Got my 1st unit today - Um a noddy question, but what kind of USB cable do Ineed?

1) Does the AM have a resonance, or excess gain at 20kHz? I tried a dozen indoor/outdoor settings, and there is always a band at 20kHz. The spectrum below is inside a quiet room. 2) In most of the indoor, quiet room, recordings, I see a rising thin line in the 30-50kHz range, see the above spectrum, the five panels cover about 20 minutes. Could this be a form of self-noise? 3) The clicking noise, I saw on other posts that this is SD card writing? I only see this occasionally. The image below was from inside a parked car at night - very quiet. Is the suggestion still to get the "Extreme" version of the SD card? Thanks - I love the unit. Keep up the good work - you are making a lot of research possible.

Hi, I understand that you have done some trials with Audiomoth and LoRa in Belize (based on your post in April 2019). May I know if there are any updates? We would like to use the Audiomoth for sensing gunshots, and real-time alerting of rangers via a LoRa network. Thanks a lot!

One of my older units (1.0.0) refuses to work (no files written when I deploy). I have flashed with the latest firmware (1.2.2), but when I try to configure or use the Time app. I get a reading of <3.6 v. The batteries are new, and if I put them in another unit I get a reading of 4.8 v. Any ideas?