VIARC welcomes new prefixes

The Vienna International Amateur Radio Club (VIARC) proudly announces that the VIARC will operate stations under the newly released callsigns of C7A and 4Y1A as a host institute.

The callsign block C7A-C7Z is allocated to the World Meteorological Organization (WMO) and 4YA-4YZ is allocated to the International Civil Aviation Organization (ICAO). VIARC is operating a UN amateur radio station with the callsign 4U1VIC at Vienna International Centre which hosts numerous UN organizations and other international organizations.

VIARC welcomes the new prefixes, C7 and 4Y, which are allocated to the UN organizations. Activations of these new callsigns will attract attention from all over the world, which will assist promotion of these organizations, as well as a whole UN system.

The new callsigns, C7A and 4Y1A, will be activated in special occasions related to the organizations as commemorative operations, such as World Meteorological Day or International Civil Aviation Day.

OZ7IGY - 23 cm beacon now on Next Generation Beacons platform

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

OSCAR-11 / UOSAT-2 celebrates 30 years in orbit

UOSAT-OSCAR-11 has now been in orbit for 30 years and remarkably its signal on 145.826 MHz FM (AFSK 1200 bps ASCII) is still being received.

OSCAR-11, also known as UOSAT-2, was designed and built by a team of engineers at the University of Surrey in Guildford, Surrey, UK as the successor to OSCAR-9 / UOSAT-1.

It was launched from the Western Test Range at Vandenberg Air Base, in Lompoc, California along with LANDSAT-5 on a Delta 3920 rocket on March 1, 1984.

OSCAR-11 was the most rapidly designed OSCAR, going from inception to launch in only five months. It was also the first amateur satellite to carry a digital communications package into Earth orbit, and the first to be controlled by a CPU running software written in the high-level programming language “Forth”.

OSCAR-11 carries beacons in three amateur radio bands.

The 145.826 MHz beacon transmits FM Audio Frequency Shift Keying (AFSK) 1200 bps ASCII data. It the early years it also transmitted a voice message from the digitalker experiment.

The 435.025 MHz beacon transmitted either 1200 bps FM AFSK or 4800 bps PSK data. This beacon was used to downlink information from the Digital Store and Readout (DSR) Experiment, which includes CCD Earth image data, results from the Particle Wave Experiment, and engineering data from the RCA COSMAC 1802 CPU.

The 2401.5 MHz beacon transmitted FM and PSK signals. Antenna polarization for all three beacon transmitters is left-hand circular (LHCP). Only the 145.826 MHz beacon is now operational.

Addition OSCAR-11 information - http://www.g3cwv.co.uk/oscar11.htm

OSCAR-11 page on the DK3WN satellite blog - http://www.dk3wn.info/p/?cat=47

SSTL Blog – Happy 30th Birthday to UOSAT-2 - http://www.sstl.co.uk/Blog/March-2014/Happy-30th-Birthday-to-UoSAT-2-

OSCAR-9 and OSCAR-11 TV News Reports - http://amsat-uk.org/2011/10/30/oscar-9-and-oscar-11-tv-news-reports/

BBC Micro ASTRID UoSAT receiver and AMSAT-UK Software Library - http://amsat-uk.org/2011/12/11/bbc-micro-and-amsat-uk-software-library/