AREG Annual General Meeting – Friday August 16th 7.45pm

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The Amateur Radio Experimenters Group Inc will hold it’s Annual General Meeting on Friday August 16th, at the Fulham Community Centre, Phelps Court, Fulham, starting at 7.45pm.

The AGM will recap the year that was for AREG with the presentation of the reports by the committee. All positions will then be declared vacant, and the election of the office bearers and committee will be held.

After the AGM, refreshments will be served and there will be ample opportunity to socialise and talk about the exciting year ahead!

Visitors are always welcome! We hope to see you there!

Project Horus #53 Launch Announcement – 10AM Sunday 25th August

The next Project Horus launch is currently planned to fly on Sunday the 25th of August (weather permitting), with a planned launch time of 10AM. As usual, there’s always the chance the weather for the planned launch date may not be suitable, so if necessary, the backup launch date will be Sunday the 1st of September.

The launch site will be the usual Mt Barker High School Oval. Launch crews should be on-site around 9AM. If you haven’t attended one of our launches before, this is a great opportunity to come along and see what’s involved first-hand!

WiFi Pineapple Payload

WiFi Pineapple

This flight will be the first of hopefully many more payloads proposed and developed by AREG club members under the Project Horus Member Payload Launch Program. Derek VK5TCP’s payload is a WiFi Pineapple board – a WiFi penetration testing device developed by Hak5. The payload will be ‘war-ballooning‘ throughout the flight, recording the SSID of all WiFi access points it can receive signals from. It will also be broadcasting an open WiFi access point (‘VK5ARG’) on the 2.4 GHz band. The payload will be using a ~11 dBi patch antenna pointed directly downwards.

To encourage community participation in this launch, there are two challenges associated with this payload:

  1. Get your Access Point SSID observed by the payload! – Set up a WiFi Access point connected to a high gain antenna pointed at the payload. After the flight we will publish a list of all SSID’s that were observed, and at what altitude they were spotted. For your best chance at being observed, beacon using the lower-speed 802.11b mode.
  2. Recover the secret message! – Connect to the access point on the balloon while it is in flight and retrieve a secret message from a web server running on the payload. This will be a serious challenge to achieve, and will require the use of high-gain antennas on the ground. Our link budgeting suggests that the full 4W of allowable LIPD Class License EIRP will be required to connect to the payload. Amateur radio operators with an advanced license are permitted to use any power level up to the limits of their license conditions. The web server will be running on the IP address 172.16.42.1, and clients can either accept a DHCP lease, or use a static IP address between 172.16.42.150 and 172.16.42.200.

To have the highest chance of success, stations will need to be situated directly underneath the flight path, with antennas pointing upwards to the payload. A map of the predicted flight path will be posted closer to the launch date.

Wenet Imagery Payloads

Image received via the Wenet Payload

This flight will also fly a ‘Wenet’ high-speed imagery payload, as have been flown on many previous Horus launches. The centre frequencies for this transmission will be 441.200 MHz. This payload will be downlinking HD pictures throughout the flight, which will be available at this link:

http://ssdv.habhub.org/

Reception of the Wenet signal requires a RTLSDR and a Linux PC/Laptop. Instructions on how to set up the required software are available here.

 

Telemetry Payloads

As always, we’ll be flying the usual assortment of telemetry payloads, including:

  • Our usual 100 baud 7N2 RTTY telemetry on 434.650 MHz USB. This can be decoded using dl-fldigi, with a reception guide available here. Recent testing of dl-fldigi’s decode performance has found that the auto-configured RTTY receive bandwidth is too narrow, and can detrimentally impact decode performance (by up to 3dB!).To fix this, open dl-fldigi, and in the Configure menu, select Modems, and then go to the ‘RTTY’ tab. Drag the ‘Receive filter bandwidth’ slider to 200, then click ‘Save’. Note that this setting will be reset whenever you hit the ‘Auto-Configure’ button!
  • 4FSK Telemetry decoder

    The new 4FSK Binary telemetry will be transmitting on 434.660 MHz USB. This uses a separate decoder, with setup instructions for this available here. This telemetry payload will soon become the primary method of tracking the flight – the RTTY payload is expected to be retired in a few launches time.

 

Tracking of the flight will be available on the HabHub Tracker, available at this link. (Note that other balloon launches will also be visible on this page, including the Bureau of Meteorology launches from Adelaide Airport).
Follow the #horus53 hashtag on Twitter for updates from the launch and chase teams on the launch day.
Stay tuned for updates closer to the launch date…
73
Mark VK5QI

Next AREG Meeting: RF Transformers – Theory into Practice – July 19th

The next meeting of the Amateur Radio Experimenters Group will be held on Friday July 19th. Doors open at 7.15pm with the presentations starting from 7.45pm.

