Mounting two LNB's on one C-Band dish question

[Richinald]

Hello,

I am working on a satellite project and was curious to know if Eutelsat 113WA and Eutelsat 117WA (formerly known as Satmex 6 and 8) can be received together on one mesh C-Band dish using the correct Lnb's and fitting adapters.

Since the spacing between these two TP's looks to be very small in this case Eutelsat 113WA located at 113.0 W and Eutelsat 117WA located at 116.8 W.
I think it should be possible for mounting two LNB's on one dish, but would like to check if this would be technically possible on a mesh C-Band dish or if someone has done this with their C-Band dish and what brand of LNB and adapters would work well for mounting two LNB's on one C-Band mesh dish.

Thanks in advance for the help.

 

[FaT Air]

Been done many times by members, but not this one. May have to cut the scalars to get them close enough. Here's 2° shown here: http://www.satelliteguys.us/xen/posts/3655968/
Only example I could find using the search, but know there are more examples)
Dimensions, FL of your dish determines the 'closeness' of your feeds.

 

[Jason S]

There are photos of some pretty neat mounts fabricated for multi-LNB and LNBFs in Post # 269, found here:
http://www.satelliteguys.us/xen/threads/pics-of-the-dish-farm-post-yours-too.131140/page-11

 

[fred555]

I am in the process of adding more LNBFs to my 10 footer.

Here is the mount for the 4 degree separated one:

Whoops, that is the fresh caught Marlin Steak I just had for dinner, here is the bracket:

So right now I have 101W in the center and 105W to the right.

Used 3/4 inch electrical conduit hangers and some aluminum bar stock.
I did like Ke4est said and moved the lnbf around by hand until I got a signal.
Then cut, bent and drilled the aluminum supports to place the scalar in roughly the right spot.
Then put the lnbf in the scalar and adjusted for max signal. That was over a month ago.

I was getting NASA over 70% with this setup and wanted to try for COZI which I was not getting even a hint of a signal from.
I took the picture today during disassembly because I moved the right scalar closer to the center lnbf.
I used a dremel to cut semicircles in both scalars in order to move them closer by maybe 3/4''. The right side scalar as you can see goes below the center one. COZI is coming in now too as well as the NBC feeds on 105W.

It got too dark to take the finished picture with the new position and modified scalars, but I will try to do that tomorrow night.
I had an lnbf in the same spot at 2 degree separation but I did not like any of the channels
and wanted to get 105W on that side to get NASA.

This weekend and am going to put a third lnbf on the left side for 99W, 2 degree separation.
Instead of using the scalar I already have cut for 2 degrees, I'm just going to dremel the existing scalar in place like I did
for the right side one tonight. I don't want to disassemble the center scalar, cut it, reassemble, have to readjust it for Q, readjust the right side one, then fiddle with the new one. It is very time consuming.

So if you are going to try for multiple lnbfs on C band, some tips:
Be patient.
Get a dremel tool if you are going to try for 4 degrees or less.
Go here and get many extra scalars too, because your going to cut them up and make mistakes:
http://www.titaniumsatellite.com/pr...-Prime-Focus-Dish/p/39948004/category=6743545

I will try to post some pictures tomorrow night and more this weekend. I want to hurry to get this project finished with 3 lnbfs
and move on because I have a 6 footer, 8 footer and a Ku dish to plant in new spots.

 

[migold]

My avatar shows LNBFs on an 8 ft dish with 6 deg spacing to get 99W and 105W. I have LNBFs on my 10 ft mesh working with 4 deg spacing to get 97W and 101W. Avatar picture is old, now I am mounting the second LNBF with 2" conduit hangers bolted together off the prime focus LNBF. It is working good for me.

 

[fred555]

My avatar shows LNBFs on an 8 ft dish with 6 deg spacing to get 99W and 105W. I have LNBFs on my 10 ft mesh working with 4 deg spacing to get 97W and 101W. Avatar picture is old, now I am mounting the second LNBF with 2" conduit hangers bolted together off the prime focus LNBF. It is working good for me.

Can you post a bigger version of your Avatar picture. My vision is pretty bad.
I like seeing various mounting ideas.

 

[Vallenato]

On these projects Multifeed C band
What is the number of degrees between 2 LNB C Band with the scalar put together..
I know that 2 Lnb KU are about 9 degrees. But I would to know about C band with scalar
thanks

 

[FaT Air]

The F/D ratio, and the Focal length basically 'sets' what the minimum sseparation would be. So, I think, only experimentation will find out what your's will be.
Think most have found 4° separation, as a minimum, with the scalars either drilled or cut to place the LNBF throats close together.

