Building a receiver for 518 kHz...is there a kit?

[N5WPG]

Greeting all!

Can anyone tell me if there is an inexpensive kit I may build to recieve 518 kHz?
This is the frequency for Navtex messages.

I am a student here at Maine Maritime Academy, and think it would be a great way to not only practice radio (home brew?) building skills, but it would also offer the opportunity to have equipment that could recieve Navtex messages towards credit for my Marine Communications class. This is one of the STCW-required courses for both, a degree in Marine Transportation Operations as well as preparing to sit for the U.S. Coast Guard 3rd Mate License.

Any help you may be able to offer is very welcomed.

Thank you kindly in advance. :-)

Ralph M Bohm/N5WPG
Maine Maritime Academy Suite 102
Castine, Maine 04420

[kl7aj]

Greetings!

Many moons ago, there was a project in Popular Electronics I believe...a direct conversion VLF receiver that used a 555 timer chip as the local oscillator! Very clever, very cheap...and it worked! I pretty much remember the circuit, other than the actual values. I think you'd be pretty happy with it, expecially since it would be a local station for you on the east coast! I'll see if I can dredge the thing out of my cranial recesses and draw you up a diagram.

Eric

P.S. If you want to be a little more sophisticated, you can build an upconverter that will feed a general coverage receiver. Or, you can even twiddle with a standard AM receiver to "stretch" it down to 518. (sometimes just fiddling with the "padding" capacitor can bring it down far enough.

Eric