More Problems...

[revx]

So i took everybody's advice and instead of installing on my wall, I did a temporary install on my south facing fence. Just to make sure my angles where set correctly... again this isn't the first dish I've installed, but it is the biggest and it's turning out to be the hardest. (never done a motor before).

So, I took a bunch of pictures instead of typing a long story; but to summarize, I think either my dish angle or my motor angle is 'off'.

Here's a picture of it pointed at 148W... almost looks like it's pointed at the ground...

Here's a picture of it pointed at 119...

and a picture of my Dish500 at 119 & 110 for reference:

The picture of 61W lookes similar to 148, but pointing at the ground on the other side.

[revx]

(too many pictures for single post...)
My settings are as follows:
North Latitude: 33.1
West Longitude: 96.7
Dish Elevation: 24.61 (not this ajustment seems a little lose; even though the bolts are tight)


Motor Elevation: 33.13

Did I do something wrong?? The whole thing seems like it should be pointed higher in the sky...

Also, I'm not sure (but I am sure it matters) how to tell if the dish is mounted on the motor pole right. Seems like it may be off a bit?


And one last question... where in the LNB holder should the LNB be?

Seems like it can move in and out quite a bit and again that probably matters...

Thanks again!
reVx

[wejones]

Seems like if your latitude is 31.1 then your motor elevation should be something like 58.3 . Where did you come up with the 33.13?

[revx]

I used this site:
http://satcalculator.freehostia.com/
put in my LAT & LON and SG2100 motor...

Where did you get 58.3?

[lostinthewoods]

Hi,
If I am looking at the pictures, it appears you have used the wrong scale on the motor. The pictures show you have set the motor elevation to your latitude! Look on the other side of the motor and you should see a scale for latitude!

Also looking at the mount of the dish on the motor, it would appear that you have not aligned the dish with properly with the necessary 0 refrence.

As for the exact location of the lnb in the mount, worry about and peak that when you get the dish alignment setup properly.

You are located a little north of me, but my dish does not point at the ground!

Lost

[pmb1010]

The scale on the side of the motor you used would be around 57, based on the table in the sg2100 manual:

http://www.dmsiusa.com/documents/Man...100%20New1.pdf

[wejones]

Originally Posted by revx

I used this site:
http://satcalculator.freehostia.com/
put in my LAT & LON and SG2100 motor...

Where did you get 58.3?

90-(31.1+.6)

[revx]

Originally Posted by pmb1010

The scale on the side of the motor you used would be around 57, based on the table in the sg2100 manual:

http://www.dmsiusa.com/documents/Man...100%20New1.pdf

Thank you. That is better than the 'handout' that came with it...

this is a picture of the other side of the motor; the Latitude scale, and it is indeed at about 57.

Originally Posted by lostinthewoods

Also looking at the mount of the dish on the motor, it would appear that you have not aligned the dish with properly with the necessary 0 refrence.

That was one of my concerns... where are the alighnment marks?

I'm going to read throught the manual and check things over again...
thx!
reVx

[ahoss2000]

I have a Stab HH90 motor, and it took me 4 hours on my temp. setup before I got a lock on my South Sat. Then it took me another 3 hours when I mounted on its permanant pole, during which I was sure something has failed in my system until finally I got a lock.

I was also off 6-7 degrees from calculated dish elevation angle, supposed to be 41, ended up being 34.

So it is very important that you spend enough time at every angle on your dish elevation while going east and west 5-10 degrees. Also, pick a strong Tp to work with on your S. South. The person that said he is above you, can tell you what is a strong Tp on your S. South. Program that in your receiver, and go at it again. You can see my temp. set , I sat on chair behind the dish and worked on it until signal showed up. It is so touchy at first, but once you do it once or twice, it is not that hard.

[revx]

Originally Posted by ahoss2000

... Also, pick a strong Tp to work with on your S. South. The person that said he is above you, can tell you what is a strong Tp on your S. South. Program that in your receiver, and go at it again...

My 'south satellite' is the Intelsat Americas 5 @ 97W... can anybody recommend a good TP? Looks like TP5 (11836) has a lot of free stuff on it.

After reviewing the install manual; looking at a bunch more pictures, I'm still confused and concerned why it apprears to be pointing down. The install manual from DMS's website says sat elevation should be 40 - declanation... everything else I've read (including the install guides on this site) say 30 deg. Guess I'll just have to play with it. But any other ideas will be appreciated.
TIA
reVx

[boroda1]

Originally Posted by revx

And one last question... where in the LNB holder should the LNB be?

