Dual LNB offset bracket

[swyman18]

This is probably really dumb question. I am going to try my first attempt at installing a second ( and possibly third) Ku LNB on my GeoSatPro 90cm dish. I got one of these dual brackets pictured below and from what I’ve read, I am supposed to physically bend the bracket up or down to line up with the sats I want to receive. Is that correct?

I am located in Hawaii (longitude 155w) and I want to see if I can get both 91w and 87w on the same dish. I know that may be a stretch considering how low to the horizon those sats are for me.

The metal seems too thick to really be able to bend the bracket without doing some damage to the lnb arm. My skew for these sats would be about 67 degrees, so that’s quite a large bend.

I just want to make sure I’m on the right track with this, physically bending the bracket doesn’t seem right to me.

Thanks.

 

[Magic Static]

4° on a 90cm dish is almost impossible without some special narrow feedhorns on the LNBFs. And close to the horizon even more difficult. GeoSat made some Bullet LNBFs that were intended for multi-sat configurations, but they are no longer available. They had a special bracket made to hold two Bullets at 4° separation. A lot tighter than the bracket you have now.

 

[Magic Static]

Not much on 91W Ku. I scanned it yesterday and found one interesting feed. Labeled Ford Bronco, Ford was filming the new Bronco in off road trials.

 

[a33]

The metal seems too thick to really be able to bend the bracket without doing some damage to the lnb arm. My skew for these sats would be about 67 degrees, so that’s quite a large bend.

I'd skew the whole dish, then, if possible. So that the angle of the multifeedrail against the arm, is perpendicular again.
(Or use the gpflepsen setup, as here: A way to deal with offset dish aiming in difficult situations )

But note the Magic Static post about 4° on a 90cm dish ! That would be the first thing to consider.

Greetz,
A33

 

[comfortably_numb]

4 degrees works for me on a 1.2m but not a 90cm.

That being said, I have bent those exact same brackets before for the purpose as you have described on my 1.2m dish.

It's a process of experimentation. A 6° or 8° separation works pretty good on a 90 cm, for instance 97/103.

 

[comfortably_numb]

Not much on 91W Ku.

depends. This past weekend, there was quite a bit of activity on 91. Seems like the feeds are becoming weaker though, so I've got the 1.2 pointed at it right now.

 

[swyman18]

Thanks all, will take the suggestions into consideration.

 

[c-spand]

I would tune 91 first then try to add 87w. Try www.satbeams.com 87 is at 10.5 elevation but being in the islands you have nothing in the way. I have heard from other people that getting under 10 degree elevation is very difficult. But being where you are should be fine. Need a 35 inch or more dish. you should go threw and just single lnb threw the arc and bank the channels. Start with the easiest from there and go towards 87. Say 129w has reuters start there and work all sats in to 87. Good luck. Curious what you can get.

 

[comfortably_numb]

Here are some photos showing how to do offset LNB's on your 90cm GeoSat Pro. Note: I have not had success running more than 3 LNB's total on that dish. Most signals are DVB-S2 now and won't be picked up by LNB's pointed so far off the center of the dish.

 

[c-spand]

wow

 

[swyman18]

I would tune 91 first then try to add 87w. Try www.satbeams.com 87 is at 10.5 elevation but being in the islands you have nothing in the way. I have heard from other people that getting under 10 degree elevation is very difficult. But being where you are should be fine. Need a 35 inch or more dish. you should go threw and just single lnb threw the arc and bank the channels. Start with the easiest from there and go towards 87. Say 129w has reuters start there and work all sats in to 87. Good luck. Curious what you can get.

I have another 90cm dish on a STAB HH90 motor and I am able to get from 125w down to 97w on there. Anything lower is outside of the motors physical limits.

I have the other 90cm dish pointed at 91w and wanted to try out the bracket to see what else I can add on there.

 

[swyman18]

Here are some photos showing how to do offset LNB's on your 90cm GeoSat Pro. Note: I have not had success running more than 3 LNB's total on that dish. Most signals are DVB-S2 now and won't be picked up by LNB's pointed so far off the center of the dish.

Thanks for the pics. So did you have to physically bend the bracket up or down in any of those configurations? Looks like probably not necessary based on your location?

 

[comfortably_numb]

Thanks for the pics. So did you have to physically bend the bracket up or down in any of those configurations? Looks like probably not necessary based on your location?

Correct. I only bent one for experimentation purposes. You can slide the LNB along the offset rail and make adjustments that way.

 

[LocutusOfBorg]

I've been considering doing something similar on my 12 footer for C-band but for 4 or more sats. I could use a second motorized 12 footer but it's more work than this old man wants to do.