The 23 cm OZ7IGY beacon has been migrated to the Next Generation Beacons platform and 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 callsign and locator, then pause and carrier until next cycle. The nominal frequency remains the same, i.e. 1296,930 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 1.296.929.200. Later in spring a new slotted wave guide antenna will be installed resulting in an even better ERP.
The special thing about the 23 cm beacon is that the signal is neither multiplied nor mixed to reach 23 cm. Instead the signal is generated using the Super Nyquist principle per Analog Devices AN-939 paper.
The new beacon uses a Mitsubishi power module, RA18H1213G, but we are not satisfied with the efficiency. So if you have a rugged and power efficient design for 15-25 W for 12 V please get in contact with us.
PI4 is a digital modulation (MGM) specifically designed with beacons and propagation studies in mind.
More information - http://www.rudius.net/oz2m/ngnb
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