samc said:
Hi all
I am new here and new to satellite dish arena. What size dish would you recommend for a 36dbW signal?
If you want to be guaranteed to recieve signals on C band you need a dish that is at least 2 degree compliant. You need a dish that's 2 degree compliant because that how closely many of the satellites over the western hemisphere are spaced and the dish must be able to focus in on the one particular satellite your aiming for. Otherwise signals of the same frequency on adjacent satellites will interfere with the signals you want to recieve. To be 2 degree compliant on C band, a dish must be at least 8.5' in diameter. Larger is generally better. Yes, it's possible to sometimes "get by" with smaller dishes that aren't 2 degree compliant in some instances. But whenever that's possible, it's likely just because the satellite in question is in a portion of the arc where the nearest other satellite transmitting on that same frequency is farther that 2 degrees away, That might result when your aiming at a satellite that's in a portion of the arc where the spacing between satellites is greater, like for example Anif F1 or it might just be because the transponders on the next adjacent satellites that are on the same frequency are inactive at the time. If it's the later and those transponders ever do become active the person using the undersized dish is gonna have a problem. So, that's why you need at least an 8.5' dish.
Also note that signals strength really doesn't necessarily matter with regard to this issue, because signal strength is not the issue. Interference is. Therefore even if the signal you want to receive is "strong", if there's another "strong" signal on the adjacent satellite on overlapping frequencies youd likely have a problem with an undersized reflector.
Having said that there are some situations where an undersized reflector might work. One example might be some of that atlantic satellites which in some cases are spaced farther apart. Anyway, as to whether a smaller dish will work for the signal your interested in what satellite it's on and the spacing between it and the nearest other C band satellite might be a better thing to look at than signal strength.