AREG is very pleased to announce that our guest speaker for the evening is Neil Abraham VK5KA.

Neil has a lifetime’s experience designing RF transformers (among many other things) for a prominent  commercial HF radio manufacturer here in South Australia. In this presentation, Neil will open a window into the world of RF transformers and impedance matching, showing how they can be used in your every day amateur radio station experiments.

Neil says the following about his presentation:

  • I am not going to cover every thing there is to know about RF transformers.
  • I hope to give you enough info so you can design and make your own transformers.
  • I am going to limit this to transformers that are used  to help match HF antennas and feed lines.

If ever you have experimented or had a desire to experiment with designing your own antennas, invariably at some point you will face the issue of how to match that antenna to your transmitter. This presentation will be a great introduction to this most useful aspect of the radio art-form.


Visitors are most welcome! Following Neil’s talk, there will be a short business meeting, followed by tea, coffee and cake and a chance to talk about your own antenna matching challenges with Neil. We hope to see you at the club!

Where do we meet?

AREG meetings at the Fulham Community Centre (formerly known as the Reedbeds Community Centre), on Phelps Court in Fulham.

 

Next AREG Meeting: Club Remote SDR Project – HOWTO Night

AREG has long been seeking a location to establish a remote SDR receive site as a way of allowing members to escape the ever increasing levels of RF interference one sees in suburbia. Finally, the beginnings of this project are taking shape, with a trial system now in place at a location ~100km north of Adelaide.

This meeting will introduce the KiwiSDR system, and show people what was installed , as well as how to use it. We will also show the next steps with the antenna system and talk about ways of using the SDR system in your every day activities. We will also talk about the wider worldwide SDR network and how you can find your way around it.

(It should be noted that the system itself is being restricted to members only at this time due to the temporary nature of the trial site and internet feed).


The meeting will be held on Friday June 21st at the Fulham Community Centre, 1 Phelps Court, Fulham. The doors will open at 7.15pm with the meeting to start promptly at 7.45pm The presentation will commence immediately after a short business meeting.

Members and non members alike are both welcome at club meetings. If you would like to know more, why not come along and introduce yourself!

Automatic Radiosonde Reception – AREG Style!

Thanks to Mark VK5QI, AREG is pleased to announce a new service has been added to the VK5RWN Repeater site. Mark has been developing a RadioSonde automated receive system which allows all of the Bureau of Meteorology weather balloon data to be collected and be made available on the internet. The data is available via the SondeHub instance of the HabHub High Altitude Balloon Habitat platform. You can access it here:

What can you see? Where all the active weather balloons are right now!

If you’re located in South Australia and are considering going out to recover a sonde, or have recovered one, please use the Facebook Group or the mailing list to announce your intentions! This helps avoid disappointment if others are intending to recover the same sonde.

Want to learn more? Read on…..


For quite a while now I’ve been interested in tracking and recovering radiosondes. These are meteorological instruments regularly launched by weather balloon from many locations around the world. Here in South Australia the Bureau of Meteorology launches them from Adelaide Airport twice daily (2315 and 1115Z), along with a few other locations around the state.

A Vaisala RS41 radiosonde found with the help of the radiosonde_auto_rx tracking network!

Radiosondes transmit in the 400-403 MHz band (usually on either 400.5/401.5/402.5 MHz), and there is a range of software, both closed and open source available to decode their telemetry. Not being entirely happy with the existing offerings, I started work on my own software, which became radiosonde_auto_rx (or ‘auto_rx’ for short).

auto_rx runs on a Raspberry Pi (or any other Linux machine) and automatically scans for and decodes radiosonde signals. Telemetry is uploaded to APRS-IS and the Habhub tracker for mapping purposes, and can also be viewed locally via a web interface. Most of the common radiosonde models are supported, including the Vaisala RS41 which is launched here in Adelaide. There are currently 147 auto_rx stations in operation worldwide (16 here in VK5), and so far (as of 2019-05-25 10Z) 19415 individual radiosondes have been logged.

So why do I bother doing this? Many radiosondes are (in part..) highly recyclable! The Vaisala RS41 contains a good quality GPS receiver, a micro-controller, and a radio transmitter – perfect for re-programming for use as a high-altitude balloon payload, as we have been doing on many recent Project Horus flights. In fact, the RS41 is the ‘reference platform’ for the new high-performance balloon telemetry system developed by David Rowe and I.

Chasing and recovering radiosondes is also great practice for Project Horus launches, with a few of the new Horus regulars starting out tracking radiosondes, and many others around VK5 regularly out chasing the BOM’s radiosonde launches. We use the same mapping software for both radiosonde and Horus chases.

