That depends upon the dish that you are using. You can use several intermediate sized dishes to dabble with C-Band and use a BSC621-2 LNBF (from DMS International) or something related to that model for C-Band reception. However, you truly need a larger dish reflector than 4 feet diameter to do justice. Six feet diameter would probably serve you well in many cases, but depending upon your location, you might require something larger.