Can anybody explain or give me a reason for weaker reception on lower frequencies? I can receive very weak transponders at around 12.300 GHz but the same power transponders lower down the spectrum are either non existant or breakup. I've tried different LNB's and even another dish, can it be down to length or type of cable? I have a run of about 25m of cable. This problem happens on various satellites too. I'm using an Echostar AD3000IP.