Cascade said:
To be honest the noise figure alone doesn't make a good LNB, it's clear the Invacoms are by far the best LNBs overall and their low noise figure is just part of what goes into making a great LNB.
Right now I'm interested in what people think of a lower noise figure LNB, whether the noise figure alone is enough to sell an LNB or whether other factors influence their decision.
Edit: to answer the question I don't know the difference until I get one, I'm also looking at quad-universal LNBs and octo-universal LNBs.
I think in a world of excessive marketing speak and one-upmanship specification writing the only way to actually know which is better is to try them out side by side and systematically compare quality readings on your favourite transponders. And even then it is only a sample of one LNB.
In my opinion there is not much difference in a NF of 0.5, 0.4, 0.3, 0.2 - specified in "typical" values!? Other specifications are just as important. One which leaps out at me when I compare LNB's on paper is the Oscillator Phase Noise. Between different "0.3 NF" LNB's (Invacom and MTI Blueline which is another well regarded consumer LNB) the values were very different although one had maximum and the other typical specified. As someone who, in a previous life, designed the IF strip (part that converts 950-2150 MHz to digital) of commercial Satellite receivers the difference of 10-15dB reported between the 2 LNB's is HUGE. I would like to suggest that this is why the Invacom LNB's seem to perform so much better than many other LNB's. Essentially it adds less garbage to the signal when it downconverts from ~12GHz to ~2GHz.
Thus, in many words, I completely agree with you.
Very soon I hope to add my two cents on the performance gains of an Invacom to my cheap unknown brand LNB in my setup/location. But mostly I got it for it's universal capabilities.