I know a dual LNB thing on your dish gives you 2 feeds, but how do they handle it if we want more than 2 feeds? I figured someone here would be able to answer faster than Directv support.
He dates them on seperate nights.
I think you need another dish
I’m not sure what you mean by a “dual LNB thing”, but it doesn’t matter if all you want is to have more than one or two televisions getting a satellite signal. (I think “dual LNB” enables Picture-In-Picture, and might allow you to tape one program while watching another.)
I have a single DirectTV satellite dish. I’m running three televisions off the single feed from the dish. However, at each television you have to have a separate satellite receiver box. The selection of which channel you want to watch is controlled by the receiver. It is like the cable boxes of old.
With a separate receiver for each television, all three televisions can be showing a different channel. All with a single satellite dish.
Now, you could get by with only one satellite receiver, but then all three televisions would be forced to watch the same program.
Or, assuming that “dual LNB” sends two separate channels, you could have two televisions controlled by the “dual LNB” receiver and a third television controlled by a separate “single LNB” (?) receiver.
Each LNB talks to exactly one receiver. If you have a dual dish and more than 2 receivers, you’ll need a multiswitch…www.dbsforums.com can help you out…
yea that makes sense, why do they insist you have a dual thingy rather than a single thingy if you want multiple televisions? It seems you can have multiple tv’s with just one cable coming from the satellite…but they say you have to have 2…if you want 2 or more?
dunno… Makes no sense. Must be a scam.
The dual-LNB thing is because Dish Network has two satellites. The satellites are close enough in the sky (10-degrees, I think) that they can use one dish and two LNBs about 10-degrees apart.
Each cable from the LNB combines with some little gizmo and runs into the one receiver.
If you want to use more than one TV then you have to get more than one receiver. Dish network has a PDF diagram here of how everthing connects. There’s other installation diagrams here to their other setups.
-B
For the record, after going back and looking, you were asking about Direct TV and I answered for “Dish Network” aka “Echostar”.
Never mind…
I have Dish Network, not Direct TV, but it may be similar. I have 1 dish, and 4 boxes for watching separate channels on 4 different TVs.
As it came, the dish had the capability to run 2 decoder boxes, and I paid (and pay each month) a few bucks extra for the extra 2 boxes and the capability to feed them. As you look at the dish, there appear to be 2 “receivers” next to each other, each getting the signal from the satellite. I guess each one of these is a “Dual LNB”, or something similar. The “focus” point of the dish must be wide enough to allow the 2 receivers to both get enough signal. There are 4 coax lines (2 going to each receiver) running from the dish into the house, and then 1 goes to each decoder box.
I was told if I wanted more than 4 boxes, they would need to install a second dish, which could then handle up to another 4 boxes, and so on.
My brother just had Direct TV installed, and from what he told me, it seems to be about the same story.
Ugly
The key piece is the multiplexer on the back of the antenna.
For DirecTV things work like this.
- Dish focuses radio waves for as many LNB’s as you have (I have 3, round dishes can only do one, each LNB hits a different satellite).
- Each LNB picks up vertically and horizontally polarized radiowave. It puts out signals of each polarization on seperate output jacks.
- Two cables from each LNB feed a multiplexer.
- The multiplexer feeds the reciever(s). The multplexer must have an output jack per reciever. The receiver puts a DC bias on the cable connecting it to the multiplexer. Based on the DC bias, the multiplexer choses which LNB/polarization combo to send to the reciever.
- My multiplexer supports 4 receivers, I have them seen them with as many as 12 outputs. Special high capacity units are available for apartments and such.
- A seperate cable must be run for each receiver from the multiplexer. For DirecTV, this is generally located on the back of the dish and isn’t too convenient sometimes.
In summary, the multiplexer allows multiple output (to receivers) to choose one of x number of LNB inputs (6 in my case).