Sunday, September 4, 2011

Microprocessor controlled CW Beacon

In this project we introduce portable microprocessor controlled CW radio beacon. This CW beacon module is capable to transmit maximum of 64 Morse codes repeatedly in 4.433MHz with 9V DC power source.

This system consists of CW transmitter, ATtiny13 microcontroller unit and low current voltage regulator. Atmel ATtiny13 microcontroller is used to drive the transmitter and thanks to its internal 64 byte E²PROM, we may be able to change beacon data without altering the system firmware.

While at the testing stages we receive this beacon on 10km radius (using Sony ICF-SW7600GR receiver) by using standard telescopic antenna. To get the maximum range it is recommended to use 3m – 4m antenna wire with this transmitter system. At the prototyping /testing stages we try this transmitter successfully with 3.58MHz, 4.43MHz and 6.00MHz crystals.

This system is design to work with standard 9V battery (6F22/6LR61). At the prototyping stages we test this system using 12V and 10V DC power sources and get the same results.

Transmitter of this system is based on Nyle Steiner’s (K7NS) "80m CW transmitter" unit. All the project source codes, schematic diagrams and PCB patterns are available to download at

This project is released as an open hardware project and all the source codes are licensed under the terms of GNU General Public License Version 3 and all the documents, schematics and PCB patterns are licensed under the Creative Commons Attribution-ShareAlike 3.0 license.