, dish elev. = 41 deg, LNB at 0 deg. I then also checked the mounting pole, it is perfectly level, checked both horizontal and vertical using a spirit level, so no problem there. I then re-aligned to North using a compass and all refered to the info from dishpointer to confirm.

Next step, I requested the motor to move to 68,5E as I know this sat and the relevant channels available......NO GO - The motot cannot move to this position as the travel limit is 55 deg left/right. So, I then rotated the entire assembly so that the motor at it's extreme (55 deg.) would be at the 68,5E point. Checked signals, nothing found.

I then requested the motor to return back to the zero position and then rotated the entire assembly to 68,5E (as if it were a fixed installation). I then adjusted the dish elevation so that the signal is as strong as possible and took some measurements. I placed a marker on the roof tiles using a permanent marker and measured the following:
1) the height from the tile to the top of the lnb (+/- 520mm)
2) the distance away from the apex of the roof. (+/- 390mm)

Great, i know have some values to work with. I then move the assembly back to North, and the motor back to zero position. I then request another move from zero to 68,5E (remember, the motor will only move 55deg), then rotated the assembly a bit so that the lnb is now as close as possible to the markings I made earlier. I then tried adjusting the elevation close to the values recorded earlier, so that I could get some sort of signal strength to work with. Played around with this and could not get a clear signal. Now I don't understand anymore......the dish is at the similar position is was at earlier so why don't I see anything....Is it perhaps the angle at which the dish & lnb is sitting at???

Okay, the weather is not so great so after being on the roof for almost two hours, I decide to call it a day and move the motor back to zero, move the assembly to 68,5E and adjust the dish to be able to pickup the signals from 68,5E. Tightened all the bolts and got off the roof. Ran a blind scan on the receiver and got all the channels being broadcast on KU @ 68,5E. So, basically, this is now a 'fixed installation' until I come up with some ideas on how to solve this. Kepp in mind that the only adjustments that were made was the dish elevation and rotation of the assembly. At no point in time did I make a change to the motor latitude of 26,2 deg.

Hope this will allow someone to give me some pointers on where I am going wrong.

Regards,
satlearner.
 
Make sure that there are no motor hardware or software limits set in the receiver.

Set the system up using USALS for your nearest due NORTH satellite.


Then use DiSeqC 1.2 , and the east/west controls on the receiver to move and store your satellite positions.

I believe USALS has a built in limit that it won't go past, but not sure what it is as I have never reached it, but it is before it gets to the horizon, I think it is 50 degrees either way.
 
Robbo said:
I believe USALS has a built in limit that it won't go past, but not sure what it is as I have never reached it, but it is before it gets to the horizon, I think it is 50 degrees either way.
Click to expand...


60° limit either end :)
 
Looks like you are ignoring some basic steps and then tying yourself up with lots of spurious detail.

Have you checked out the How to for DiseqC motor setup in the sticky threads at the top of this section?
 
Thanks to all....

*** Please note that the motor was controlled by the Satlook Micro G2 on previous attempts, so the receiver was not hooked up to command motor movements ***

@ Robbo: I have cleared all limits on the receiver, did that twice to make sure it was done. I have setup using USALS, input Lat & Long values. The motor was at zero position when this was doen. The unit was then swiched to DiSeqc and then moved east / west via the remote.


@ satelliteman: You are correct. The max movement east/west is 60 degrees. I have managed to move it to 55 degrees either way. Any more than this will cause the motor to automatically return to zero position.


@rolfw: I have been through the sticky as well as other documents from other sources as I wanted to ensure that I had commonality in all the guidelines. I will however check the sticky once again. If you can think of the basics that I am ignoring, please advise as I know for sure I have done things step by step. There may be a possibility that I have overlooked something. I have drafted a step by step list of what I should do and I followed this each time i tried to set this up and still did not get it right.

I wil try again this weekend if the weather is good and see what else I can come up with. By now my neighbours are probably thinking I am crazy, sitting on the roof each weekend.
 
If the motor can go 55 degrees either side of zero, then you shouldn't have a problem, since tou want to go to 68.5E and you are are already at 28E yourself. So the motor only needs to go to 40 degrees or whatever it is exactly.

So there is nothing to stop it all working properly if the guides are followed.

I have a Stab hh90 here, out of interest I will check later to see how far it will go under Diseqc.
 
I now have the dish pointed at north. The closest satellite that I have selected is Eutelsat W4 (36 deg East). I hope this is the correct one to point to. I then move the dish with a command to the motor and stop at W4, then make slight adjustment to the dish (up/down & left/right). Great, i have some signals on the spectrum. I now command the motor back to the zero position and then request it to move to 68,5 deg East and this is a well known one in SA. I also use this long travel so that I can monitor the spectrum as it moves.
Click to expand...

This bit I find slightly confusing (I now have the dish pointed at north), is that due North or actual North?

