multi lnbs on one dish?
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Here is a recent thread with photos:
http://www.satelliteguys.us/threads/301247-Mini-BUD-C-band-Project-99w-91W?highlight=91w+99w
Doubt that you will be able to get that combination of 103, 99, 97 as the satellites are too close together to place LNBFs close enough.
http://www.satelliteguys.us/threads/301247-Mini-BUD-C-band-Project-99w-91W?highlight=91w+99w
Doubt that you will be able to get that combination of 103, 99, 97 as the satellites are too close together to place LNBFs close enough.
I just reread Brian's old thread from January.
Lots of spot-on info, there. Very applicapable.
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Dan:
Also, you might want to free up some space in your PM mailbox.
Brian:
What about inverting the dish to cure the LNB drainage problem?
Lots of spot-on info, there. Very applicapable.
edit -
Dan:
Also, you might want to free up some space in your PM mailbox.
Brian:
What about inverting the dish to cure the LNB drainage problem?
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I have an 1.8m dish and two LNBs mounted in; one catchs the Galaxy16 (99.2W), and the other catchs Galaxy 3C (95W). I tried to catch also SES1 (101W), but I had no success. Too close to 99W I think (or bigger dish required). In another configuration, I was catching Galaxy3C (95W) and Galaxy17 (91W).
It seems not so dificcult to catch 2 or 3 satellites (signal not too weak) 4 degrees away one from another with a 1.8m dish (one LNB Centered with another in each side). If your dish is bigger, it will be easier, I think. Not sure if there are only 2 degrees between two of the satellites, or more than 15...
It seems not so dificcult to catch 2 or 3 satellites (signal not too weak) 4 degrees away one from another with a 1.8m dish (one LNB Centered with another in each side). If your dish is bigger, it will be easier, I think. Not sure if there are only 2 degrees between two of the satellites, or more than 15...
Well, it depends.... I have my 2.4 meter dish pointed at 99W, and the additional LNBF in my avatar is for 105W, to receive H2H. Notice that it is mounted a over an inch away from the scalar. When trying to find 105W, I put the LNBF up against the scalar and got a signal there, it was 103W. I would have needed to cut into the scalar to optimize at 103W, so 4 degree separation can be possible, but like others say, it depends on the dish.
If memory serves, Iceberg did a number of two- and three- LNBF C band experiments on his 6'er, several years ago.
Might be instructive to search for those.
Over the years, we've had many great discussions on multi-LNBF setups.
One member posted some simple equations to solve the problem.
I studied 'em and promoted their use many times for quite a few years.
One thing you immediately see, is that longer focal length dishes work better for close satellites.
And if you look at enough BUDs, you'll notice there are two kinds:
- deep dish, where the scalar is close to the dish rim
- shallow dishes, where the scalar is far skyward from the dish rim
The shallow dish would be a better candidate for multi-LNBF use.
As a rule of thumb, Ku dishes are more similar than different.
So, you go for a bigger dish to get a longer focal distance.
ie: a 1.2m is a better choice than .6m dish.
Might be instructive to search for those.
Over the years, we've had many great discussions on multi-LNBF setups.
One member posted some simple equations to solve the problem.
I studied 'em and promoted their use many times for quite a few years.
One thing you immediately see, is that longer focal length dishes work better for close satellites.
And if you look at enough BUDs, you'll notice there are two kinds:
- deep dish, where the scalar is close to the dish rim
- shallow dishes, where the scalar is far skyward from the dish rim
The shallow dish would be a better candidate for multi-LNBF use.
As a rule of thumb, Ku dishes are more similar than different.
So, you go for a bigger dish to get a longer focal distance.
ie: a 1.2m is a better choice than .6m dish.
Find yourself a nice elliptical Primestar dish, and mount a length of electrical e.m.t. tubing in place of the center lnb. Then, use e.m.t. hangers, to mount the lnb's. Aim the dish at the CENTER satellite of the group you want to catch, and you should be able to get the 2 degree spacing you need.
Remember, the sat signals will cross-over to the opposite lnb, and you might have to raise or lower certain ones to peak the signals on whatever sat they are meant for.
Like this, I borrowed this pic from another site.
Here's another showing what I mean: http://www.flickr.com/photos/netbuilder/1848936980/
Remember, the sat signals will cross-over to the opposite lnb, and you might have to raise or lower certain ones to peak the signals on whatever sat they are meant for.
Like this, I borrowed this pic from another site.Here's another showing what I mean: http://www.flickr.com/photos/netbuilder/1848936980/
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clucas Do not like motorized system? Want multifeed? Look for antenna which is designed for that..... such as Wave Frontier T90. Of course, it is possible to mount several LNBs on usual offset antenna, but performance will not be so good. Of course, GeosatPro 1.2m is better performer than 33"x36" elliptical dish.
Multifeed is faster and no moving parts. Had a motorized system years ago and it worked well until the motor died. I have to consolidate dishes. I have 3 Ku and 3 C band (8 1/2, 10 and 12) in a town that limits me to one dish. Lucky the neighbors have not complained.
Thanks for all the suggestions.
Thanks for all the suggestions.
Dan the man the best combo is putting 97 in the middle and 91 and 103 you can do this best with Casey's lnbf brackets 2 of them. The other way to do it is with a larger dish put 87 center and then 91 and 97 on the end. I have done it both ways. Now I am giving Dan the man some advice.
PS. GO TO KE4EST FOR A MAV STANDARD LNBF!
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I have managed to do 4 degree spacing on a 1m dish making my own mount and getting creative. But i must stress that if it wernt for the specifics there is no guarantee it will work at all. The positions in question are 125w for the main sat position and 121w for velocity. I think it works because velocity is so strong and its also KU. I dont know how well or how far apart you can receive c-band signals and its not been a huge issue since i have the 10' dish motorized.
On a 90cm, i am successfully getting 118w 121w and 125w
On Cband, I only have one dish doing multiple positions thus far... 91w and 97w
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