The AREG HF receive site, located ~100km north of Adelaide, in South Australia, is now operating a publicly accessible KiwiSDR 4 channel receiver. You can access the service from the following web address:
AREG wouldn’t have been able to make this possible without the support of Sam from Swoop Internet who provide wireless internet access across the Barossa Valley and northern Adelaide Plains. Thanks team for your support of experimental Amateur Radio!
Using the KiwiSDR
For first time KiwiSDR users the following notes should be considered
- Windows: Firefox, Chrome & Edge work; IE does not work.
- Mac & Linux: Safari, Firefox, Chrome & Opera should work fine.
- Open and close the panels by using the circled arrows at the top right corner.
- You can click and/or drag almost anywhere on the page to change settings.
- Enter a numeric frequency in the box marked “kHz” at right.
- Or use the “select band” menu to jump to a pre-defined band.
- Use the zoom icons to control the waterfall span.
- Tune by clicking on the waterfall, spectrum or the cyan/red-colored station labels.
- Ctrl-shift or alt-shift click in the waterfall to lookup frequency in online databases.
- Control or option/alt click to page spectrum down and up in frequency.
- Adjust the “WF min” slider for best waterfall colors.
- See the Operating information page and Design review document for further information
A spectrograph provides a quick-look indication of HF band activity over a given time period. We produce a spectrograph covering three days of HF activity from one of our KiwiSDRs. This is updated every 10 minutes.
FT8 Multi-Band Skimmer
The FT8 Skimmer is the latest addition to the VK5ARG system. Using a 125-14 Red Pitaya multiband SDR and software from Pavel Demin (see here) AREG is now able to give you a near real time view of what FT8 signals are audible here in central southern Australia.
The Red Pitaya is on loan from Josh VK4JNA. Thank you for contributing this very interesting experiment to the site. It certainly provides an interesting insight into what bands are open when!
AREG runs a SSTV Skimmer at the site, listening for all SSTV modes on 14230 USB, and 7171 LSB.
The live received images are available here: https://botsin.space/@aregsstv
Thanks to Michaela VK3FUR for the SSTV skimmer software!
AREG continuously monitors the performance of the remote SDR site, comparing the median noise level to the upper 95th percentile level to produce a metric of Signal-to-Noise ratio, or SNR. The SNR can be observed to vary throughout the day as the HF propagation environment varies.
HF Receive Antenna Details
The receive antenna shared by all the HF receivers is a broadband monopole design, approximately 8m high and 4m wide, and has a <2.0:1 VSWR from 7 MHz to 40 MHz. 32 x 15m long ground radials are used to lower the elevation pattern of the antenna. The antenna location on top of a large hill also helps to lower the elevation pattern even further.
A rough diagram of the antenna construction is here:
The feed from the antenna enters the site equipment hut via a lightning arrestor system consisting of a ~300V spark gap, followed by a 90V gas-discharge arrestor, then a transient limiter device. The signal is then fed into a distribution amplifier consisting of a Motorola CA2818C amp (~18 dB gain, 5dB NF, 45 dBm IP3) and a 24-port splitter, providing ample ports for further expansion. A 1.8 MHz high-pass splitter has been installed prior to the amplifier to avoid overload and inter-mod issues from AM broadcast stations.
Over and above the equipment the club has purchased for this project, there are several members who have made a direct donation/loan of equipment or who have contributed directly to the development of the site. Special thanks goes to:
- Steve Adler VK5SFA
- Mark Jessop VK5QI
- Matthew Cook VK5ZM
- Peter Murphy VK5KX
- Andrew Hall VK5AKH