Thanks for the offer John.I don't anticipate any problems, unless the big one happens, and if it does, Persistence will be both too heavy and too deep for much help.
The plan is to do the test on Saturday the tenth. We'll be launching out of Watkins and towing up about four miles. We had planned to launch at Saverne, on the lower west side, but the lake is down about a foot and a half and it's now to shallow to launch there. If you on the water, just look for a stationary boat over 550 feet of water with a few people biting their nails and pacing around the deck. That will be us!
Several times I thought of stopping by your Dads on the way back from Seneca but just didn't yet.
I don't think we need to race. Lake Diver has been up there, on and off, for what, twenty years now? I'd hate to loose to the "old girl of the lake." ;-)
Dan H.----- Original Message ----- From: "john" <mongo14904@yahoo.com>
To: <personal_submersibles@psubs.org> Sent: Friday, September 02, 2005 5:32 AM Subject: Re: [PSUBS-MAILIST] Underwater Communication
Dan When you are at seneca lake doing you test if you have any problems. Lake diver is here in ny now (elmira) and can be there to help in less than 2-3 hr also id love to come up when you are here and check out "Persistence." When are you going to be there heck we could bring lake diver along and have a race Take care john --- "Dan H." <jmachine@adelphia.net> wrote:For a quick up date on my sub "Persistence." I revamped my thruster controls to what they should have been in the first place. I had relatively light relays controlling the motors. After many hours of use they started sticking, both on and off. Pretty scary when you're spinning around in a marina next to docked hundred thousand dollar boats. I was going to switch to solid state but decided to stick with mechanical relays, only use heavier ones. It's fine now. I've been diving the sub in relatively shallow water for a year. Finally, I'm going to do a deep water test. It's time to get out-a-da baby pool and in-ta-da the big pond. In a week and a half we're supposed to take Persistence up to Seneca Lake in New York State and do an unmanned deep water test. It's going to be weighted thirty pounds positive to go to 550 feet on a line. After sitting on the bottom for an hour, a second smaller line is pulled to release sixty pounds of weight and Persistence now thirty pounds negative, will come back to the surface......if all goes as planned. If it doesn't, well, we won't think about that right now. Ah yes, Underwater communication! I have a request of you electronic types. I have been researching several methods of communication between my sub and the surface. There are three methods I came up with. One is to have a radio transceiver, VHF or CB type, in the sub and a coax cable to the surface with an antenna on a float. It's relatively cheap but there is the drawback of the cable dangling in the water to get caught in a thruster. Also, I've been told that after running through 350 feet of cable there won't be much of a signal radiating from the antenna. Another drawback is coax cable is big and bulky to store on a reel on the back of a small sub. Method two is almost the same as method one except with an intercom in the sub and a twisted pair of very small wires going to the surface. The unit is also cheap and it has the advantage of very small wires going to a surface float so 350 feet of cable will store easily, but to communicate, a surface boat has to actually get to the float and plug in their half of the intercom. Also, there is still the chance to get the wire wrapped up in a thruster. Now for the big bucks! The proper way to do it is to have an acoustic type underwater telephone. I have tried to transmit from the sub with a walkie talkie and it's good until you get about two feet deep. The radio frequency electrical signal gets absorbed into the water and that's the end of the contact. An acoustic telephone uses high frequency sound waves instead of electromagnetic waves as a carrier. Since sound transmits through water quite well, they work fine. I know there are commercial systems out there to be purchased, but for a personal sub, they're way high in price. I was wondering if anyone knows of a system for communicating that might be in a P-sub price range or, is there anyone out there that has the know how to design a system that can be built by someone with a little bit of electronic knowledge and a soldering iron. Captain Kittredge had an acoustic system designed and they built a few of them. I understand they worked reasonably well but that was thirty years ago. With the advances in electronics, most of the components he used could probably be replaced with a few IC's. Does anyone know of a reasonable priced system out there or, is anyone knowledgeable in this area and willing to take on the challenge of designing something. I'll do the building but I just don't know what to build. Thanks for listening, Dan H.__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. 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************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG PO Box 311 Weare, NH 03281 603-529-1100 ************************************************************************ ************************************************************************ ************************************************************************