Smallest dish size for C Band
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you can find many small sizes but for a decent C/Ku setup i say no smaller than 8.5' but prefer 10' for $100 more. or you can scout your area for free 10' dishes that the unknowing gave up on and never had removed, just update the feed & lnbs.
Depending on the satellite footprint, the power of the satellite, and your location you can go as low as 5'. However, with a dish that small you are likely to receive only a few satellites with a good signal. 8' is rather the standard size, but some go with 10'-14' dishes to pull in some sats with very low signal over the US. In the late 80's I was able to receive a very snowy picture from one of the Intelsat satellites over the Atlantic Ocean with an 8' here at 80 degrees west. Of course things have changed and receiving those sat locations are fairly easy now.
I would recommend that anyone considering getting a C-band Dish get a 10ft. dish and not try to see how small you can go, satellites used to be spaced farther apart then they are now and with a too small dish you will have problems with adjacent satellite interference. The minimum size to work with the 2 degree satellite spacing we have now is about 81/2 ft. but you must be very precise on your alignment, a 10ft. properly aligned is even better.
I have a 4 foot dish that I would like to play with for C-Band just because it was free, it is an offset channel master 1.2M. What type of LNBF would I need to get for it? All of the ones I find are Primefocus and I know I need an off set.
Also can somone detail what the major advantage between prime focus and offset dishes are?
Thanks
Wholeshoe
Also can somone detail what the major advantage between prime focus and offset dishes are?
Thanks
Wholeshoe
prime vs. offset dishes
The major difference typically is efficiency. The amount of signal actually reflected to the lnb. Offset dishes are typically more efficient than prime focus. Mainly because with a prime focus dish the struts that hold the feedhorn assembly block some of the signal.
Also an offset dish picks up less thermal earth noise lowering the noise floor level so that less signal has to be received to overcome the natural thermal noise from our planet. On a prime focus dish especially the wire mesh type the lnb will pick up some noise from the ground since it can "see" somewhat through the mesh as where an offset dish's lnb looks upward at a solid dish that is typically "cooler" than the ground surface.
In most cases in comparison prime focus vs offset the offset dish of somewhat smaller size will perform equal to a larger prime focus.
However don't misunderstand me, you cannot use a 75 or 90 cm dish and pick up c-band signals that would normally require an 8.5 foot or larger dish.
Hope that helps a little.
The major difference typically is efficiency. The amount of signal actually reflected to the lnb. Offset dishes are typically more efficient than prime focus. Mainly because with a prime focus dish the struts that hold the feedhorn assembly block some of the signal.
Also an offset dish picks up less thermal earth noise lowering the noise floor level so that less signal has to be received to overcome the natural thermal noise from our planet. On a prime focus dish especially the wire mesh type the lnb will pick up some noise from the ground since it can "see" somewhat through the mesh as where an offset dish's lnb looks upward at a solid dish that is typically "cooler" than the ground surface.
In most cases in comparison prime focus vs offset the offset dish of somewhat smaller size will perform equal to a larger prime focus.
However don't misunderstand me, you cannot use a 75 or 90 cm dish and pick up c-band signals that would normally require an 8.5 foot or larger dish.
Hope that helps a little.
Actually 8.5' is about the smallest size for proper C-band reception in most of parts of North America larger in other areas, a 8.5' reflector will eliminate adjacent satellite interference, and the stronger birds being used now, make a smaller sized reflector almost useless.
Try pointing the dish around and put a Feedhorn on a stick and hold it in front of the dish. You may get some analog stuff?
Solid or mess?
snow collects less on an offset.
Solid or mess?
snow collects less on an offset.
Wholeshoe said:
Actually now that I went back out there and looked at it, I think my C-Band dish is 6 foot or so. Its one of the smallest C-Band dishes that you will see but a bit larger than the SuperDish.
Wholeshoe said:
A lot of us testing mini bud are using prime focus LNB's or LNBF's .
I saw a post listing a url for a place for offset dish C band LNBF , http://www.eyeinthesky.net/ , but it was ( if I recall ) twice as $$$ .
I am testing a 15 degree LNB & 90 cm dish with some results . I have to admit it is marginal , but fun . And I have only spent about $ 30 on it .
Wyr
How about those phased array and round C-Band dishes that were a bit smaller that I saw a while back?
My C band setup was going off & back on . Started replacing components , last thing I replaced about midnight , last nite was the 15 degree LNB . Replaced it with the 30 degree California Amplifier LNB that came with the Chapparel feed horn / polarotor ( that I bought used off of fleabay ) .
Everything started working and has continued to work ever since . But the signal does not seem to be as strong , which I kind of expected . That is why I bought the 15 degree LNB in the first place .
Wyr
Everything started working and has continued to work ever since . But the signal does not seem to be as strong , which I kind of expected . That is why I bought the 15 degree LNB in the first place .
Wyr
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