Dear friends,
since a long time I use a Chapparal OMT in which I use one Norsat 8515 LNB that has a 15 K noise figure. The other is from an Indian firm using the name of the formerly renowned US company Gardiner.
Considering to replace the latter by another Norsat I assumed that it might be good to use a somewhat newer and therefore supposedly better but what I just find out while reading the specs of other more expensive types, be it with greater frequency stability or PLL-based, that they mostly indicate a 20K noise figure.
For me sensitivity is of greatest importance. Since C-Band streams have been introduced I discover a.o. on SES 5 (5E) and Eutelsat 10 (10E) that my 10 ft Unimesh dish seems to underperform in that area while doing great with regular transponders. There doesn't seem to be a relation to the bandwith that is used so I tend to go for sensitivity over stability but perhals I'm wrong by this assumption?
I also note that a sample of the 8515 that is sold new on Ebay now states that it's noise figure is 20K and even one that states that it's noise figure is between 15K and 30K.
What should I conclude? It seems hardly likely that Norsat isn't able anymore to produce the same noise figures as before. Could it be that there is no difference and that the 15K indication from before was overly optimistic? Why would it be that an LNB that's sold for double the price has a less good noise figure? And what role plays the PLL built? I only have experiences with an Octagon universal Ku-Band PLL LNB but found it to perform less well than my regular Black Ultra LNB. That experience made me doubt the value of PLL very much. In C-Band I have no experience with PLL-based LNB's.
In any case, considering my limited resources, would it be advisable to simply purchase another used 8515 at hopefully a bargain price (if anyone has one for sale please PM me) or is there a Norsat model that would perform very notably better than the 8515 @ 15K?
since a long time I use a Chapparal OMT in which I use one Norsat 8515 LNB that has a 15 K noise figure. The other is from an Indian firm using the name of the formerly renowned US company Gardiner.
Considering to replace the latter by another Norsat I assumed that it might be good to use a somewhat newer and therefore supposedly better but what I just find out while reading the specs of other more expensive types, be it with greater frequency stability or PLL-based, that they mostly indicate a 20K noise figure.
For me sensitivity is of greatest importance. Since C-Band streams have been introduced I discover a.o. on SES 5 (5E) and Eutelsat 10 (10E) that my 10 ft Unimesh dish seems to underperform in that area while doing great with regular transponders. There doesn't seem to be a relation to the bandwith that is used so I tend to go for sensitivity over stability but perhals I'm wrong by this assumption?
I also note that a sample of the 8515 that is sold new on Ebay now states that it's noise figure is 20K and even one that states that it's noise figure is between 15K and 30K.
What should I conclude? It seems hardly likely that Norsat isn't able anymore to produce the same noise figures as before. Could it be that there is no difference and that the 15K indication from before was overly optimistic? Why would it be that an LNB that's sold for double the price has a less good noise figure? And what role plays the PLL built? I only have experiences with an Octagon universal Ku-Band PLL LNB but found it to perform less well than my regular Black Ultra LNB. That experience made me doubt the value of PLL very much. In C-Band I have no experience with PLL-based LNB's.
In any case, considering my limited resources, would it be advisable to simply purchase another used 8515 at hopefully a bargain price (if anyone has one for sale please PM me) or is there a Norsat model that would perform very notably better than the 8515 @ 15K?
