ELF Development Kit- RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues - primarily having to spend time purging garbage posts from the board. At some point I might start the RF Cafe Forums again if the phpBB software gets better at filtering spam.

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em101
Post subject: ELF Development Kit Posted: Mon Feb 26, 2007 10:18 pm

Lieutenant

Joined: Mon Feb 12, 2007 11:38 am
Posts: 2
I am trying to learn the design and functionality of extremely low frequency EM communication system. Is there any development kit I can use to test the functionally of extremely low frequency radio devices, where I can make both the devices talk to each other. The reason I need to develop a device at extremely low frequency (1 to 30 Hz) is because the medium of propagation has an extremely high dielectric constant.

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fred47
Post subject: ELFPosted: Tue Feb 27, 2007 12:16 am

General

Joined: Wed Feb 22, 2006 3:51 pm
Posts: 104
Hi!
The US Navy uses ELF to communicate with submarines. The antenna takes up hundreds of square miles in either Michigan or Wisconsin (I don't remember which right now), and is still appallingly inefficient by HF standards. That means it runs high power.

So I don't think you'll find a "development kit" with an antenna - a very critical piece! And the electric bill alone on high power...

(Water has a dielectric constant of about 80 - but dissolved salt makes it very lossy indeed...)

-Fred

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em101
Post subject: Posted: Tue Feb 27, 2007 12:41 am

Lieutenant

Joined: Mon Feb 12, 2007 11:38 am
Posts: 2
What EM system do you recommend I use to communicate through 1 meter of salt water. A system for which I can procure a development kit!
Thanks

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fred47
Post subject: ELFPosted: Wed Feb 28, 2007 3:35 am

General

Joined: Wed Feb 22, 2006 3:51 pm
Posts: 104
Hi!
In a previous part of my career, I worked as an applications engineer for a semiconductor company. One thing I learned is that it costs a significant amount of money to design, fab, assemble, and document a "Development Kit".

That means that companies only create development kits when they see the possibility of the necessary minimum volume of sales for the profit to more than cover the cost of a development kit.

Almost no one uses ELF frequencies that you mention.
---------------
That's why companies hire design engineers - people who can go from ideas to implementations, because they know how to do it. They don't have to have a canned kit.

Universities charge lots of money for tuition for an engineering/science degree, and any degree take lots of time - and people sign up anyway!

That's because no one pays you very well just to solve already-solved problems.

If you want to "do it yourself", MIT offers their "Open CourseWare" free online.

Good Luck!
Fred

Posted 11/12/2012