Dual output C-Band LNBF?

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Mr Tony

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Nov 17, 2003
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Now that I have my C-Band dish up and working (woo hoo!) I want to set up the C-band with 2 or 3 outputs. Couple this with the G10 KU band stuff and I send all the networks to the other rooms in the house :)

But is there a 2 output C-Band LNBF out there? I need something that will do both polarities without having to manually do it.

I know I could just split the line (which is what I planned originally on doing) but I'd prefer adedicated connection and not have to worry about polarity changing accidentally :)
 
One way to accomplish what you want to do is to use a dual feed along with 2 LNBs and a 4x2 multiswitch. A dual feed is made to be able to accept 2 lnbs, one for each polarity and delivers each polarity to one of the LNBs. You can then use a multiswitch like the ones used for directv that has 2 inputs, one for each polarity, and switches between them by 13/18v switching. These switches generally have 2 or 4 outputs and the outputs independently select whichever polarity the reciever connected to them requests.
 
Stefan

I have the switches :)

I have (sitting here or using)
-4x2 multisiwtch (for an Invacom quad running to 2 receivers)
-3 4x4 multiswitches (one is being used..other are here)
-4x8 multiswitch
-10 2x4 multiswitches (2 in use) :)

Thats why I want a dual output C-Band LNBF...but since the nets are on H I can hook just the H side to the switch if I wanted....or split it and use diseqc switches to combine the C line and the KU line
 
dual feedhorn and the switches would work fine on the c band side. You can get them with dual c and ku or just ku but they are somewhat pricy. sometimes you can luck out with some of these companies that takes in and resells cable wreck outs.
 
I've noticed these dual LNB feedhorns on many dishes at local television station dish farms. One LNB sticks straight out, the other points downward. They seem to prefer this method, one advantage is that you can split the outputs from both LNBs (H and V) as many times as is feasible given signal loss. Each LNB has its own, dedicated polarity.
 
Tron said:
I've noticed these dual LNB feedhorns on many dishes at local television station dish farms. One LNB sticks straight out, the other points downward. They seem to prefer this method, one advantage is that you can split the outputs from both LNBs (H and V) as many times as is feasible given signal loss. Each LNB has its own, dedicated polarity.

sometimes they will use the angles to point them in different direction, making it easier to take the lnb off and on. I don't use them, I just leave them off and put them on straight to the feedhorn itself. It's a matter of preference.
 
cablewithaview said:
sometimes they will use the angles to point them in different direction, making it easier to take the lnb off and on. I don't use them, I just leave them off and put them on straight to the feedhorn itself. It's a matter of preference.
I had been wondering how the ones that were parallel to the dish surface would affect signal (if they would block too much of it), but given that I usually see this on 5 meter and larger dishes, I guess its a moot point :)
 
13v is not the "correct" power for C-band lnb...When one is running long cable, it might not work as expected. Putting a 2x4 multi-swithc in between makes it even worse.
With a 6ft dish, he get lock on C-band marginally. Putting a switch in between and under power the lnbs are not good idea...
FtaRock


Stefan said:
One way to accomplish what you want to do is to use a dual feed along with 2 LNBs and a 4x2 multiswitch. A dual feed is made to be able to accept 2 lnbs, one for each polarity and delivers each polarity to one of the LNBs. You can then use a multiswitch like the ones used for directv that has 2 inputs, one for each polarity, and switches between them by 13/18v switching. These switches generally have 2 or 4 outputs and the outputs independently select whichever polarity the reciever connected to them requests.
 
rock
I assume the post was for me?

Other than the networks, the rest come in really good. When I was working on the setup, I used a 35' cable. The run will be a little less (about 25'). I'm going to try the splitter technique and see if that works.

I know I could just plug the cable into the 18v side of the multiswitch and force it to H always but I'd like to scan V too :)
 
ftarock said:
13v is not the "correct" power for C-band lnb...When one is running long cable, it might not work as expected. Putting a 2x4 multi-swithc in between makes it even worse.
With a 6ft dish, he get lock on C-band marginally. Putting a switch in between and under power the lnbs are not good idea...
FtaRock


That's true but it usually works as long as you don't have a long cable run. I use a setup similar to this on my 8.5' birdview, only I use a bullseye type feedhorn and a 4x4 multiswitch for Ku band in addition to C, and even though the Norsat LNBs I use aren't rated to work at 13v they do work for me. Of course with different LNBs the results may vary. Anyway, one way around this issue would be to add power injectors in between the switch and the LNBs.

I agree that a 6' dish is too samll for C band but that's been mentioned here many times before and that doesn't seem to deter those who insist on using a small dish.
 
the 6 footer is working just fine for me :)

I'm not scanning the arc. I stay on G4 and sometimes move east to IA5, G3, IA6 to see what analog is there
 
Iceberg said:
rock
I assume the post was for me?

Other than the networks, the rest come in really good. When I was working on the setup, I used a 35' cable. The run will be a little less (about 25'). I'm going to try the splitter technique and see if that works.

I know I could just plug the cable into the 18v side of the multiswitch and force it to H always but I'd like to scan V too :)


What he says is correct in that most C band LNBs aren't rated to operate at 13v. Anyway this was in regard to my suggestion of using a dual feed and a multiswitch. In that configuration the Vertical polarity LNB would recieve only 13v. The issue is that most C band LNBs are rated to work somewhere in the range of 15-24v. However, I use a similar setup on my 8.5' Birdview and in my experience many LNBs do work okay when powered at only 13v. Of course since it's technically out of spec there's no guarantee it will work but I have an at least 50' cable run and my norsats work fine this way. Anyway, one simple solution would be to add a power injector between the multiswitch and the vertical polarity LNB. This way the vertical polarity LNB would actually recieve the 18v from the power injector but youd still have the 13/18v switching capability of the multiswitch.

The down side to this type configuration is the need for 2 LNBs as opposed to one, a multiswitch, a dual polarity feedhorn, and possibly the power injector if the vertical LNB doesn't want to work at 13v.
 
Power inserter is a good choice in this case, downside is the power injector will degrade the signal as well.
When you lock on the bird marginally, any power injector or switchers are big factors to count on.
Just a head-up so Iceberg won't be supprised if he is no longer to get lock on certain channels when using switcher.
FtaRock



Stefan said:
What he says is correct in that most C band LNBs aren't rated to operate at 13v. Anyway this was in regard to my suggestion of using a dual feed and a multiswitch. In that configuration the Vertical polarity LNB would recieve only 13v. The issue is that most C band LNBs are rated to work somewhere in the range of 15-24v. However, I use a similar setup on my 8.5' Birdview and in my experience many LNBs do work okay when powered at only 13v. Of course since it's technically out of spec there's no guarantee it will work but I have an at least 50' cable run and my norsats work fine this way. Anyway, one simple solution would be to add a power injector between the multiswitch and the vertical polarity LNB. This way the vertical polarity LNB would actually recieve the 18v from the power injector but youd still have the 13/18v switching capability of the multiswitch.

The down side to this type configuration is the need for 2 LNBs as opposed to one, a multiswitch, a dual polarity feedhorn, and possibly the power injector if the vertical LNB doesn't want to work at 13v.
 
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