Eldon Brown, WA0UWH, has been experimenting with a Parallax Propeller he received for Christmas. Being an avid amateur radio operator, Eldon decided to code up a low power radio beacon on the 30-Meter amateur radio band (10.10 to 10.15 MHz.) He wrote this simple program to generate very slow speed CW (Morse code) radio transmissions (a/k/a QRSS) using the Propeller.
At first he generated the desired signal directly from the Propeller with only the addition of a small attached wire antenna. He went on to modify the design to include a low pass filter (above right) to eliminate the PLL synthesizer phase jitter from the Propeller. He connected a proper outdoor antenna through the filter and is transmitting on 10.1387 MHz.
Check out Eldon’s WA0UWH website for the complete project log.