Pettersson D200

Available, usually ships 1-2 business days

This quality heterodyne bat detector features a large, very accurate backlit LCD displaying the center of the tuned frequency in kHz. The detector in real time plays any ultrasound that is approximately 4 kHz above and below the tuned frequency.This method works by frequency subtraction and only a very narrow part of the spectrum is scanned at any given time, so a tremendous amount information is not detected. A headphone port allows for private listening. 

Heterodynes produce analog output that is not used for detailed computer analysis. However, many people are able to discern different species with practice in areas where there is little overlap in call frequencies. With some experience and knowledge of the local species, you will be able to group calls by genus, which is suitable for interpreters doing bat walks, or bat enthusiasts looking for a low cost acoustic detector. Tone qualities of the output change if the bat is calling above or below the present frequency of the detector. This enables users listening in real time to rapidly "tune into" the bat as it flies by and get a good estimate of the bat's dominant frequency, the basis for species identification.