Hi there folks! o/ I designed a 69.450 MHz 3 MHz wide Band-Pass filter, in order to use as a narrow band filter for a SDR. Schematic: In theory everything was great and perfect. See the LTSpice simulation: Exactly what I wanted. Yay, right. Not so fast. As a frequent QRZer here signs in his posts, theory only works in perfect vacuum. This is actually what I got in a 40-80 MHz sweep: Well, the filter actually eat 100% of the signal. Nothing comes out of it. Heck of a filter, right. Here is the filter PCB layout: The red line depicts the "passthrough" mode - The signal enters the first RF switch and moves straight to the 2nd RF switch, untouched. This pretty much rules out the RF switch issue. SO. My forum question. Can you actually envision what is wrong in this filter design? What am I missing? For completeness, these are the filter components: 2400 pF cap - https://www.digikey.com/product-detail/en/kemet/C1206C242J5GAC7800/399-14673-1-ND/7103965 2.2 nH ind - https://www.digikey.com/product-detail/en/abracon-llc/AIMC-0805-2N2S-T/535-11562-1-ND/2782791 2.2 µH ind - https://www.digikey.com/product-detail/en/tdk-corporation/MLF2012A2R2KT000/445-1051-1-ND/504449 2.4 pF cap - https://www.digikey.com/product-detail/en/kemet/C0603C249D5GAC7867/399-14972-1-ND/7382521 Help? I appreciate the help o/ 73 de PY2RAF - Rodrigo.