C band interference with Norsat DRO LNB's + Band Pass filters.

[john_robot]

Hi, Currently I am using two Norsat DRO LNB's + Norsat Band Pass filters for C band interference. But still im getting whole lot of interference. I read somewhere that I need PLL lnbs' So guys which of the following LNB is the best ?

5KHz Stability C-Band PLL LNB VS 15KHz Stability C-Band PLL LNB

 

[Titanium]

Phased Lock Loop circuits won't eliminate interference. If the interference is a problem with DRO LNBs, it will likely remain with PLL type.

Maybe the current filters aren't attenuating the correct frequencies? What filter(s) are used? Is the interference below or above of the target downlink frequencies or falling within the TP frequencies?

 

[john_robot]

I'm using Norsat BPF-C-1 Norsat C-Band Band Pass Filter (BPF-C-1), Interference issues happening only on certain transponders. Signals fluctuating from 100 to 0. This happens 3-4 times for 20 - 50 seconds. Its like kind of pattern. I thought its Wimax signals giving the issue. I'm living in the middle of town so many telecom towers in the vicinity. So that is why I thought may be PLL can come to rescue. How to know what frequencies interfering with C band ?

 

[primestar31]

I'm using Norsat BPF-C-1 Norsat C-Band Band Pass Filter (BPF-C-1), Interference issues happening only on certain transponders. Signals fluctuating from 100 to 0. This happens 3-4 times for 20 - 50 seconds. Its like kind of pattern. I thought its Wimax signals giving the issue. I'm living in the middle of town so many telecom towers in the vicinity. So that is why I thought may be PLL can come to rescue. How to know what frequencies interfering with C band ?

You need access to a Spectrum Analyzer to know that. Perhaps you can get some rolls of METAL window screen from the hardware store, and build some shields to place on the side(s) of the dish that are getting ingressed with the interference signal?

Or if you must, MOVE the dish (with pole) to a spot on your property that's behind a building or something that will naturally shield the dish from the interference?

Personally, I'd try the metal screen shields first. If you can actually SEE the towers from your dish site and one is aimed kinda in your direction, that would be the one I'd target with a screen shield.