This dual detection model allows you scan all frequencies at once using frequency division then home in on a specific frequency using the heterodyne mode. With stereo headphones, the heterodyne signal comes through the left channel and the frequency division through the right. The rugged D-200 series are all small enough to fit in a pocket and can be operated with one hand.
Heterodyne Heterodyne bat detectors offer immediate identification of bats in the field. You select the ultrasonic frequency range to listen to just like tuning in radio. Heterodyne detectors typically have a headphone socket and line-out socket for recording calls.
Frequency Division Frequency Division detection is a `broadband' method as the entire ultrasonic range audible all the time (in contrast to a Heterodyne detector, which is sensitive only to a limited range of frequencies at each time). Calls are transformed in real time i.e. the calls are heard through the detector at the same time they were emitted by the bat. By listening to the full range of frequencies you won't miss a bat while tuned into the wrong frequency. Frequency Division detectors can be used for sound analysis of recorded calls.
* Type: Heterodyne and retained amplitude frequency division (divide-by-ten)
* Frequency range: 10 - 120kHz (min.)
* Display accuracy: +/- 0.15kHz
* Bandwidth: 8kHz (+/- 4kHz), -6dB
* Battery: 1 x IEC 6LF22 (9V)
* Quiescent current: 23mA typ. including LCD backlight
* Comment switch: Yes
* Size: 119 x 60 x 25mm including knobs
* Weight: 160g including battery
* Outputs: 2 x 3.5mm jacks for headphones and tape recorder