LNB/feedhorn Skew

[emuman100]

Hello,

I got myself a 240cm Fortec Star dish, ground mount. I also got a Chararral Dual output C band feedhorn and 2 Norsat 8515 LNBs. It's stationary and I just want reception of AMC11. I got the Dish level as best I could, it's fairly level on it's platform. I set azimuth with a compass and elevation with a school protractor, piece of twine through the protractor's hole and a weight on the other end of the twine. I'm assuming that 0 degrees of elevation would be the reflector perpendicular to the ground? With this assumption I adjusted the elevation to 17 degrees as best I could. (Dish has no elevation scale)

Now, with that correct, and a Dual output feedhorn, how do I skew the feedhorn to give me a starting point so I could easily find a signal? The calculators I've used say that for my location I should skew it at 43 degrees, but none of them say cw or ccw. I do know to verify focal depth and the f/D ratio on the scalar ring.

With my 180cm Fortec, I found a signal easy because I first searched for Ku signals with a KU LNBF I had. With azimuth and elevation set I could peak the C band feedhorn skew. If the skew on the feedhorn was not right, I would get no signal at all. I also was using a dual output Chaparral feedhorn. I knew where to point the dish prior because I seached for Ku first, because if I did not do that, I would get no signal at all.

With my 240cm Fortec, AMC11 is C band only, and it's bigger and could collect more signal, but where do I adjust the feedhorn skew to to give me a starting point to get my azimuth and elevation set right? And since I have a cheap analog signal finder and a DVB FTA receiver, how can I align it with mostly DigicipherII signals?

Thanks so much.

Jonathan

 

[gabshere]

Jonathan
using the DVB receiver and lyngsat there is a dvb signal to tune with on AMC11
so pick that transponder freq and tune to it.

i think its ccw

where you at by the way my skew for that sat is also 43

 

[emuman100]

gabshere,

Thanks for the reply. I'm in Pennsylvania. Right now the only DVB on AMC11 is the QVC transponder and the few powervu transponders. I guess I can use them too? And if it's ccw, is that looking into the feedhorn or looking at the back of it? Once I set the skew, f/D ratio, and focal distance, I should be ready to find a signal?

Thanks.

Jonathan

 

[gabshere]

yes looking at the lnb from the front of the dish

 

[emuman100]

So I'd be looking at the back of the LNB, and the front of the dish. Is the skew ccw from the vertical antenna being straight up?

Thanks.

Jonathan

 

[WyrTwister]

Hello,

I got myself a 240cm Fortec Star dish, ground mount. I also got a Chararral Dual output C band feedhorn and 2 Norsat 8515 LNBs. It's stationary and I just want reception of AMC11. I got the Dish level as best I could, it's fairly level on it's platform. I set azimuth with a compass and elevation with a school protractor, piece of twine through the protractor's hole and a weight on the other end of the twine. I'm assuming that 0 degrees of elevation would be the reflector perpendicular to the ground? With this assumption I adjusted the elevation to 17 degrees as best I could. (Dish has no elevation scale)

Now, with that correct, and a Dual output feedhorn, how do I skew the feedhorn to give me a starting point so I could easily find a signal? The calculators I've used say that for my location I should skew it at 43 degrees, but none of them say cw or ccw. I do know to verify focal depth and the f/D ratio on the scalar ring.

With my 180cm Fortec, I found a signal easy because I first searched for Ku signals with a KU LNBF I had. With azimuth and elevation set I could peak the C band feedhorn skew. If the skew on the feedhorn was not right, I would get no signal at all. I also was using a dual output Chaparral feedhorn. I knew where to point the dish prior because I seached for Ku first, because if I did not do that, I would get no signal at all.

With my 240cm Fortec, AMC11 is C band only, and it's bigger and could collect more signal, but where do I adjust the feedhorn skew to to give me a starting point to get my azimuth and elevation set right? And since I have a cheap analog signal finder and a DVB FTA receiver, how can I align it with mostly DigicipherII signals?

Thanks so much.

Jonathan

43 degrees is pretty close to 45 degrees , which you can probably approximate by eyeball . Once you get a signal , you can tweak the skew .

If you do not get it on one LNB , power down the receiver , switch to the other LNB , power up the receiver & try again .

Or just blind scan . There are a few free channels on both V & H transponders .

Check out

AMC 11 at 131.0°W - LyngSat


As far as the dish angle , look up both angles , for your location . Since you are using a fixed dish add them up and use the sum .

Go down to Harbor Freight and buy an angle finder ( inclinometer ) for $ 5 - $ 10 .

With both skew and elevation approximated , set up the DVB receiver & a TV by the dish and either use a signal meter ( cheap on EBay ) or the signal meter function on the DVB receiver , to tweak the azimuth .

Then tweak everything else .

Since you are using 2 LNB's , are you going to use a Disque (sp) switch at the dish ?

Wyr

 

[emuman100]

WyrTwister,

The dish angle you mean azimuth and elevation? Add them both up?

I'll be connecting both LNBs to a satellite splitter, and connecting a couple commercial IRDs to each polarity so I can QAM modulate the multiplexes over my private CATV system.

I have the protractor, and found the elevation that way. I'll do it the same way with the LNB skew. I'll have an inclinometer in a day or two to double check. I left it at work. With this information I think I know how to do this.

Thanks so much.

Jonathan

 

[emuman100]

I'm still having no luck. I managed to pick up QVC analog very snowy, but that's on AMC10. This $10 signal meter just won't cut it. I can get AMC10 it seems and get something a few degrees east but I just cannot lock onto AMC11.

Can someone verify the QVC transponder on AMC11 as tp 11, 3928MHz, 14323 symbole rate and an FEC of 5/6? the LNB skew is actually cw according to dish poiunter. I had it set ccw, possibly that is myt problem.

I'm using my compass in the back of the dish, but I just can't get it to to point properly. Is it because I'm using it in back of a steel dish?

And should I invest in a decent signal meter?

Thanks.

Jonathan

 

[Lak7]

When using a "Cheap" meter, try keeping it behind the dish for a better reading.
For skew (when behind the LNB and looking at the face of the Dish, your back to the sky) If the Sat is on your Left, then the LNB skew is to the Left - CCW
This page may help.....
Satellite Look Angles Satellite Heading Calculator Azimuth Elevation Skew Tilt LNBF Latitude and Longitude values

 

[emuman100]

Thanks guys so much. Apparently I never noticed before that dishpointer said the LNB skew was cw. Once I set it I got QVC digital and HD at 60%. C-SPAN analog comes in pretty good too.

Can you guys verify that Discovery HD Theater is not FTA? I can't get it to authorize on my commercial DCII receiver. I thought it was FTA.

Thanks.

Jonathan

 

[truckracer]

Discovery HD theatre is encrypted DCII. You would have to be subbed with a dsr-905, 922 with a HDD-200 decoder box.

Good job with your install. You will enjoy the world of FTA.

 

[emuman100]

Thanks again guys.