Filter needed?

[davewill2010]

What’s the easiest way to determine whether I would benefit from a filter?

I can supply Graphs1090 output if that helps?

Iam using the Blue Pro Stick Plus.

Thanks

[chrislfa]

I’ve found that the best way is to get one and see if it makes any difference. I also have that stick and for me the dark blue filter just reduced numbers all around, despite having some strong GSM signals nearby. So I removed it and numbers went back up. Worth noting that the blue stick has some filtering already, so perhaps further filtering is less relevant for this stick.

[kmm0000]

Check this thread.

Do I Need A Filter?

The space around ADS-B antenna contain not only 1090 MHz signals, but also lot of other signals at different frequencies. The closer the frequency of a signal to 1090 MHz, your ADS-B antenna picks it stronger. For example if there are three signals of equal strength, one at 144 MHz, 2nd at 850 MHz and 3rd at 950 MHz, the ADS-B antenna will pick 950 MHz one the strongest, 850 MHz one a bit less stronger, and 144 MHz one much fainter. As the Cell/Mobile/Pager signals exist in the range 850 MHz to…