Anyone with electronics background?

[Mikemonster]

I would like to customise a detector to work underwater being towed slowly behind a boat.
This would mean lengthen the detector head wires 60 foot and boosting the audible. I'd like to use two detectors mounted 10-12 feet apart on a sled.
Is this possible? Can someone build this for me?
If successful they could be marketed.

 

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[rcasi44]

It's already been done. There is no way a hobby type detector could be modified for the task. Rob

 

[Sandman]

Correct! Something of this sort is available. To use two only 12 feet apart and they are VLF's of the same freq. they would scream at you. Also you would have to get the coil very close to the bottom where you have no means of ground balancing.

 

[yanis]

Get your self a pulse star II with 2 sq. meter coil ask the dealer to provide you with an extension cord and you are in busines, Don't forget to put some starofoam on the cornes to stabilize the coil on the surface, It works.
Regards
Yanis

 

[PlanetExpress]

I just looked at the Pulse Star II and see that it is mostly for locating large objects. Is there a way to get an "extension cord" for the detectors that can be used for smaller objects, say... a small gold coin on the bottom?

I am quite interested in this topic that the original poster was asking about. I'm building something like what he's talking about right now (side scan sonar), and wish to integrate a detector into it, but want to do it on a budget, just like the home made side scan.

 

[99thpercentile]

These already exist in the unexploded ordnance (UXO) community for detection in shallow water. I have used a Geonics EM61-MK2 with a waterproof coil and cables to look for UXO in 10 meters of water in Puerto Rico. There are some systems under development by AETC, Inc that are funded by the Environmental Security Technology Certification Program (ESTCP) which are towable. They have a 3 meter wide by 1 meter transmit coil and an array of 6 1 meter by 1 meter receive coils. Also there are magnetometers in the center of each receive coil. The unit can tell its depth as well as the water depth and be programmed to stay at a prescribed depth or height above the bottom.

Ryan North