Building a 1.2 meter dish with 2° Spacing

[Wescopc]

I made a dual LNBF set for receiving 123W (G18) and 125W (AMC21) using the mini LNBFs from SatelliteAV (-SINGLE STD FTA SATELLITE LNBF- MINI - SatelliteAV, LLC.) and the GeoSatPro 1.2 meter dish from SatelliteAV (GEOSATPRO 1.2M OFFSET SATELLITE DISH - SatelliteAV, LLC.).

The Center Line spacing of these mini LNBFs is 40mm as they come out of the box. I wanted 30mm C.L. spacing. So I machined 5mm off of the adjoining sides of the LNBFs and mated them with silicon RTV rubber & a tie wrap.

Next I fabricated a mount from a 3/8 inch pipe nipple bent to 45°. I then fastened the dual LNBFs to the mount with a hose clamp. This allowed the paired LNBFs to be skewed. Here in Oregon I only needed 1° because my longitude is 123°, but the set up can be skewed on the pipe nipple as needed.

I have attached pictures of the process and the finished setup.

I receive both satellites just great.
Bob

 

[Mr Tony]

very cool

What kind of signal quality you getting on both?

 

[Wescopc]

~60-65% on a Merc II. Will get better numbers when I get it permanently mounted to the house.
Bob

 

[empiretc]

how much??

 

[Wescopc]

how much??

for what?

 

[skysurfer]

pretty cool to see the inside of LNBFs. I always thought they were circuit boards and such epoxied to the inside of the case. I didn't realize they were self-contained in a metal case and then the outside was put over that.

I may try a G18/AMC21 experiment using a thing I picked up many years ago. It's a curved bar with clamps - one LNB goes at the center and the bar has room for a few more LNBs if you want. I last used it for AMC5/SBS6/AMC6 setup but the bar has been void of all but the center LNB for a few years.

 

[FTABman0]

A+ for being very innovative! Very Cool!! :up

 

[Anole]

I guess taking 5 mm off the side of each Mini wasn't so difficult after all. -
You really made it look easy! - :up

That sort of puts to rest any questions about the guy on eBay selling such a similar concoction.
Maybe you should too.
I wonder if the "how much" question has to do with how much you want for a pair...?
I'm sure you can get those LNBs pretty cheaply, if you ordered up a few dozen!

But, see page 4 & 5 of the AMC 21 thread for calculations describing how the center-to-center spacing varies based on dish size and the user's location.

Very nice work! Thanks for sharing the pictures.

 

[Mr Tony]

but the 2 degree thing on fleabay is for a 90cm (supposedly) dish....OP used a 1.2m which has a farther focal distance than a 90cm dish

 

[tvropro]

I have 2 of those LNBF's and just for the heck of it yesterday I took my G-27 WSTV one off the clamp I made and tried to get 125 by waving it around the other one where it would need to be. I left the dish pointed at G-18. I tried 3 transponders for 125 and when I was right up against the mount for the G-18 LNBF I was starting to see signal increase but no quality. I figured I needed to get the lnbf's closer together to acomplish this. So I scrapped the idea since didn't feel like getting deep into mod's yesterday and PBS won't be MPEG-2 SD that much longer anyway (from what I heard) I returned the LNBF for WSTV viewing retuned and picked up some quality there. So doing something like wescopc did is needed since the birds are very close.

 

[empiretc]

for what?

to send me one, lol.

 

[Wescopc]

to send me one, lol.

I gave you the "blue prints" have fun!
Bob

 

[neftv]

That is pretty cool. Say is it possible to do this on a Channel Master 1.2m dish? The feedhorn mount is different than yours.
Then my second question is it possible to do this with Cband with two satellites 3 degrees appart?
I was just curious. I don't have a machine shop to do this.

 

[SatelliteAV]

Bob,

I knew that it would be just a matter of time before you would build a transformer with my creations! KUDOS!

 

[empiretc]

Brian, an plans on having something like this available?

 

[Anole]

empiretc -
Read the thread I linked in my post above.
The problem is, WHERE you are in the country has an affect on how far apart the LNBs need to be, and WHAT DISH you use, does as well.
There is no one-solution-fits-all.

neftv -
Get the focal length of that dish and your zip code and we'll see how far apart your LNBs need to be.
Might not need any grinding at all.

 

[Wescopc]

Update

I have now mounted the dish at the house. I added 129°W (G27) and 119°W (Echo 7) to the 123°/125° (G18/AMC21) co-joined mini-LNBs. Signal quality (Fortec Lifetime Ultra):
129 - 73%
125 - 85%
123 - 80%
119 - 99%

Pictures below, first pic of the new 1.2 meter followed by my T-90 and two dish network dishes. If a person wanted to have just one dish, the 1.2M dish with these four LNB's would give a very nice set of programs.
Bob

 

[voomvoom]

Good Job..!!! That's a nice looking dish, I like that Torodial too....

 

[Wescopc]

Good Job..!!! That's a nice looking dish, I like that Torodial too....

Figured you might like the T-90 - just a guess.

 

[Smith P.]

Your other three dishes pretty close to A/C - have you seen increasing noise or other anomaly with signals when A/C kicking on and running ?