I think the difference is that a true "blind search" receiever will scan for frequency and symbol rate to begin with and then scan those frequencies and symbol rates for channels as opposed to a non blind search reciever which simply scan for channels either form a preprogrammed list of frequencies and symbol rates or from frequencies and symbol rates you program into it. So, in other words a true blind search reciever will find (or try to find) the frequency of the transponders to begin with and will attempt to find the symbol rate and then go on from there to find channels contained in those streams whereas a non-blind search reciever may need to already know what frequencies and symbol rates to scan for channels. Anyway, that's my understanding of it.