c-Ku

[Curtisstarr]

My question is whether I need a 6' dish always to recieve a c band station. there is really one that I am interested and the lyngsat information told me that a smaller dish would be acceptable. Any comments?

[rainman]

Originally Posted by Curtisstarr

My question is whether I need a 6' dish always to recieve a c band station. there is really one that I am interested and the lyngsat information told me that a smaller dish would be acceptable. Any comments?

if you want to receive c band you will need at least 6' dish 8.5' recommended.

[William Eng]

The technical way to do it is look at the footprint map of your satellite of interest and match the corresponding signal strength to the dish requirement for your location. Bigger is better as others will tell you. Do it right the first time, and you won't regret having to put up with weak signals and loss of signal.

[ayelvington]

Friend, I believe that you are honestly mistaken on the relationship between dish size and spectrum. I have a 1m prime focus dish for S-band that works quite well.

What this question calls for is a link budget for the satellite, gain of the LNB, and knowledge of the characteristics of the dish the user wants to use. There are small prime focus dishes available out there, and offset dishes (1.2m +) can handle a C-band LNBF.

Is there someone out there with a solid RF engineering background that can help this user with the math?

A. Yelvington

[wejones]

Originally Posted by Curtisstarr

My question is whether I need a 6' dish always to recieve a c band station. there is really one that I am interested and the lyngsat information told me that a smaller dish would be acceptable. Any comments?

? You say "there is really one that I am interested" ... do you mean that there is one station you are interested in? If so, what station on what sat?

In general though, I agree with the recommendation that you need at least 6', and in my opinion, the Lyngsat dish size recommendations for C-band are WAY off. However that depends a bit on exactly what transponder or sat you're trying to receive, and with what receiver. There are some people here who have used a 4' dish for C-band, but with a dish that small, you will not get all channels. Some people have also reported receiving some C-band with a 3' dish, however if you're talking about receiving video one of the satellites that are over the US, I would say that the odds are against you being able to receive anything with a 3' dish, unless it is a very strong narrow band channel without any nearby interferrence.
The problem with respect to receiving C-band with a 3' dish is that with a 3' dish, in addition to the fact that the dish gain is about one third of the gain for Ku, you are basically receiving about 5 sats at the same time, instead of just one, because the beamwidth is so much wider. So instead of just trying to get a reasonable signal to noise based on normal background noise, you have all the noise coming from the adjacent satellites as well.
So unless the particular "station" you're looking for happens to be very strong, and a very narrow signal that doesn't happen to have any interferring signals on adjacent sats, then the odds are not with you.

[elgemcdlf]

Originally Posted by ayelvington

Friend, I believe that you are honestly mistaken on the relationship between dish size and spectrum. I have a 1m prime focus dish for S-band that works quite well.

What this question calls for is a link budget for the satellite, gain of the LNB, and knowledge of the characteristics of the dish the user wants to use. There are small prime focus dishes available out there, and offset dishes (1.2m +) can handle a C-band LNBF.

Is there someone out there with a solid RF engineering background that can help this user with the math?

A. Yelvington

I guess the whole thing comes down to the definition of the relative phrase "works quite well". Works quite well compared to ? A .5m dish? I would imagine so. A 12' dish I imagine not. After all without any math and just a little thought there must be a reason the big boys with all the money have big dishes. I think if they could get away with smaller less expensive equipment they would.

[wejones]

Originally Posted by elgemcdlf

I guess the whole thing comes down to the definition of the relative phrase "works quite well". Works quite well compared to ? A .5m dish? I would imagine so. A 12' dish I imagine not. .....

Right. And also works quite well with what source. Ie you don't see video sent by S band over relatively low power satellites spaced 2 degrees apart, and there is a good reason for that. If there were only 2 or 3 C-band sats up there transmitting at twice the power, then yes, you could probably get some reception with a 3' dish. Almost any size dish will "work" with C band, but if you're talking about video reception from conus satellites, "work" has a different meaning.

Like you say, no fancy math required. When C-band is compared to Ku, the gain is about 9 db less, and the beamwidth is about 3 times wider, both of which mean you need a bigger dish.

[rainman]

yep when it comes to c band digital even my 8.5' dish has some tilting.
hum: maybe a 12 footer in the future

[Curtisstarr]

"without any math and just a little thought there must be a reason the big boys with all the money have big dishes. I think if they could get away with smaller less expensive equipment they would.[/quote]

Thanks for all the information. I thought that the Lyngsat information may be a little misleading. I want to recieve TVJapan and apparently outsde of the Dish Network, the only reception is c band on Galaxy13/horizons1. The problem is that I can't have a 8.5' dish at the townhouse in VA. It seems that my original question was answered, and I definitely will put up the large dish at my place in NC.