Today, 25 March 2017, the 40 MHz OZ7IGY beacon has been migrated to the Next Generation Beacons platform http://www.rudius.net/oz2m/ngnb The beacon was switched on at the 60th anniversary event for OZ7IGY – the actual birthday is 30 March 2017 making it the oldest ham radio beacon still alive.
The 40 MHz beacon is now frequency and time locked to GPS. The sequence is timed to start at 00 second sending PI4 followed by a short pause then CW ID sending call sign and locator, then pause and carrier until next cycle. The nominal frequency remains the same, i.e. 40,071 MHz. To decode PI4 tune your receiver to 800 Hz below the nominal frequency, just like you do when you want to decode a normal CW signal at 800 Hz. On most radios this is a USB dial of 40.070.200. The output power is 20 W into an omni-directional halo antenna.
This completes the upgrading of the 12 beacons at OZ7IGY transmitting from from 28 MHz to 24 GHz.
PI4 is a digital modulation (MGM) specifically designed with beacons and propagation studies in mind. PI4 decoder download: http://www.rudius.net/oz2m/software/pi-rx
PI4 encoding examples in Arduino C, Atmel C, Delphi Pascal, Microsoft Visual Basic and Microsoft C++: http://www.rudius.net/oz2m/ngnb/software.htm
PI4 online encoding and frequency calculation: http://www.rudius.net/oz2m/ngnb/pi4encoding.php
PI4 specification: http://www.rudius.net/oz2m/ngnb/pi4.htm PI4 is a cousin of JT4, JT9 and WSPR.
OZ7IGY homepage: http://www.oz7igy.dk
73 – Bo, OZ2M