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:idea: I was just curious. Has anyone ever tried to take a cell phone into a dry deco habitat (via dry box) and tried to use it? I wonder if it would work. My guess is most likely no.
Or what about those 2 mile - walkie talkies from radio shack or walmart you can get? Would those work for surface folks?
Just thinking thoughts I've never thunk before, on a boring Monday morning.
i dont know what kinda reception you would get through 20+ feet of water
Jay and I found an "underwater" cellphone at WW one dive. It did not get good reception at 20 ft there... :wink:Quote:
Originally Posted by Titen
Nokia has a cellphone that works while submerged up to 10 feet.
haha i remember that, i also remember straping it to my O2 bottle at Ginnie during the social last year :-D i wonder if anyone ever saw itQuote:
Originally Posted by Tegg
Ohhhh!!! That's just freakin' Great!!!
Now when I'm decoing in the Eye I gotta listen to some Jackass yack on his cellphone there too!!! Can't you people just use those things in traffic, movie theatres, church sermons, Wedding and/or Funeral ceremonies, or in the Library just like everyone else? You have to ruin the peace underwater too??!!! #$*&@#*&%!!!
I guess I will start packing a speargun during my Cave dives after all. I've been looking for a reason. Spiiift...............Twang!!! Right through the "Call Button" :drowning :smt063
You have been warned!!
My cell doesnt even get reception on the surface.
I gotta have two one Cingular and one Sprint. Cingular works great in Luraville and not at Chaz, the Sprint works at Chaz but Nothing in Luraville.
I have sprint but I think my phone is jest crap.
If a bird flies between me and a tower it drops the call.
My cingular phone works great in both...?Quote:
Originally Posted by curtschu
Some folks have had some success with getting radio signals out of a cave during a mock rescue using the com wire. Give it a few wraps around the antenna. You might post a question on the NSS discussion board under electronics.
For a dry deco habitat though I would think you could just run a wire and use field phones, especially since it would be such a short distance. Of course you would need someone on the surface to relay your pizza order.
Yes, Sprint has the clearest call you'll ever drop....Quote:
Originally Posted by Gibby
I have Sprint and get reasonable signal on the I-10 corridor and approx 1 mile either side of it, in Luraville and HS it goes into roaming, sometimes digital (good) sometimes analog (crap).
I really doubt you'd get good reception in a habitat though, my understanding is that signal is line of sight on these gizmos...
Dive safe,
Celia
Most cell phones work in the same frequency range as GPS, more or less. Penetration of fresh water is on the order of inches, as it's a conductive medium, and conductive media attenuate RF energy.
You might be able to either install an antenna above the phone with a waterproof coax feedline to the habitat, or even a passive repeater system (coax with resonant antennas on each end).
Drew
-.- --- ....- -- .-
KO4MA?Quote:
Originally Posted by Limestone Cowboy
OMG - What are you doing!?! Don't give them any ideas!!!Quote:
Originally Posted by Limestone Cowboy
:-D
Whatcha gonna do?
Order a pizza?
I think that a deco habitat should be treated as though it was a Chamber. These items are not allowed in a chamber because they could be a source of ignition. Unless you have a cell or two-way that is sealed I wouldn’t trust it in a pressurized environment with me.
But on Mythbusters, Jamie and Adam declared the cell phone ignition source idea as busted .
http://www.worldtribeweb.com/uploads/jamie.jpg
Nah, I was thinkin of dialing one of them 1-900-numbers. :smt055Quote:
Originally Posted by Gibby
Many, many years ago my father worked out a way to use a CB radio about 20' under water. He ran an antenna up a rope line to the dive flag. He had several interesting coversations <g>
A cell phone or any other electromagnetic, EM transceiver will work underwater provided you remote the antenna to the surface. You get into issues like getting the standing wave ratio, SWR correct to maximize antenna gain. As for using it underwater, the EM energy is absorbed in a much shorter range than in air. There would also be a refraction issue with the surface.
On yet another note, I am designing a portable, covert cell phone jammer to be used at your favorite ball game, theater, restaurant, etc. Imagine your joy watching the frustration as fellow patrons kick, scream and shout at their cell phone providers while you flip on the handy dandy RamaJama. OH BUT THEN there is the liability issue that little Johnny's baby sitter can't reach someone to inform them of the catostrophic event that he won't go to sleep. Or the heart surgeon that has to be reached 24/7 (right) to dictate to a nurse his commands. I would be more concerned about lost booty calls than anything else.
I knew all those years of EE school would come in handy.
When can I get one?Quote:
Originally Posted by OutlawCaver
Maybe make an omni directional and a directional version depending on application...or even better, switchable.
catching up on posts....
lets try two tin cans and a long piece of cave line.... think it would work if you cleared the submerged can of water? cheaper than a cell phone and you don't have worry about minutes.
-Matt
Due to the density of water being much higher than air, there would be a significant acoustic impedance mismatch. Therefore, the longitudinal waves in the string acting as the propagation medium and the transverse motion at the end of the can acting as the diaphram would be severely attentuated. The longitudinal wave suffering from viscous and heat conduction losses. The end result would be no acoustic energy level appreciable enough to hear. A wire rope or a large diameter stiff poly rope may have better results. A steel rod would probably work the best. Just like using a screwdriver to listen to engine sounds like bearing wear or valves tapping.
If both you and your buddy both hold your breath and speak into your regulators you can just about understand each other perfectly.
I just love this techincal talk.......
wow.. i'm impressed by your scientific knowledge of this subject, unfortunatly I have not an idea of what you are taling about, but I'm assuming it basically means that it wouldn't work. Seems like we could have all sorts of fun trying out these varieties of communiction... or we could just dive solo and talk to ourselves.
-Matt
Please don't be impressed. I just make stuff up as I go along.
If you can't get the phones to work, theres always laminated centerfold pics you can put in your wetnotes. This also helps cut down on a condom cath falling off due to cold water shrinkage! :D