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Switches are arranged on the rear so that the all important start/stop recording button is naturally under your finger when holding the detector during active monitoring.

The D240x features an auto-triggering setting with an adjustable threshold to send more calls and less noise to your recorder when used passively.


The front of the D240x shows the center of the tuned frequency band when in heterodyne mode. This readout has no bearing when recording in TE which is always full spectrum. It records TE constantly even when listening to the HET output, enabling you to wait for a good bat pass before triggering a TE save so you avoid lesser quality calls.


Pettersson D240x
ne and Full Spectrum Time Expansion Bat Detector

The bat detectors from Pettersson Elektronik are high quality instruments, designed in close cooperation with leading bat workers for optimum performance in full spectrum recordings.

Two detectors in one! Select between HET or TE audio technology at the flip of a switch. A backlit, digital display shows tuned HET frequency. This is used when actively monitoring bat activity so you can hear in real time when the detector is receiving a strong bat call.

Listen to the HET output in real-time for the ideal bat pass while the D240x simultaneously records the full spectrum (10-120 kHz) sound. When a suitable, desired bat has just passed by and the HET clicks are starting to fade, single-handedly stop the full spectrum recording with a button push on the back of the D240x. The D240x will continually replay the full spectrum (and now time expanded) call which can be off-loaded to a separate recording device such as the H2 Zoom or into a laptop running SonoBat or Batsound.

Flip the master output switch to TIMEEXP to listen to your newly recorded bat pass in 10x time expansion and the high quality tonal qualities that only full spectrum recordings can capture.

Pettersson D240x Specifications:

  • Sampling frequency: 304 kHz
  • Frequency range:10 - 120 kHz
  • Small size: 119x60x25mm with built in loudspeaker.
  • Manual and level-sensitive automatic triggering.
  • Frequency-selective trigger in the level-sensitive mode allows user to exclude certain frequency ranges.
  • Record various lengths of TE calls to an on-board memory chip: 0.1s, 1.7s (recommended for passive monitoring), and 3.4s (recommended for active monitoring).
  • 0.1s in auto trigger mode will allow you to hear the tonal qualities of the bat pulses in real time without the "dead air" in-between pulses.
  • Attach a digital recorder for a compact, reliable passive recording package or to enable voice notes during active monitoring, without a computer, if desired.
  • Capable of automatically capturing bat calls and, using a separate control box, off-load TE calls to a connected recorder.
  • The TE signal stored in the detector memory can be replayed at its original rate through the HET system.
  • Power: (1) 9-V alkaline battery; operates for 12-16 hours
  • Output: (1) audio line out, (1) headphone port Audio cable is a standard stereo and easily found at any electronics department



Pettersson D240x: $995.00 USD

Price includes (1) D240x, instruction manual, (1) 3' audio cable with left channel disabled.

Shipping charge will be calculated during checkout. International shipping will be quoted after you place your order.


Spare audio cables- left channel disabled for use with the D240x

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Pettersson D240x
Heterodyne and Full Spectrum Time Expansion Bat Detector


More info?
Download a PDF Brochure on the Pettersson D240x

  • Used at all BCM and BCI workshops for quickly recording full spectrum voucher calls into laptops
  • Extremely high quality sound; the SonoBat classifier was built using this device
  • Superb quality control & consistency between units
  • Time tested and dependable; returns for service are practically non-existant.

Selectively record a bat pass in 4 easy steps...

1. Prepare for active monitoring

On the front, ensure the switches are set to NORMAL, HET, and HIGH. Tune to about 40 kHz.

On the back, ensure switches are set to MAN and 3.4 seconds. TRIGGER switches are for automatic recording and don't matter in MAN mode.



2. Start a recording

Hold the D240x so that your index finger rests on the START/STOP button (SSB). Press the SSB so that the red LED on the front is lit-- you are now recording in full spectrum to a 3.4 second "loop buffer."

Point the microphone skyward and start "fishing" for bats, while listening to the heterodyne output in real time.


3. Stop a recording & listen to FS

After you hear a "strong" bat pass start to fade away, press the SSB to stop the recording. The red LED will go out. Don't press the SSB again or the buffer will be deleted!

Ready to hear your recording in full spectrum slowed down 10-times (time expanded)? On the front, switch to TIME EXP and the recording will already be playing in a loop.

Tip: If you plug in headphones, you'll always hear the HET signal live in your left ear, and the TE buffer playback in your right ear. If you hear a "better" bat on the HET you can instantly record it in full spectrum by pressing the SSB again!


The D240x TE output can be saved without a laptop using a digital recorder such as the Zoom H2 recorder. Using the SonoBat AutoParser utility these calls are time stamped and waiting for further analysis.


View the guide on how to set up your D240x and a Zoom H2 for passive monitoring.

4. Download to SonoBat

Connect the audio cable from the TAPE jack to the audio-in port on your laptop. Select "Record" in SonoBat to enter the recording utility.

Enter a descriptive text file for the recording session and a "file name start," then press the record button. The bat pulses will appear in the oscillogram. The D240x endlessly replays the recording, and often a "thunk" will sound out when the SSB was pressed. This is how you can identify the start of the recording. Or just let it play for awhile until you see the pulse pattern repeat.

Press stop and select the crop tool to edit just the section you want (ideally just after the "thunk"), then press "save and view [return]" to bring your recording into a high resolution SonoBat view.


Bat Conservation and Management, Inc. Carlisle, Pennsylvania (717) 241-ABAT

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