From my very limited experience I will say that tuning the dish to 2F and making sure everything is aligned right could make a difference, we were on the roof with a promax and my installer was showing me the difference between pointing the dish at 1N and 2F, he was adamant with me on this point ( that on the spectrum analyzer you could tune one sattelite or the other for maximum signal ) and showed me some .4db difference on a 1.6m offset from 2F if it was tuned to 2F / 1n alternatively. I was amazed that the dish could pick that out at 36000km , were talking leaning on the dish slightly but taking that at face value , I would imagine on a quality focussed dish this is larger ( ? ) though how larger i dont know. That negative in portugal on a 2m is indeed surprising but not the first report from this area of variation over a short distance in central west portugal. I was also surprised at the difference between a black eco and black ultra.. i have one of each and the black ultra performed better giving a higher dB SNR.