Seems like it can move in and out quite a bit and again that probably matters...
reVx

Usually, it's recommeneded to pull it out from dish as far as the black ring allows

[pmb1010]

Regarding the motor setting:

if you use the "latitude" side, put it at your real latitude.
If you use the "elevation" side, put it at the table calculation from the manual.

I think you have things reversed 100%.

There are 2 calcuations you need to make when using a motor.
One is the motor bracket, the other is the dish elevation. Dont confuse the 2.

Once you get the the motor bracket set correctly and the dish elevation, things should fall into place.

[wejones]

Originally Posted by pmb1010

Regarding the motor setting:

if you use the "latitude" side, put it at your real latitude.
If you use the "elevation" side, put it at the table calculation from the manual.

....

{Broken record mode on}

First I want to correct what I said above when I said:

"Seems like if your latitude is 31.1 then your motor elevation should be something like 58.3 ."

And then I explained the above by saying:

" 90-(31.1+.6) "

Perhaps it is obvious, but I somehow mis-read the latitude as being 31.1 instead of 33.1. So my calculation above for the elevations should have been 90-(33.1+0.6) = 56.3 . Ie I would recommend using an elevation of 56.3, which is the same thing as using a latitude setting of 33.7, rather than using your actual latitude as the motor angle. I have an explanation of this on my own web page, however the best web page out there for understanding dish alignment is http://www.geo-orbit.org/sizepgs/tuningp2.html

and one of the links on this page is:

http://www.geo-orbit.org/sizepgs/decchartp.html

which is a pretty nice discussion of declination.

To keep a long story slightly less long, the problem is that the declination of satellites to your south is greater than the declination of sats to your east or west. This difference is in the range of 0.6 or more if you are up north, and 0.5-0.6 if you are down soutn. Basically, there are two ways of aligning a polar mount.

The first way of aligning a mount is to set your motor inclination to 90-latitude, ie use your actual latitude. If you do this, you have the choice of using the declination of a southern sat, which will mean that your eastern and western sats will be out of alignment by up to 0.6 degrees, or you can pick some declination in between, so that your southern, eastern and western sats will be out by 0.3, and the southeast and southwest will be right on. Both of these are approximations, but approximations which are good enough for small KU dishes or large C-band dishes (but not large KU diahes).

However, the second and better way of aligning a polar mount, is to use the declination of a far east or far west satellite. This is what is indicated by the "Modified Polar Mount Tracking Angles" at the above URL. You will notice that the declination angles in this chart are about 0.5 to more than 0.6 degrees LESS than the declination angles that you'd find on the Sadoun site or on the first chart at the URL above.
Now, if you use the modified declination numbers, it is necessary to change the motor inclination by that same 0.6 degrees. This means using a latitude setting 0.6 degrees greater than your actual latitude. The motor inclination has almost no effect on sats to your east or west, because that rotation angle is orthogonal to that direction, so in effect declination will be proportioned across the arc, and you will be accurate to a few hundredths of a degree across the arc.

[ahoss2000]

I agree with pmb1010. Use the latitude side of the motor bracket, and set it to your latitude of 33, this would lift up your dish. Next set the dish elevation :

• Now, adjust the dish elevation angle (Pictures 6 & 7) to peak the signal.Dish elevation angle is calculated based on the model of the HH motor you are using, as follows:

Motor ModelDish Elevation CalculationsSatcontrol SM3D12Equals = (46.5 minus declination angle)STAB Motors (HH100 & HH120)

Click here to calculate

STAB Motors (HH90)

Click here to calculate

Pansat PM900 SEquals = (46.5 minus declination angle)Moteck SG2100Equals = (30 minus declination angle)

Declination angle chart is provided HERE!

[revx]

SUCCESS!!

Thanks to everybody that chimed in... but mostly to pmb1010 to who hit the nail on the head. Also big thanks to WesJones for the great links.

So my motor braket was 100% wrong... moved it to the right place (Lat @ 33) fine tuned the elevation of the dish (it was at 24; now ~21) and BOOM there was Intelsat 5! I scanned a couple TP's and it looked good.

I'm now satisfied that I'll be able to get it up where it belongs with not to many problems. I'm hoping the weather cools down a bit (at least below the century mark - currently it's 106) and I'll tackle this next weekend.

Thanks again!!
reVx