I was looking into the latest and greatest microphones, ultrasound microphones and detecting ultrasound in general more real time spectral analysis since I was thinking about modifying the Mini-3 Bat Detector to perform a more automated sweep versus just turning the variable capacitor. Well, I found this interesting video that's inspired me to add an antenna connector onto the Mini-3 Bat Detector or just invest in one of the Franzis systems this gentleman is using in the video: In regards to sonic range recording and maybe getting into the ultrasonic range... there is this build that has some great info regarding the most cost effective lowest noise mic on the market, the Rode NT1-A Studio mic: If you read into the above videos description link, the authors note the amplifier might be good above 100kHz also. Here is the screenshot from the above video of the schematic noted used: See here for above video reference: https://sound-au.com/project66.htm In regar