 

[lost_mesa]

On my 10 foot dish I have 2 C Band feeds side by side. Probably about a 1/2 inch space between the scalars. The two beams are a tad over 6 degrees apart.

I wasn't trying to achieve any particular satellite spacing between the two feeds. The prime focus feed is for linear polarization and the offset feed is for circular.

You can easily do less than 9 degrees with Ku LNBs side by side.

 

[migold]

Here are photos of 2 examples:

Photo of my 10 ft mesh buttonhook dish with 2 LNBF, prime for 101W and offset for 97W - 4 degree spacing.

Closeup of the mounting

Closeup of the mounting from opposite side

I'm using 2" pipe clamp, bolted back-to-back, and sprung to fit the LNBF diameter, and clamped with longer 1/4" bolts.

Below are the 2 LNBF mounted on my 8 ft solid dish, prime for 99W and offset for 105W - 6 degree separation. I am using the same mounting hardware, with a longer bolt between the 2 clamps to space the offset further away from the prime.

In both cases, I am getting good quality signals from the offset LNBF. I used the 105W offset for several years to feed my 4DTV receiver with good signal quality, until they took Starz off and I ended my subscription.

 

[danristheman]

Here is my setup I am about 10 degrees off center mini bud.

 

[MN_Vikings]

I have been having moderate success with 5 LNB's on my C-Band Dish. I am however confused about how to set up and maximize the Disque 1.0 and Disque 1.1 settings on my receiver and In the photo's I'm using 2 Zinwell 6X8. I have since added 2 more 6X8 Zinwell Multi-Switches so I now have a total of 4 Zinwell 6X8 Multi-Switches (Only using ports 1-4) and four Disque switches to hook up a total of four receivers but not made it that far yet. I think I will create a new thread bout the Disque 1.0/1.1 receiver settings but here are some photos of my setup. I have since ordered a 17X1 powered multi-switch off ebay so hopefully it will be easier to set up and configure with the receiver..

 

[FTA4PA]

I have been having moderate success with 5 LNB's on my C-Band Dish. I am however confused about how to set up and maximize the Disque 1.0 and Disque 1.1 settings on my receiver and In the photo's I'm using 2 Zinwell 6X8. I have since added 2 more 6X8 Zinwell Multi-Switches so I now have a total of 4 Zinwell 6X8 Multi-Switches (Only using ports 1-4) and four Disque switches to hook up a total of four receivers but not made it that far yet. I think I will create a new thread bout the Disque 1.0/1.1 receiver settings but here are some photos of my setup. I have since ordered a 17X1 powered multi-switch off ebay so hopefully it will be easier to set up and configure with the receiver..

Nice setup! Which sats are you getting with it?

 

[fred555]

MN_Vikings, nice setup!

If you have any questions about the diagram below feel free to ask.
Its what I'm running. I chose the 4x8's for simplicity. It uses Diseqc to choose multiswitch then 22khz to choose lnb on that multiswitch.
It will scale up to or a combination of 8 receivers (by adding one more multiswitch) and 8 sats.

I like it because it gives instant channel changes between sats and I cannot motorize due to trees.
Each dish peeks out through a clearing.

 

[richyrich]

I seem to be missing the formula distance, can someone please help. I need to know the formula using f/d ratio. I know diameter of my dish is 102", depth is 15.25". what would my focal distance be. what is the formula

 

[MN_Vikings]

Nice setup! Which sats are you getting with it?

I have been able to get reception from up to 3 satellites that are close together for example 91-93-95 or 99-101-103. I have just re-configured my LNB's so I have to re-aim and fine tune. After I get my final LNB and new powered multi-Switch installed the plan is to unplug all LNB's except the one mounted in the middle scaler ring. I tried to set up the DiESec 1.2 actuator motor and vbox with all the LNB's connected and could not get centered on any one satellite without getting feeds/interference from other satellites. After I have my DiESec 1.2 and vbox set up and aimed correctly at each satellite I will then hook up the other LNB's to hopefully get multiple feeds from the next satellites on the arc.

 

[MN_Vikings]

MN_Vikings, nice setup!

If you have any questions about the diagram below feel free to ask.
Its what I'm running. I chose the 4x8's for simplicity. It uses Diseqc to choose multiswitch then 22khz to choose lnb on that multiswitch.
It will scale up to or a combination of 8 receivers (by adding one more multiswitch) and 8 sats.

I like it because it gives instant channel changes between sats and I cannot motorize due to trees.
Each dish peeks out through a clearing.
View attachment 107416

Fred, thanks for the offer and I will take you up on this.. I have quite a few questions so why don't I start a new thread instead of hijacking this guys thread...