Smart Search weirdness

[Mr Tony]

I decided to do a smart (blind) search on SatMex 5 (116.8) just to see what was on there. What was weird is that it also picked up some TP's that had a SR of 20.000 (which would be a DBS satellite) and then when it did its scan, it would pick up the stuff on the Dish 119 TP's that it stored. (those 12 channels that have nothing on them but show up in the guide so you have to delete 200 channels).

How could a universal LNBF set to 10750 pick up a DBS bird that needs a circular LNBF set to 11250??

 

[Tom Taylor]

A symbol rate of 20k is quite common, Dish uses it as well as Globecast. The higher the number, the more channels theat can be put out on the same transponder. It is sort of like baud. Most of the 30 inch dishes that are used have such a wide beam that a good blind search receiver will grab a signal from neighboring birds, G3 and T5 are good examples. Even though a good blind search receiver will delete most of the junk you will need to delete some unwanted channels.

 

[Mr Tony]

Tom
On my Pansat 1500 when I do a search, I have to tell it what LO frequency to use and I always have it at 10750 9except for Nimiq1 and Dish 119). So how can it pick up the DBS bird at 119 that has a LO of 11250? I never have this problem when I scan 121

 

[Tom Taylor]

10750 is close enough, the downlink frequency that your receiver identifies will be off a bit but it will work, you will lock on the DBS signals. A good lnbf will operate out of its intended frequency range.