Hydrophone Experiments II

I started experimenting with inexpensive DIY hydrophones awhile ago. This update discusses encapsulation, commercial hydrophone elements, and modifying a Primo EM172 capsule for underwater use.

Hydrophone Experiments

An underwater microphone using a common mic capsule and silicone sealant. It has relatively flat frequency response without the resonant “honk” of the piezo disc used in most DIY hydrophones.

Exploring Ultrasound

Experiments with recording ultrasound bat calls using the built-in mics of the Roland R-05 portable recorder.

Alex Rice Piezo Preamplifier

Alex Rice designed a phantom-powered preamplifier for piezo contact mics and hydrophones. It sounds great but his site is offline. I posted his files and made some changes of my own.

VLF Natural Radio Experiments

“Natural Radio” is the low frequency residue of lightning strikes and space weather. After building a simple preamplifier circuit, you can tune it via the mic input of any recorder.