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Wednesday, July 9, 2008

My Beacon (MEPT) Circuit

Guys have been asking to see the schematic for my 30 meter QRSS MEPT beacon. Here's the oscillator circuit. This actually started out on a plane ride. My son Billy and I were talking about electronics. I drew a basic schematic for an oscillator, and we built one when we got home. It originally used a 20 meter crystal. At one point we were playing "find the oscillator" -- hiding it somewhere in the house, and tracking it down with a Sony shortwave receiver. Now, with some modifications, it is the first stage in my 30 meter MEPT beacon.

An ugly schematic for a rig built with the ugly construction technique. Nothing fancy here. Two feedback amps and a PNP transistor as a switch to key them. I let the oscillator run continuously. (Let me know if you can hear the "backwave"!) About 20 mw out. As you can see, it doesn't take much to get a QRSS signal on the air.

1 comment:

  1. Thanks for posting your schematic Bill. I am building my oscillator now and hope to have it running today. I plan on having my circuit operatonal before I leave on vacation. I will be flying to Kauai next Wednesday and I plan on letting my MEPT beacon run for the 2 weeks I will be there. I don't know the exact details yet but I will keep you informed. My callsign will be W8OAJ/KH6



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