Dispelling some urban myths regarding Multi LNB positioning

[Ghostleader]

Ask your average Sat enthusiast how to set up a multi LNB bracket on a typical size dish etc and they will tell you if it's for the usual three birds (13e,19e & 28e) then you should focus the main LNB on 19e & have 13e at one side & 28e at the other, which is sound thinking & works very well:-thumb1 . However my gripe is with these people who shoot down any other thinking/configuration in regards to LNB placement, if you suggest to your average serial poster/bullsh*ter that you were considering using 13e as your focal LNB & 19e & 28e as your offset's they will tell you it wont work unless your dish is a metre, it wont work at all, or at the very thought of rain 28e will break up like indoor aerial having a go at Freeview while someone in the room decides to test four hair dryers right next to it. Well to those in the know:-uzi, say hello to my little friend:

 

[Ghostleader]

I'd also like to take this opportunity to point out that no such ill informed rants have been bestowed upon me here, but lets just say that digitalspy is best avoided.

 

[Lazarus]

I'd also like to take this opportunity to point out that no such ill informed rants have been bestowed upon me here, but lets just say that digitalspy is best avoided.

Ah, another victim .................... :-Jumbo

 

[Rick]

Alot depends on the equipment as well. For example a TD78 or 88 with triax multi-block, dosen't allow a focal LNB at all. So for 13/19/28, the focus of the dish is best positioned between 28e and 19e.

 

[satelliteman]

No problem with a gemini 70cm either.

 

[hexah]

Or cheat with the Technisat Multytenne for 28-23.5-19-13e.

Point to 19e and no further fiddling is required.

Not to mention the Maximum T85 or the Wave Frontier T55 or T90.

 

[Ghostleader]

Or cheat with the Technisat Multytenne for 28-23.5-19-13e.

Point to 19e and no further fiddling is required

For middle England maybe but up here the supplied dish wouldnt cut it with 28e or 13e in poor weather.

 

[peapod1]

Worked for me too on an 80cm dish near Marseille. In my case I used an Inverto multi-connect with 3 of their slim lnb's. To pull in Astra 2, I had to have that as the prime focus, with 19 and 13 dangling off the end. I had to fix a bracing bar, and beef up the flimsy plastic connection on the back of the lnb, but as they say over there - ca marche!

 

[Ghostleader]

What was up with the interface where the LNB fixes onto the LNB rail that you describe it as flimsy mate?, I had heard good things about that kit aswell (Not from a shop, but a actual user).

 

[peapod1]

What was up with the interface where the LNB fixes onto the LNB rail that you describe it as flimsy mate?, I had heard good things about that kit aswell (Not from a shop, but a actual user).

The single 23mm lnb is fixed to the support arm by plastic clamping plates on the lnb side of the metal bracket. A threaded 'bolt' passes through these into a nut which is held in another plastic bracket in the back of the lnb. This bracket is designed to slide up and down for fine-tuning the positioning. Problem is that it is far too easy to overtighten the bolt which cracks the plastic holding the nut - as I found to my cost. I had to bodge something up to overcome the problem I had created.

 

[Ghostleader]

Thank you for your honesty in regards to your gaff, the only other negatives I have heard about this system is the fact the rail dosnt have any tilt & instead the tracking of the arc is done by sliding the LNB higher or lower on the rail once you have the spacing sorted.

 

[peapod1]

Thank you for your honesty in regards to your gaff, the only other negatives I have heard about this system is the fact the rail dosnt have any tilt & instead the tracking of the arc is done by sliding the LNB higher or lower on the rail once you have the spacing sorted.

Gaff maybe, but I prefer to see it as a design weakness of the securing plate in the back of the lnb. I got it working though, and was pleased to get Astra 2 on the Med coast.

 

[Ghostleader]

Gaff maybe, but I prefer to see it as a design weakness of the securing plate in the back of the lnb. I got it working though, and was pleased to get Astra 2 on the Med coast.

True, any user is going to want to make sure that when the sweet spot is found that the thing is locked in, if you cant do this for the fear of breaking somthing, then maybe they need to upgrade the materials used & maybe the design also.

 

[PaulR]

...and was pleased to get Astra 2 on the Med coast.

I'm only 50 miles further inland and an 80cm, with 28E at centre focus, is enough for all except the very worst weather.

 

[bigtee]

As has been said, a lot depends upon the equipment and the dish in particular. I have a Raven 90 dish focused indeed on 13e and with 7 LNBs getting 8 satellite positions. The extremes are 28e and 1w.

 

[Lazarus]

As has been said, a lot depends upon the equipment and the dish in particular. I have a Raven 90 dish focused indeed on 13e and with 7 LNBs getting 8 satellite positions. The extremes are 28e and 1w.

And equally important is the skill and diligence of the installer!

When it gets milder again, I'm going to try to rationalise SWMBOs dishes, consisting of an old "Sky Analogue" dish with a 13e/19.2E Monoblock, a "Sky Zone 1" for 5W and an A/B switch, by removing the Monoblock and bunging on a generic multi-bracket with 19.2E, 13E and 5W LNBs. Fun.

 

[Rick]

Your going to have to bend the bracket to get a proper allignment on those Tivu, because the 5w LNB will end up too high if you leave the bar straight. It will be an interesting mod to see though

 

[bigtee]

A whole lotta fun indeed ---- especially in more clement weather. Brrrrrrr

 

[Lazarus]

Your going to have to bend the bracket to get a proper allignment on those Tivu, because the 5w LNB will end up too high if you leave the bar straight. It will be an interesting mod to see though

Yes, I have my doubts over it .............. but nothing ventured and all that!

 

[Rick]

I have managed 5e (no nordic beams) 1w and 5w on a TD78 with multi bracket, no modification needed. Not brill levels on any of the three though to be honest.