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Joe, This system was designed to be as simple as it could be so that those not rehearsed in electronics would have a chance to complete a fully functioning set up. This is simply broadband voice communications. Think of this as am 8 ohm speaker that works underwater! It is not known for certain, but divers should be able to hear these underwater communications without it causing serious eardrum injuries. This might come in real handy should you be stuck on the bottom and in need of help.This is an area that will be tested in Michigan this comming Spring. In Spring, two submarines with two seperate and fully functional systems will determine the maximum range of this simple system. Also to be observed will be the clarity of this type of communications as well as the ease of use as it pertains to these consoles. (The newest set up will use a cb styled handset to change from passive or listen mode to active or transmit. This will then transit back to listen mode once the thumb switch is released. The first produced units use a simple two pole double throw toggle switch to perform this feat that might require too much operator interface) With the aid of an extension cable of up to ten feet, this console, once turned on and the levels of amplification set to a desired level, could be placed anywhere out of the way with only this hand mike to operate it. The battery has been shifted to an externally located one so could be quite large for longer usages and again could be located out of the way. The latest modification makes use of two passive hydrophones (one on each side of the boat) with but a single transmitter. When transmissions are being conducted, this second hydrophone is shifted to a "summing" jack and the two hydrophones are summed or added together so as not to lose any geopgraphical area of coverage. In doing this in this way, it also ensures that both incomming hydrophone signals are removed during periods of actual voice transmissions. This is beiing done to avoid damage to these amplifier electronics do to overloading. Although not verified by in-water testing, I feel that with two hydrophones, one might be able to determine the rough location of detected sonar contacts by simply listening to two simularly mounted speakers. The hydrophone on the opposite side of the boat from the contact should be quieter. The air within the submarine should reflect sound that normally would have made it to the hydrophone on the other side. (line of sight) For those braving the ocean itself as a submarine environment, these hydrophones should be very effective at both hearing boat traffic and biologics as well. Sounds great but what expense are we talking about? To have a complete system with two hydrophones, a single voice transmitter, cb styled handset, and the fully functional console for both transmitting and recieving would cost slightly less than $200.00! Each vessel that wished to participate in cross communications would need both a transmitter (This could be a simple singing machine that is battery operated) and a way of listening (a single hydrophone with a small battery operated amplifier (could be a baby monitor from Radio Shack) The schematics have thus far not been presented as modifications are still being refined and in-water testing could expose items that could be simplified. Once these results are in and the performance evaluations are completed and reviewed, a full set of schematics will be made available to those who wish to dive in. David Bartsch From: joeperkel@hotmail.com To: personal_submersibles@psubs.org Subject: RE: [PSUBS-MAILIST] sound transducers Date: Fri, 14 Nov 2008 21:55:29 +0000 David, Not having any field experiences and out of curiosity, this brings to mind a question regarding underwater voice transmission in general. I've seen voice comm between Alvin and Atlantis, Calypso and the saucers, habitats,...etc. Is this voice comm severely scrambled (distorted by the seawater), and then reprocessed by the receiving equipment? Or, put another way, if I swim between divers with voice comm equipment, could I hear the conversation like I do prop noises? Joe From: dbartsch2236@hotmail.com To: personal_submersibles@psubs.org Subject: [PSUBS-MAILIST] sound transducers Date: Fri, 14 Nov 2008 15:36:04 -0500 To all: The transducer for solids from which can be made the broadband voice transmitters are available on e-bay under "underwater speaker" at this time. These are selling for $26.95 but shipping is being provided. This is not a bad price if you were concidering delving into this area of study. With a singing machine that is battery operated, a voice transmitter can be made from the use of this. (It still needs to be imbedded in molding plastic to survive deep depths.) And you will still need a means of hearing the return responce. It sure would be great to talk back and forth between two submerged submarines or to your support boat without having to surface first. David Bartsch Windows Live Hotmail now works up to 70% faster. Sign up today. Get 5 GB of storage with Windows Live Hotmail. Sign up today. |