Home 8-7-5 Articles FSK RTTY intarface
FSK RTTY intarface PDF Print E-mail
Written by K9XD   
Monday, 20 February 2012 22:03

Here is a great way to save some cash if you need an FSK interface.

We found this at  http://www.w1hkj.com/FldigiHelp-3.21/PseudoFSK.html .I couldn't find an inexpensive small box I liked, so I used the pill bottle.

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This interface dose the same thing the expensive store bought ones do. You take the audio tone from your right audio channel of your computer, running say FLDIGI

http://www.w1hkj.com/ and rectify it and turn the base of a simple NPN transistor on and off giving your shift pin on your RTTY jack on your rig a change in state, so open to ground.

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That's it, nothing more no magic. It takes a few hours to build and works great. I used tantalum capacitors and 2% resistors to keep the tolerance stable over time.

All the parts can be bought at Mouser Electronics http://www.mouser.com/?cm_mmc=google-_-ppc-_-americas-_-Brand&gclid=CNWHl-aOiK4CFdQAQAodZVBC6g

Do not cheep out on the transformer and use something used, buy a new one for $5.00 part number TY-304P, I built two for $25...

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If you build one send us a picture and will post it. 

73's K9XD

Last Updated on Tuesday, 21 February 2012 00:40