Please note that not all tape recorders can be used for this. It is required that the recorder can be left
with the "RECORD" button permanently activated and that it is possible to connect the output of the
relay in series with the recorder’s batteries or power supply. Please note that the maximum ratings
(current and voltage) of the relay must not be exceeded! For information on the maximum ratings
please refer to the specifications for the relay!
Please also make sure that the recorder starts quickly enough. Most recorders require at least one
second to start recording.
High-speed replay
When the NORMAL/TE
→
HET switch is in the TE
→
HET position, the signal in the time expansion
memory will be replayed at its original rate, as described above. The signal from the time expansion
system is also available at the RELAY OUTPUT connector. As opposed to the TE signal at the TAPE
jack, this output is not lowpass filtered. So, if you have access to an ultrasonic transducer
(“loudspeaker”), you can use this output to replay the captured sequence in its original shape. The
impedance of any device connected to this output should be at least 500 ohms.
The “Relay Output” Connector (top view)
1 and 2 – relay output (if polarized, 1 = positive, 2 = negative)
3 and 4 – signal output (3 = signal, 4 = ground)
5 – polarizing hole for the connector
NOTE: If you wish to connect equipment other than Pettersson Elektronik’s to this connector, please
first contact us for instructions. Please also be careful not to let metal objects enter the case of the
detector through the relay output connector opening, since this may damage the detector.
INPUT GAIN CONTROL
In order to avoid overloading the input amplifier, the D240x has an overload indicator and an
adjustable input gain control. If the signal is overloaded, spurious harmonics will be created. Such a
signal should of course not be used for analysis. If the OVERLOAD indicator flashes frequently, you
should set the GAIN switch to LOW. The actual gain in the LOW position is determined by the setting
of the GAIN control. To adjust this, use a small screwdriver or similar (the control is located about 5
mm below the front panel). Usually, this is not necessary to do very often, you will probably find a
suitable setting and you will then only use the switch to change the input sensitivity when required.
OUTPUTS
The two 3.5 mm sockets are used to connect a set of headphones or a tape recorder. The TAPE output
is not affected by the setting of the volume control or the HET/TIME EXP switch. When the COM
switch is pressed, the time expansion output signal is temporarily replaced by the amplified
microphone signal, enabling the recording of spoken comments on the tape.
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2
3
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