LNB frequencies for C band Vs Ku

[kelleyga]

I have a 10 feet C band setup using a Chaparral Feedhorn. I also have a DMS 621 Feedhorn. I know that I would be able to watch either Horizontal Channels or Vertical Channels at one given time. So lets say I have a switch, 2 receivers and the dish is parked at X satellite.

If I turn Receiver 1 (R1) to a Vertical Channel and then I turn Receiver 2 (R2) to a Horizontal channel, only one of the receiver will show something.

Now, will that be the same case for Ku lnb (other than the Chapparal or DMS) I mean regular Ku Lnbs like the ones that look like the dishnetwork or directv?

I want to set up a Ku setup with a 90 cm dish I just bought, but I would like to use a switch and be able to see different frequency channels at my two receiver when I have the dish pointing to a specific satellite?

So, would the regular universal Ku lnbs behaive like the dishnetwork or directv lnbs that I "guess" download both the vertical and horizontal signals at once?

 

[Anole]

okay, I'll take a stab at that ...

I want to set up a Ku setup with a 90 cm dish I just bought, but I would like to use a switch and be able to see different frequency channels at my two receiver when I have the dish pointing to a specific satellite?

Ku band -
You would get Standard or Universal Ku-band LNBs with two outputs.
Then, two receivers could each choose opposite polarities.
If you have more than two receivers , you put a 2x4 or 2x8 multi-switch to the two LNB ouputs, and feed four or eight receivers.
Should be explained in the Switches Simplified thread in the FTA FAQ section.

I have a 10 feet C band setup using a Chaparral Feedhorn. I also have a DMS 621 Feedhorn.

C-band -
Neither would do the job.
You could use any of the following.
- SatelliteAV dual output C-band LNB (and maybe a 2x4 multi-switch)
- Chaparral Bullseye I feedhorn, with two LNBs, and a multiswitch
- Sadoun sells a band-stacked C-band LNBf, but that would require more explanation.


C and Ku on one dish -
If you want to run both C and Ku on one dish, with multiple receivers, then an expensive Chaparall Bullseye II , with two C-LNBs, and two Ku-LNBs, along with a 4x4 or 4x8 multiswitch would be required.

There may be other solutions I haven't thought of, but that should get you started.

 

[Mr Tony]

If I turn Receiver 1 (R1) to a Vertical Channel and then I turn Receiver 2 (R2) to a Horizontal channel, only one of the receiver will show something.

the 621 only has one output so you get either vertical or Horizontal at one time. You would need a dual LNB to get both at the same time.

Now, will that be the same case for Ku lnb (other than the Chapparal or DMS) I mean regular Ku Lnbs like the ones that look like the dishnetwork or directv?

you would use a dual LNB but yes they would work where you can get both polarities at once

I want to set up a Ku setup with a 90 cm dish I just bought, but I would like to use a switch and be able to see different frequency channels at my two receiver when I have the dish pointing to a specific satellite?

so 2 fixed dishes? shouldnt be too hard. Anole already posted a link to the switch matrix

 

[kelleyga]

this is what I got.

A 90 cm dish.
1 ITB (Cheap) Ku-Band LNBF 1 output only
2 receivers (Pansat 3500 , Fortec Mercury II)
1 diseq

THIS IS WHAT I WANT:

Lets say I park the dish at Pansat 3r and skan for Ku channels. I get Vertical and Horizontal.

I want to be able to connect the only output from this LNBF to a 4 port diseq and from there run 2 cable, one for the Fortec and the other one for the Pansat. Then I want to be able to Watch a vertical channel in the fortec and a horizontal channel in the pansat, or viceversa.

That should work right?

 

[Mr Tony]

nope...diseqc doesnt work that way...it allows you to have 4 LNB's on one box

you NEED a dual LNB to watch opposite polarities on one LNB with both boxes.

 

[kelleyga]

well, what if I add a third or fourth receiver? The Dual lnb will not work then.

What do I need to make it work with 4 receivers?

 

[Mr Tony]

yes it would...add a 2x4 or 3x4 multiswitch to the mix...heck they make 2x16

 

[kelleyga]

man, I got all confused since the begining. I meant a multi-switch as anole was talking about instead of a diseq. Well, is kind of late I better go to sleep.

But thanks for your help I really appreciate it.

 

[Mr Tony]

here is how to hook up multiple boxes to one LNB...it shows two but you could use just one if wanted to
http://www.satelliteguys.us/1344314-post7.html

 

[melgarga]

I think the part your missing is that in order to have both polarities at the same time you need 2 outputs available. Once you have this, the switch configuration selects which irds are looking at which lnb at any given time. After that the tuner 'picks' the chosen tp freq from the 'block' of downconverted signals, so any freq in that polarity on that output can be recieved and not interfere with whatever is being recieved on the other output. Clear as mud, eh?
Also, the pay dvb stuff does not pickup both polarities at the same time either. Circular LH or RH is selected via a voltage shift on the coax to the lnb. It is transparent as switching goes but if the 13/18 volt shift did not occur, then only the one selected would be received. I forget which voltage does which polarity.

 

[Tron]

13v is vertical and 18v is horizontal. There is an exception where you could use a single output LNB to feed multiple receivers, but the LNB would have to be a "stacked" LNB such as the FSS Ku LNB found on a Superdish. These send both horizontal and vertical polarities down at the same time by "stacking" the horizontal transponders in a higher frequency range above the verticals. Since the horizontal transponder frequencies would therefore be different, you'll want to either use a blind scan receiver to find them or subtract the original horizontal transponder frequency from 24600.