RE: [PSUBS-MAILIST] Undersea communications & retractable buoy

[Alex <spm2@nomad.ignorelist.com>]

I was thinking: You know there are the hydrophones that work quite well for
communicating. I was just reading about them working to 500ft depth, but I
suppose with a lot of background noise and stuff it could be a problem.

What if, you were to use amplitude modulated ultrasound to communicate? You
could have a 50khz carrier and that would eliminate the interference problem!

Also, how well do regular radios work for this purpose? How well would the 160m
(1.9MHz) HAM band work for this? If you were to bring a pocket AM radio down in
the sub with you and have it inside the transparent dome how far down could you
go and have it still work? You know those "atomic clocks" set themselves by
picking up the 60khz signal from Colorado I think it is, how far under could
you use one of those?

The military uses something like 15khz to transmit globally to the
their submerged submarines.

Alex

On 30-Oct-2009 Jay K. Jeffries wrote:
> Frank,
> 
> Thanks for grounding me.  We need some way to communicate with the subs
> underwater in Ft. Pierce.  David's unit might work but have to be concerned
> with the directionality of the unit.  How do these units work when they are
> not pointed directly at each other?  Topside will not know exactly where a
> sub is to point their unit at the boat and there may be more than one unit
> trying to communicate at a time to confuse things.  I can tell you from
> diving in the area previously, without boat traffic, there is quite a bit of
> background noise.  Two units need to be tested in the shallow waters off of
> southern Florida real soon to see if they are even feasible for the 2010
> Conference.
> 
> R/Jay
> 
>  
> 
> From: owner-personal_submersibles@psubs.org
> [mailto:owner-personal_submersibles@psubs.org] On Behalf Of
> ShellyDalg@aol.com
> Sent: Thursday, October 29, 2009 8:45 PM
> To: personal_submersibles@psubs.org
> Subject: Re: [PSUBS-MAILIST] retractable buoy
> 
>  
> 
> Good thoughts Jay. For a little sub to sub talk at a sub rodeo it might
> work, but depending on it in a real life emergency is........well, it's just
> not there yet.
> 
> Frank D.
> 

-- 
Mailed with XFmail on 29-Oct-2009.
God saved Noah, but Noah had to build an ark!



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