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Last Updated: September 10 2009 15:52

PSK31 Beacon

G1SLE Beacon Keyer Mk2
G1SLE Beacon Keyer Mk2

The Mk2 beacon keyer is a self contained PCB roughly 90 x 65mm. The beacon texts are user programmable via the RS232 serial port. The keyer generates AF tones for both PSK31 and RTTY. The audio tone output level is adjustable up to 3v p-p. Beacons may be in 50 baud RTTY (170Hz shift) or PSK31. Full Varicode and RTTY Baudot (US) alphabets including punctuation are supported.

As with most of my recent designs many of the components are surface mounted types. All resistors and capacitors are in 1206 or 0805 suface mount packages, with the exception of the 2 x SIL resistor networks. As through hole mounted components begin to become less available than surface mounted equivalents I have used surface mount packages for a number of ICs. These are mostly the larger SOIC DIL types which are reasonably easy to manipulate and solder with standard hand tools. The 89C51ED2 is in the common PLCC44 package, however since this part is fitted in a PLCC44 socket which is itself through hole mounted the constructor has no need to solder to the device.

By using the 89C51ED2, a powerful derivative of the long established 8051, the component count is kept very low, resulting in a compact simple design, capable of generating not only PSK31 and RTTY but also various other modes including .WAV file storage and playback. Separate firmware to support additional modes will be released in due course.

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