Cell phone in a deco habitat????

[OutlawCaver]

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.

[lonestarfl]

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?
Maybe make an omni directional and a directional version depending on application...or even better, switchable.

[IowaCaveDiver]

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

[OutlawCaver]

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.......

[IowaCaveDiver]

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

[OutlawCaver]

Please don't be impressed. I just make stuff up as I go along.

[John L.]

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!