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M38 Hydrophone Header
M38 Wide Band Omni-directional HydrophoneThe M38 Hydrophone comes standard with a male 8-pin micro bulkhead connector from Subconn.

Download each products’ specification sheet for more information or contact GeoSpectrum directly with your inquiries.


M38 Omni-Directional Hydrophone (Connector Cap Off)The M38-100 is a wide-band omni-directional transducer that can be used as both a hydrophone and projector up to 400 kHz. The hydrophone is not suitable for long term marine deployment.

icon_PDFDownload the M38-100 Hydrophone Specification Sheet


M38 Omni-Directional Hydrophone Side ViewThe M38 is also available as the M38-200, a wide-band omni-directional hydrophone that operates up to 400 kHz. The hydrophone is designed as a reference hydrophone. It comes with a pre-amplified output of 0 to 35 dB (selectable on order) with current or voltage signalling.

icon_PDFDownload the M38-200 Hydrophone Specification Sheet

M18 Characteristics
Nominal Voltage Sensitivity (without preamp) -207 dBV re 1 µPa @ 20°C
Frequency Range 1 Hz to 400 kHz
Capacitance 0.4 nF
TVR at Resonance 140 dB re 1µPa/V @ 1 m
Depth Rating 1000 m
Storage and Operating Temperatures -40 to +70°C
Size 7.3” length, 1.3” max OD
Labelling Calibration parameters, serial number, date
Connector MCBH-8M
Preamp signalling Current or voltage (selectable on order)
Gain 0 – 35 dB (selectable on order)
Input Voltage 6.8 VDC nominal
4.5 – 30 VDC operating range
Band Pass 20 Hz HPF, no LPF installed (unless otherwise specified)
IRN <30 nV/√Hz @10 Hz
<4 nV/√Hz @1 kHz
Current Draw 1.3 mA (at 6.8 VDC)
4.2 mA with current signalling preamp

M38 Hydrophone Frequency Response Chart

M38 Hydrophone Frequency Response (w/o Pre-amp)

M38 Hydrophone Frequency vs TVR Chart

M38 Hydrophone Frequency vs. TVR

Please contact us for further details or to discuss your specific needs.

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