To help improve tracking coverage, I proposed to install an auto_rx receiver station at one of AREG’s premier repeater sites, overlooking the Adelaide plains. Thanks to the generosity of AREG members in approving this proposal, the receiver was installed over the easter break. A big thanks to Ben VK5BB for assistance in fabricating an antenna bracket, and helping with the installation!

Hardware Details

The auto_rx receiver station installed in a rack at the site.

The auto_rx receiver hardware consists of a Raspberry Pi 3, with two RTLSDR v3 dongles attached, allowing simultaneous reception of 2 sondes. The incoming RF from the antenna is filtered through an interdigital filter (passband 400-403 MHz, stop-band attenuation > 90 dB) before being going through a preamplifier and splitter to the two dongles. The estimated system noise figure is about 5dB, mostly from the insertion loss of the filter. Given this is a very RF-noisy site (co-located DSTAR repeaters, and many commercial services on a tower a few hundred metres away), the higher noise figure is an acceptable tradeoff – without the filter the receivers would immediately overload!

All the equipment is mounted within a 2RU rack-mount chassis, with all power and network inputs heavily filtered to avoid coupling in unwanted RF. The total power draw of the unit is ~10W.

View from the antenna!

The antenna is an AEA co-linear (kindly donated to the project by Ivan VK5HS) mounted to the side of the repeater hut. Being ~450m above sea level, the antenna has direct line-of-sight to the Adelaide airport, and essentially anywhere to the west of Adelaide.

Receiver Performance

Receiving a radiosonde on the ground at Adelaide Airport

With such excellent line-of-sight, the station regularly receives signals from the Adelaide Airport radiosondes before they launch, and often even during the ground-test and calibration activities performed on the radiosonde within the Bureau of Meteorology building at the airport.

Also often visible are radiosonde launches from the Ceduna and Woomera receiving stations, which typically rise above the horizon when they reach ~10km altitude. Coverage to the east is not quite as good, being blocked by the Adelaide Hills, however radiosondes are regularly tracked down to ~1 degree elevation.

Would you like to know more?

  • More information on the radiosonde reception software is available on github at https://github.com/projecthorus/radiosonde_auto_rx .
  • A conference presentation delivered by myself and Michael Wheeler (VK3FUR) where we discuss the re-use of the Vaisala RS41 radiosondes is also available (see below)
  • You can track radiosondes launched from Adelaide Airport (and many other launch sites around the globe!) by visiting the Habitat Tracker at this link.

Thanks again to all those who helped make this possible!

73 Mark VK5QI

 

Next Meeting: Friday 10th May – Member Lightning Talks

The next meeting of the Amateur Radio Experimenter’s Group will be held (yet again) one week early on Friday May 10th. This time it is a result of the Federal Election which has cancelled our hall booking for our normal night of May 17th. The doors will open at 7.15pm with the business meeting commencing at 7.45pm. The presentations for the evening will begin by 8.00pm. The event will be followed by coffee and cake!

AREG Lightning Talks

Photo by Mark VK5QI of Lightning over Adelaide 24th October 2014

This months meeting is a return to one of our favourite formats, the member lightning talk. While the talks are not about “lightning”, members are invited to give a lightning fast 5 minute introductory presentation on their latest experiment or project. Our time keeper Mark will keep things moving ensuring a lively and diverse range of topics can be covered over the 30-40 minutes of the presentations.

Members who would like to make a presentation should announce it on the club mailing list beforehand so we can plan the program order accordingly, although “drop ins” on the night will also be welcome. Projector slides if you want to show something should be sent to Grant, VK5GR on email prior to the event.

Afterwards, members of the audience will have the opportunity to get up close and personal with the presenters and talk to them in more detail about their projects and experiments. In this way we hope to promote sharing of what experiments the members are undertaking at this very moment.


Visitors are always welcome!

AREG is very happy to welcome visitors to our club meetings, so come along and find out what the membership of AREG is experimenting with!

The club meets at the Fulham Community Centre, Phelps Court, Fulham.

We hope to see you there!

FreeDV QSO Party a success despite trying conditions

This weekend just gone marked the second FreeDV QSO party (the first was 3 years ago). The aim of the event was to encourage people to come and take a look at FreeDV, load up the software and give it a try. It had the added benefit of stimulating a lot of FreeDV activity on the bands as well which was great to see.

Reports have come in from 4 continents of local activity in those regions. So far, however,  there havent been any reports of any inter-continental contacts with VK5ARG or other VK stations. Conditions were certainly difficult but at least regional activty was spawned across the globe! The key thing is that there are now more stations active and capable of FreeDV. It will only be a matter of time before we start seeing regular inter-continental FreeDV QSOs taking place!

