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The high-pass (HP) filter attenuates low-frequency signals and should usually be used (ON).
It starts cutting off at around 20 kHz. To record signals with a frequency below ca. 15 kHz,
set the filter to OFF.
The trigger sensitivity (T SENS in the User Profiles menu) - not to be confused with the
trigger level – determines the requirements for the duration of the signal in order to trigger the
detector. To make the detector start recording for any signal duration, set the trigger
sensitivity to VERY HIGH. If, in a certain recording location, many non-bat recordings (wind
noise, crickets, rain etc.) are obtained, set the trigger sensitivity lower. That way, many of the
undesired recordings will be avoided, while most of the bat calls will still be captured. The
lower settings of the trigger sensitivity makes the unit less sensitive to signals with longer
duration. Changing the trigger level will also affect the number of recordings. The trigger
level is set in the Recording settings menu.
The trigger source is normally the sound from the microphone. The external trigger signal is
activated through a link in the plug connected to the External Trig input jack.
RECORDING SETTINGS
The parameters in the recording settings menu are:
Input gain (volume)
Trigger level
Minimum time interval to the next recording
The highlighted parameter is changed with the left/right arrow keys. To move to the next
parameter, press the down arrow key. To accept and save the settings, press ENTER and the
detector will return to the main screen.
The input gain should be adjusted to keep the recording level (as shown on the dB indicator)
below the limit.
The trigger level should be adjusted to make the detector trigger (start recording) at the
desired level. To aid this adjustment, the text “*” flashes during the setup process each time
the detector is triggered.
The (minimum) time interval between successive recordings is determined by the Interval
parameter. It takes the values 0, 5, 10, 15,….., 55, 60 seconds. Using a value greater than 0
means that at least the chosen time interval will have to elapse before the next recording is
made, thus avoiding that the CF cards are filled excessively fast in situations with high sound
activity. The actual minimum time between recordings may differ somewhat from the entered
value, since there are variations in the time it takes to open and close files depending on the
number of files on the CF card.