The procedure is, set USALS coordinates in your receiver, make sure the motor is zeroed (send to reference), then send the motor to 36E. At this point you need to go to the dish and motor and manually move the whole lot on the mast and play with the dish elevation until you locate 36E. Once found you should be on the arc, 68E is less than 40 degrees off centre, so shouldn't be difficult to pull in.

The above method is extremely reliable.

One point though, which LNB are you using, does it have an offset skew scale?
 
Hi rolfw,

I used a compass to do the pointing to North, so I would take it that it is True North not magnetic. I did notice that if the compass is too close to the dish it deviates a bit as well.

I will follow the USALS procedure once again as per your suggestion. I know for sure that the motor is zeroed but can always hook up the meter and request it to move to zero (i saved the Zero point as a position on my meter). I also used dishpointer to look at the North position for the HH90 and printed out the picture so that i could use it when on the roof as a guidline of where north is. I then fine tuned using the compass.

The lnb I have is a dual type, universal. It has a scale of some sort on the top, I would say the arrow would be the "zero" position and then there are little markings on either side of the arrow, so I guess these are the for the skew adjustments. I left the LNB at the arrow marking as as per info received before the skew will be done when the dish is moved via the motor. I will however fine tune once I get this working correctly.

One question though, what importance is the declination angle of 4,4 deg. in setting up the motor. Do I have to compensate for this anywhere. I think it's got to do something with the dish elevation or the motor latitude, but am not too sure.

Once again, thanks for the assistance.
 
The bearing indicated by a compass is MAGNETIC.

Not that it really matters, as aligning on 36E with the motor sent there with USALS will line the motor body up with TRUE north anyway.

The declination angle is taken care of when you adjust the tilt of the dish with its own az adjustment to get a lock on 36E.

Tilting the motor up/down adjusts the inclination, which is directly related to your latitude.
 
Hi Robbo,

Okay, just so that I am not confused. I line the motor up with the compass and i am now on Magnetic North. I move the motor via USALS to 36E. I then make any fine adjustments if required to ensure optimum signal strength. If I was at magnetic North to start with, then I should be fine. I did however notice that there is about 18deg difference between the Azimuth True and Azimuth Mag. Will this not play a significant role in pointing the dish to the correct North, ie. Magnetic or True ?
 
You need to forget all about magnetic North for a moment. The satellite positions are not easily related to it, but they are to true bearings. Pointing at the right satellite and getting a signal from it, will get you where you want.

The method I use, (which works is 99% of cases) is too look on dishpointer, zoom in, find a landmark (tree, building, river, road... whatever) and point the dish in that general direction to start with, and adjust from there. (Once sent to Nearest due north via USALS--36E for you).

As you say, if you line the motor up with a compass on MAG North,to start, you'll be about 18 degrees out. But send the motor to 36E, and swivel the motor round the pole eastward (I think, getting confused as its all upside down now) till you find 36E,it'l end up in the right place.
 
Just to add further info....I have 90HH Stab Motor and I am using the Usal system.....my location is Malta (just under Sicily) and I can pan from 45 W to 72 E with the Motor....Now when I installed it, I faced my Dish due South (Magnetic) and swiveled my Motor a little bit Eastward (but you could see that the Motor is turned quite Eastward when you look from the top of the Pole) so that I could find my True South..had to fiddle a little bit around until I could find the correct position of the Motor on my Pole so as to follow the Arc correctly. Now I am not quite sure in your case whether you have to swivel the Motor Eastward or Westward being in South Africa. But once you have sorted this out I am sure you will be alright.
 
Hi all,

I finally have some positive results....followed all the advice and and treated this like a 'new' installation. Got the North pointing sorted, got the motor to move to 36E via USALS on the receiver. THe dish moved to the requested position, I then made minor adjustments to the entire assembly, ie. Left / Right position. I then had to alter the dish inclination from the 41 Deg as per dishpointer to about 43 Deg. When the dish is requested to move to any other positions, I noticed that whilst the dish is moving I can see the other sats as it passes, but when I stop it at, eg. 45 East, the signal is not visible. I then played with the dish a bit and found the correct settings. So, now all this bit is sorted and guess what.....I found another problem.

My setup is as follows:

STB Unit hooked up to a 4 input Diseqc switch. At present, the C-band lnb is on port 2 and the KU band lnb on port 1. When the receiver is set as follows:

LNB1 Antenna Type: Fixed, all channels on C-Band set to port 2 and KU Band channels set to Port1 on the STB in the setup menu, Everything works fine (treating both dishes as fixed setups.)

As soon as I switch settings from Fixed Antenna to Motor Antenna, the system goes crazy. It will allow the KU dish to move and will display the channels correctly, but the hiccup is that I now cannot see any of the C-Band channels (no signal). It seems that the moment I use 'Motor Antenna', all signals coming in are from the KU lnb and the C-band signals are disabled.

Has anyone had a similar experience ?
 
Yes, go through the motor first and then to the switch and LNBs.
 
Hi Robbo,

Thanks for the speedy response. I'm a bit confused by your reply. Can you elaborate a little...
 
Receiver >>> motor >>> switch >>> LNb.
 
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