Focus dish problem

[alexpapi]

I bought a focus dish and I tried to set it up but I have signal but no quality.
I tried to catch echostar 7, but for some reason I have only signal and no quality.

First of all I want to know how can I calculate the angle for a focus dish on echostar 7.

I lives in Aruba, near the coast of Venezuela. I have a 6 foot satellite focus dish and the LNB I'm using is a Eagle Aspen DTV 32+.

Can someone help with my dish ,specially to find the angle I'm looking for.

Thanks

 

[gillham]

I lives in Aruba, near the coast of Venezuela. I have a 6 foot satellite focus dish and the LNB I'm using is a Eagle Aspen DTV 32+.

Can someone help with my dish ,specially to find the angle I'm looking for.

dishpointer gives me the following for Aruba to 119W
Ele: 32.5
Azt: 259.3 (true)
Azm: 269.2 (magnetic)

 

[alexpapi]

Elevation angle and azimuth for Aruba

Thank you for this information. According to the other information I received this is the same elevation angle for a offset dish. The azimuth must be the same.

Can you tell me if the Eagle Aspen LNB DTV 32+ will function with my prime focus dish?

Thanks

 

[gillham]

Thank you for this information. According to the other information I received this is the same elevation angle for a offset dish. The azimuth must be the same.

The scale on the offset dish already subtracts the dish's offset. The elevation of the satellite is used directly on the BUD since it is pointed directly at it.

Can you tell me if the Eagle Aspen LNB DTV 32+ will function with my prime focus dish?

Thanks

I can't, hopefully someone else here can. I've seen photos with modern Ku LNBFs hooked up as you suggest. The link below is to a bracket that Sadoun sells. Since it is for LNBFs with a 40MM throat, I am assuming an offset dish Ku LNBF would work, but I don't know.
C Ku Prime Focus Dishes LNBF Holder

Also dishpointer says you're outside the footprint for 119° on Aruba. You might want to find a bird that dishpointer.com thinks you should be able to get. Use that to fine tune your mount and LNBF setup. Then keep moving west until you get some NASA TV.

 

[SatPhreak]

A lnb designed for an offset dish won't work very well on a prime focus dish. It will work if you are in a high signal area of the sat beam, but since you are out of the foot print it probablely won't. It would be best to get a lnb designed for a prime focus dish.

 

[Anole]

ideas

Can you tell me if the Eagle Aspen LNB DTV 32+ will function with my prime focus dish?

That LNB is designed for an offset feed dish, not a prime focus dish, so it won't be very efficient (as described above).
Though not listed in the specs, I would say the LNB was designed for a dish with an F/D in the range of 0.6 to 0.7
Your prime focus dish is more likely has an F/D of 0.28 to 0.42
What that means, is that your 6' dish might perform no better than a 3' dish.

I wonder if you can use bandstacked LNBs in your setup?
In Dish-language, it would be called: DishPro
The Eagle Aspen LNB you have selected is what's called Legacy style, which uses 13/18 volts to select Right or Left circular polarization.
In the United States, I would use a surplus Dish Network bandstacked LNB from a SuperDish, attached to this Invacom AF-120 feedhorn.
It is a combination which would match your prime feed dish much better.

edit:
And though a little more expensive, you could also use the Invacom QPF-031 (Legacy) LNB with that feedhorn.
That would be functionally closer in design to using your Eagle, but with better gain, matching, etc.
(it would be a direct drop-in replacement)

So, I guess that's two solutions...

 

[alexpapi]

Thank you very much guys for the tips. I just bought a INVACOM QPF-031LNB from a friend of mine. I will test this later in the week since we are experiencing some bad weather in Aruba.

Another important question: Most people in Aruba are using Off set dishes and they catching signal from echostar 7 without any problem. Do you think there is something special with these dishes compare to my prime focus? according to me, we are in the footprints of 119.

Do you think I will need a satellite finder meter and if I do which one do you recommend. (at the moment I can borrow the simple one from a friend)

Thank you.

 

[SatPhreak]

You should be OK with the qpf lnb as long as you have the matching ADF-120 feed horn to go along with it. That feed horn is designed to work on a prime focus dish. As long as other people in your area can receive signal on a 6'dish (offset or prime focus) you should not have a problem with a 6' prime focus with the ADF-120 and QPF-013.

