OpenBeacon circuit diagram


Annotated Schematics

OpenBeacon circuit diagram with troubleshooting notes



Bill of Materials


Windows USB Drivers

These drivers are required for Windows usage.


Linux Client

Linux command line executable control program


Windows Client

Windows command line executable control program


OS X Client

OS X command line executable control program


GitHub Repository

Hardware design and firmware code files


What is OpenBeacon?

OpenBeacon is an open source crystal-controlled QRPp beacon transmitter which can output a variety of slow-speed modes, including QRSS, DFCW, and Sequential Multi-tone Hellschreiber. It is configured via USB port, so there are no jumpers to set and you can easily adjust all of the operating parameters via command line. Once configuration is complete, OpenBeacon may be removed from the PC and operate stand-alone.

OpenBeacon is considered a MEPT (manned experimental propagation transmitter), which means that you should never leave the control of it unattended.


  • Frequency: crystal controlled
  • Available bands: 80 meters, 40 meters, 30 meters
  • Modes: CW, QRSS, DFCW, Sequential Multi-tone Hellschreiber, Glyphcode, WSPR (experimental)
  • Power output (nominal): 30 meters: 300 mW, 10 meters: 100 mW (at +13.7 VDC power supply)
  • Spectral purity: greatest harmonic <-45 dBc
  • Power supply: +5 VDC to +14 VDC
  • Current consumption: 50 mA at +5 VDC, 120 mA at +13.7 VDC
  • Control via USB on Windows, OS X, and Linux

What is QRSS/DFCW?

QRSS is a very slow speed CW operating mode where the length of the characters are significantly lengthened in order to allow weaker signals (QRP) to be able to be received on a special spectrum display with a long integration time of minutes to hours. DFCW is a similar mode, where the carrier is left on, and Morse Code characters are formed by shifting the carrier frequency up a few Hz (FSK). Sequential Multi-tone Hellschreiber (often abbreviated S/MT Hell) uses FSK to “paint” characters on the spectrum display so that they show up as graphical characters. Glyphcode uses the S/MT Hell mode to print two glyphs to represent Morse Code characters, one for a dah and another for a dit.