Activity Around Australia

Australian activity was predominantly on the 40m band centered around 7177-7185kHz. At times on Saturday afternoon there were 5-6 stations on air simultaneously with lots of calls being swapped back and forth around the continent. Much of the activity used the FreeDV700D mode although at times FreeDV appeared more reliable. Selective fading was identified as a particular challenge during some of these QSOs (see above) even within 1kHz of bandwidth.

Stations were logged between VK1/2/3/4/5/6 either on 40m or 20m, VK FreeDV 20m activity was predominantly on 14130-14135kHz. More on this later.

From the VK5ARG logs it was noted that probably 1 in 2 stations contact was made with were trying FreeDV for the very first time. That alone made the event a roaring success in our eyes.

QSO Party report from the UK/Europe.

Mike G4ABP reported that European propagation has been poor in recent days, as was the case on the day of the QSO party. Consequently, he was not expecting to hear anyone from outside Europe.

Participation from Europe was not great, with about 10 European stations appearing on FreeDV QSO Finder, only one of which I knew previously. Mike monitored QSO Finder for about 16 hours, and had never seen it so busy, (particularly with US stations). Attempts were made via QSO finder to set up European QSO’s, but stations were out of range due to poor propagation. 

Activity around North America

Walter K5WH reports that with all the publicity of the event coming up there has been a great explosion of stations giving it a try, and we have worked with several dozens of stations helping them configure and test out their stations prior to the event.

“The FreeDV QSO finder has been really active with a great deal of interest in trying out the mode. There were a great deal of stations that were busy on the normal US frequency of 14.236 making contacts all day, even if they were not in the contest itself. So from my prospective, even though we did not have much success in the US with the contest, all of the enhanced activity on FreeDV leading up to the contest has really created some great attention and hopefully a lot of new stations to help us keep this mode very active. For that reason alone I would have to say this was an outstanding success for its 1st event.”

Mel K0PFX reported “Yes, the FreeDV QSO party created a lot of interest here in the US as reflected in the number of stations found on the QSO Finder throughout the time period.  I did work a few stations who were not on the Finder indicating there were more around and I am sure, many were just “listening” to see what they could decode.  W4BCX,

Ray in Florida I heard working a number of stations attributing to his great location and excellent signal.  From the NE US, WF1C was worked and heard calling other stations.   And, of course Gerry, N4DigitaVoice was in there working them on his Flex 5k which is an excellent radio for this mode.

From Mexico, XE2JC was there and I was able to decode him but never worked him.  However, I believe Ray worked him. 

Despite the low sun spot activity and the Florida QSO SSB party QRM, we all had fun in the party and good to see all the activity it stirred up.  Thanks to Grant, VK5GR and others for the organizing the event.  I look forward to the next one.”

Activity in South America

Not to be out done, we also had a lot of interest from South America with activity by a number of Argentinian stations. Logs have been received from Alex LW4DFA who worked a number of stations on 20 and 40m as well as Jose LU5DKI who worked ~8 stations again across 20 and 40m as well as several on 80m!

Thanks guys for your interest before and during the event. Please encourage those you worked to also submit logs!

Its not too late!

Now is the time, if you haven’t already done so already, to submit your FreeDV QSO party logs! We would love to see who was active and how they got on! You can send your logs to:

Log Submission:

You MUST submit your ADIF formatted log via email within 7 days after the event to:

FreeDV.QSOParty (at) areg.org.au


Finally, a huge thanks to David VK5DGR for creating this fascinating mode and to all of the operators that decided to give it a go this year during the FreeDV QSO party.

David VK5DGR – Creator of FreeDV

AREG April Meeting THIS FRIDAY – Introducing FreeDV!

Thanks to Easter this year, the AREG meeting is being held 1 week early on Friday April 12th, starting at 7.45pm. Doors open at 7.15pm.

This months presentation is by David VK5DGR, who will introduce FreeDV, talking about it’s capabilities and development as well as how you can try it yourself.

David will also discuss the latest developments in FreeDV and will hopefully give us a sneak peak of what is coming just around the corner.

We will also discuss the up-coming FreeDV QSO Party, the rules and what you need to do to be able to take part! The FreeDV QSO party is being held over the weekend of April 27th and 28th.


At the club business meeting we will also be discussing a working bee to recover the original attempted remote SDR site over the Easter/Anzac day break as well as the pending River Paddling Marathon 200 community event which is supported by AREG each year over the June long weekend.

So why dont you come along and find out what we are up to today in the Amateur Radio Experimenters Group Inc. The clubrooms are located at the Fulham Community Centre, Phelps Court, Fulham.

We hope to see you there!