I would love to go to Aruba BTW. Winter is setting fast in the great white north. BRRR.

You can borrow the sat meter, but I have always used a receiver with a tv that I can see. Either way it's better than yelling "what's the quality" over and over.

 

[alexpapi]

Thank you sathphreak. You are welcome in Aruba. We have a sunny weather everyday. Come and enjoy our beaches........

So you are telling me that I will need a ADF-120 to work along with my qpf-013. because i will order one right away. The only thing I bought was the LNBF collar bracket II.

I will try out this weekend. Anything else I will post.

Thank you.

 

[SatPhreak]

Yes you will need the adf-120 to go with the qpf, as the qpf is a lnb only and has no feedhorn or scaler ring. The adf-120 is just the feedhorn and scaler. I don't know if the adf-120 requires the bracket or if if bolts directly on to the dish's feed arms, as I've never had one and the PDP file from Invacom doesn't say.

 

[SatPhreak]

I've tried a circular DTV lnb on a 10 foot dish about 7 years ago and it worked, but had slightly less quality reading than I got on a 24" dish. That's why it's important to match the dish with the correct lnb/feedhorn when in a fringe reception area.

 

[alexpapi]

Do you know where I can see a clear picture of the ADF-120 feedhorn, because I can not imagine how this big LNB(QPF) will fir throught a small feedhorn.

Maybe I will have to see it in a diffrent way.

Do you think I f I just put the LNB on the scaller ring bracket it will work?

 

[Anole]

The link I gave above in post #6, will show you pictures of the LNB and the feedhorn.
Also, you can go to Invacom web site. They have PDF documents for all their products.

Yes, you'd likely need an adapter bracket to mount the Invacom+feedhorn on your BUD.

Somewhere on the forum, one of the users has a picture where he shows the ADF120 feedhorn mounted in the center of a regular BUD scalar.
I guess the sizes are about right, and it was the easy way to go.

edit: I found the pictures.
ACradio posted to his picture site.
You'll know 'em when you see 'em.

By the way, there are two models:
QPF-031 has a Flange for an external bolt-on feedhorn - you do want that one.
QPH-031 has a built-in feedHorn - you don't want that one.

 

[alexpapi]

Can you tell me what is the different between teh QPF-031 and the QPH-031. To me they look the same. one is double and the other one is quad. Please correct me if I'm wrong.

 

[Anole]

Both have four outputs: two circular, and two linear, clearly marked.
They differ only in that one has a built-in feedhorn, and the other accepts bolt-on feedhorns.
See picture on PDF datasheet at the Invacom web site.

The model with the build-in feedhorn is intended for use with offset dishes.
Those have an F/D ratio of 0.6 to 0.7, so the LNB is matched to the readily available offset dishes you find.

For use on a prime-focus dish, all of which have F/D in the range of 0.3 to 0.4, you need a suitable feedhorn.
This is so the LNB can get signal from the entire dish surface, not just the part in the middle.
Invacom sells the ADF-120 feedhorn just for this job.

The pictures on the ACradio site I linked above, shows an ADF-120 and Invacom LNB, mounted in the middle of a BUD scalar ring on a 6 or 8 foot dish.
His rear-view picture shows the mounting adapter bracket quite clearly.
You need to do basically the same.
(actually, it looks like ACradio used a slightly different model LNB, but the idea is the same)

 

[alexpapi]

Hey this is great.! thank you for this tip. I'm feeling that I'm getting through this now. so I think I have the wrong LNB (QPH-031) I will order the correct one by tomorrow. (QPF-031) plus the ADF-120 feedhorn.

I will keep you guys uptodate. anything else I will post.

thanks a lot for the help.

 

[alexpapi]

Can someone tell me what is the distance from the point of the Feedhorn (LNB) to the center of the dish.?

 

[Lak7]

This should help.....
Tune Up Of Your Satellite

 

[alexpapi]

What if my dish do not appear on the list. I have a Fortecstar Prime Focus dish 6".
Is there any other side where I can check how to calculate this.

Thank you

 

[Anole]

or just look it up

Focus Length 682 mm (26.85")