The club operates beacons on 2m and 23cm to assist both local and distant Amateurs with equipment testing and propagation monitoring.
2 Metres
Location: Isaacs Ridge, ACT Australia
Grid: QF44ma
Latitude: 35°21’56.01″S
Longitude: 149° 7’8.45″E
Altitude: 800 metres
Frequency: 144.410 MHz
Callsign: VK1RBM
Power: 10 watts
Antenna: “Big Wheel” at 6m AGL
Modulation: FSK CW alternating with GE1
Status: Operational
The beacon has two sequential modes
1) FSK CW. Nice shaped waveform (no hard edges) with 500Hz shift at a speed of approximately 10 wpm. Negative frequency shift is Fc-250Hz, positive is Fc+250Hz, so tune a USB receiver maybe 600Hz low to hear it.
2) GE1-1. This is a subset of a 10 gig EME mode with a simple chirp up, chirp down ASCII representation of VK1RBM. The chirp sweep is -400 to +400 Hz and has a period of 16384/24000 seconds.
The mode also mitigates decoding problems from aircraft doppler or meteors etc over long paths. The effective noise bandwidth is about 1.5Hz.
3) There are a few seconds of steady carrier between GE1-1 and the morse for waterfalls.
Frequency stability is not important for this beacon; it has a TCXO and is not GPS locked and there is no timing to the minute etc because the mode does not need it. If your radio is tuned off by 50% of the bandwidth, say 400Hz, you’ll only lose about 3dB. The sweep width was chosen to fit through SSB radios with loads of room for error, and inside an 800Hz envelope of beacon allocation since they are all stacked together a couple of kHz apart.
23 Centimetres
Location: Mt Ginini, ACT Australia
Grid: QF44aa
Latitude: 35°31’47.18″S
Longitude: 148°46’20.20″E
Altitude: 1,762 metres
Frequency: 1296.410 MHz
Callsign: VK1RGI
Power: 10 watts
Antenna: Slot antenna at 13m AGL, horizontally polarised
Modulation: FSK CW
Status: Operational
FSK CW. Nice shaped waveform (no hard edges) with 500Hz shift at a speed of approximately 10 wpm. Negative frequency shift is Fc-250Hz, positive is Fc+250Hz, so tune a USB receiver maybe 600Hz low to hear it.