FM Bandstop Filter for RTL SDR
The given FM band stop filter is nothing more than a simple Band stop filter for the frequency range of 88-108Mhz. FM Broadcast transmitters transmit at high power and can cause overloading and intermodulation problems on simple receivers like RTL-SDR due to its wide open front end. The said is more problematic particularly during weather satellites reception and if transmitters are very nearby. The simplest solution to reducing overloading problems due to above is build an FM stop filter. This is simply a band stop filter that blocks frequencies between 88 – 108 MHz from entering into your sdr. This circuit show how to build a home made FM trap out of cheap common parts available in everyone shack. Even though this circuit uses smd parts, one can use equivalent through hole components without much trouble. But leads from through hole components should be short to avoid stray capacitance.
Source
http://lna4all.blogspot.com/2015/10/diy-fm-trap-or-88-108-mhz-band-stop.html