milo@ndmath.UUCP (Greg Corson) (01/14/87)
Does anyone have any idea where I might be able to get a waterproof ultrasonic transducer? The type used in fish-finders might do but I would prefer something smaller if possible. I might also be able to use an underwater speaker/microphone (hydrophone?) that operates in the audio spectrum. The application will be transmitting computer data through water sonicly, ultrasonic components would be prefered because of the higher information bandwidth possible due to the high frequency carrier. I have dug through a lot of surplus catalogs but have had no luck so far, if you know where I could get something like this I would be very grateful Greg Corson ...seismo!iuvax!kangaro!milo P.S. For communications use I obviously need 2 of these things...so one of a kind components won't be of any use.
jeffr@sri-spam.istc.sri.com (Jeff Rininger) (01/15/87)
In article <172@ndmath.UUCP> milo@ndmath.UUCP (Greg Corson) writes: >Does anyone have any idea where I might be able to get a waterproof ultrasonic >transducer? [. . .] Greg, this is total speculation, but a piezo tweeter (Motorola makes one) might do the trick. I know they work to at least 40 kHz, and I used one outside in my garden (ultrasonic bug repellent experiments) for a year or so. It seems to have survived the rainy season, so perhaps it is waterproof. The cost is low (about $5.00) to be worth a try, anyway ! Good luck !
dje@datacube.UUCP (01/16/87)
Depth Sounders for boats use waterproof transducers. They use 100-200KHz fixed frequency pulses. Get a marine catalog, find a company, and order a replacement transducer. Should be under $40.00. Dave Erickson ------------------------ Datacube Inc. 4 Dearborn Rd. Peabody, Ma 01960 617-535-6644 ------------------------ ihnp4!datacube!dje
brian@sdcsvax.UUCP (01/17/87)
In article <172@ndmath.UUCP> milo@ndmath.UUCP (Greg Corson) writes: >Does anyone have any idea where I might be able to get a waterproof ultrasonic >transducer? The type used in fish-finders might do but I would prefer >something smaller if possible. .... Ultrasonic transducers used to be available quite cheaply as replacement parts for TV remote controls - check with a local TV shop. You can make them waterproof by putting them into thin rubber sheaths (like condoms) and sealing the cable entry point with RTV or similar material. If you are worried about loss in the air-rubber-water interface, you could fill the sheath with light mineral oil. The cashier at the drugstore probably isn't even going to give you funny looks these days.... Brian Kantor UC San Diego
ems@prls.UUCP (Gordon Vickers) (01/19/87)
I've been ignoring this subject but decided to read a couple of messages
today. Hope my suggestion hasn't been 'aired' yet.
Edmund Scientific used to carry waterproof transducers. It's been a few
years since I've seen one of thier catalogues, but they may still carry
them.
------------- fold, spindle, mutilate at will ------(it's your CRT) ----
Gordon P. Vickers, (408) 991-5370,
Signetics Corp., PO Box 3409, M/S 69, Sunnyvale, Ca 94086
{allegra,decvax,ihnp4}!philabs!prls!ems
or
{ucbvax,decwrl,ihnp4,allegra}!amdcad!amdimage!prls!emsjra@jc3b21.UUCP (Jay R. Ashworth) (01/21/87)
In article <9823@sri-spam.istc.sri.com>, jeffr@sri-spam.UUCP writes: > In article <172@ndmath.UUCP> milo@ndmath.UUCP (Greg Corson) writes: >> [ Discussion follows here concerning the problems involved in finding >> a waterproof ultrasonic transducer, and a suggestion for using a >> piezo tweeter instead. ] I missed the lead article here, so forgive me if this goes astray (PS: No, I'm not really a Prince fan...)... If you are looking for a water *proof* (as opposed to, say, water *resistant*) ultrasonic transducer, you might want to consider going to a marine supply house or wholesaler, and checking on the price of a depth sounder head. Of course, as we all know, the 3 most expensive words in the English language are "marine" and "mil-spec", but, if you are, for example, building your own depth sounder, you might want to spend the money. It seems to be a better alternative, in the long run, to having your boat sink... -- jra (P.S. English teachers - please forgive me my parentheticals...)
charlie@oakhill.UUCP (Charlie Thompson) (01/22/87)
Try "Radarsonics", Inc Their Address is 1190 North Grove Anaheim (home of Disneyland), CA 92806 Phone (714) 630-7288 Telex 183-511 CSMA Heathkit and many other 'depth sounder' manufacturers use their products. They operate from 38 KHz to 200 KHz and there are many models available. Radarsonics will be happy to send you a catalog.. call or write them. ---Charlie Thompson, Moto DSP Operations