Priezor

Priezor is an open-source passive magnetic antenna for electromagnetic listening. It is very sensitive and capable of capturing faint atmospheric events in VLF radio bands. Compared to regular Elektrosluch, it is less directional and focused, and therefore more useful in recording ambient electromagnetic fields, where the overall “sound of the place” is desired.

It is about 30dB (~31.6x) more sensitive than common pickup coils (measured at 1kHz). For recording VLF (“natural radio”) sounds, it will perform best when paired with low-noise microphone preamplifier with at least 70 dB of gain (for example Sound Devices MixPre-3).

How to use Priezor

  1. Make sure that phantom power on your input device is off
  2. Plug your Priezor to the microphone input of your recorder / mixer
  3. Adjust the gain accordingly and listen

Technical specifications

Custom-wound heptagonal magnetic antenna
Frequency response 20 Hz – 90+ kHz
Antenna 333 turns of 0.118mm enamelled copper wire
Loop resistance ~300 Ω
Loop inductance ~50 mH
Cable 1.5m shielded high-flex microphone cable
Connector silver-plated black Neutrik XLR