Notch Filter Module High Q Filter Out 50hz Signal Power Frequency Signal Two Levels Of Notch Depth Adjustable Filter - Demo Board Accessories - AliExpress
The Active Universal Filter
Notch Filter with high Q easy to realize on breadboard - Electrical Engineering Stack Exchange
2 Meter band. 144 - 146 MHz High Q, Low Loss Band-pass Filter
Essential audio filters guide: How to use high-pass, low-pass, and band-pass filters | Native Instruments Blog
Does Q-Factor matter for low pass and high pass filters? - Electrical Engineering Stack Exchange