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

New Worcester UHF repeater goes on-air

/

The Worcester UHF (70cms) repeater, GB3WU, has received its NoV for operation from the Worcester Radio Amateur's Association (WRAA) club shack in Worcester.

GB3WU was installed by Mike G8TIC and Peter G0WXJ at midday on Sunday, 9th February and test transmissions were made between 12.06 and 12.20 UTC. The repeater became operational at 12.25 after installation was completed.

GB3WU is a "wide split" (7.6MHz) repeater that operates on channel RU66

(430.8250MHz output; 438.4250MHz input) and is accessed by CTCSS sub-tone freuqency 118.8Hz (tone code "J").

The repeater comprises a Tait TB7100 base-station with an NHRC-4 controller at this time. The controller may be upgraded at a later date to link it to the Allstar network in the Midlands and South West...

In order to access the repeater you must radiate the 118.8Hz subtone on your transmission on the input frequency. The repeater will return its callsign in Morse code on first access after being idle for an extended period and will return a 3-tone rising beep as the courtesy tone and drop carrier after approx 2 seconds.

The repeater runs approx 15W RF in to the combiner, splitter and coax to achieve 10W at the antenna which is a 4dBd gain WX1 VHF/UHF colinear and achieves the 25W ERP (14dBW) licensed power. The antenna is at approximately 8m AGL and the site is approximately 80m AGL.

Summary

  • Callsign: GB3WU
  • Location: 1Km NE Worcester City Centre, IO82VE
  • Channel: RU66
  • Output frequency: 430.8250MHz
  • Input frequency: 438.4250MHz
  • CTCSS tone: 118.8Hz
  • Toneburst access: No

New Medium Wave Beacon

/

A radio propagation beacon on the new 630 Metre band has begun in Australia and it encourages reports of its reception.

The band 472 to 479 kHz was granted to VK radio amateurs on January 1 2013 after the World Radiocommunication Conference approved the 7 kHz wide secondary allocation.

It sits just below the AM broadcast band and is now available to radio amateurs in a number of countries.

The 473 kHz beacon is at Mildura in northwest VK3 on the cross-roads of Australian capital cities of Melbourne, Adelaide and Sydney. Strategically located it also aims to further stimulate activity on the band.

The project is the work of Noel Ferguson VK3FI who built it based on a circuit designed by fellow homebrewer Drew Diamond VK3XU, with changes made mainly for available components.

It identifies as VK3FI Mildura followed by 20 seconds of carrier, radiating from an L-antenna against a mast, plus seven radials and some 27 earth stakes.

The beacon is currently turned on at 1100 UTC part-time when VK3FI is present.

Reception reports are most welcome to vk3fi@wia.org.au