How to Home Brew a 20-6m HexBeam for HF – Next AREG Meeting

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The next meeting of the Amateur Radio Experimenter’s Group will be held on Friday September 20th. The presentation tonight will be given by Theo VK5IR who will take us through what he has learned as he has set to home brewing his 20-6m HexBeam antenna. The HexBeam antenna design is well known to many in AREG but Theo is the first in the club to home brew one. This could kick off a whole new round of antenna construction experimentation at the club!

AREG meets at the Fulham Community Centre, Phelps Court, Fulham. Doors open at 7.15pm with the meeting starting at 7.45pm sharp. Visitors are most welcome!

Horus 53 – Flight Report

Horus 53 was the first launch in the Project Horus Member Payload launch program, which features new payloads developed by AREG club members. This launch’s payload was the brainchild of Derek VK5TCP, and was a Hak5 ‘WiFi Pineapple’, a wireless penetration testing device which was configured to log all WiFi access points it observed, but also broadcast a WiFi access point for observers to try and connect to. Also flying was the usual array of telemetry beacons, and a Wenet imagery payload.

Launch preparations went smoothly, and with excellent (if maybe a little cold) weather, Horus 53 was launched just after 10AM on the 25th of August 2019, by the youngest member of the launch crew – Tom:

Launch of Horus 53! (Photo credit Gerard VK5ZQV)

With launch complete, the balloon filling gear was quickly packed up and the chase teams departed. Chasing the balloon this flight was:

  • Team QI: Mark VK5QI, Will VK5AHV and Chris VK5FR
  • Team Derek: Derek VK5TCP and Derek VK5RX
  • Team LJG: Liam VK5LJG (Solo)
  • Team WTF: Marcus VK5WTF + IMD product

While Mark, Derek and Liam’s teams were focused on recovering the payloads, Marcus’s aim was to situate himself directly under the balloon flight path and try and connect to the flying WiFi access point (more on this later!).

The chase on this flight was fairly uneventful – the balloon ascended as planned, and burst at an altitude of 31.659km. The chase teams headed out along the Karoonda highway, and were able to get well ahead of the balloon and wait near the predicted landing site.

View of the chase-car mapping software near the end of the flight, as is used by the chase teams to navigate.

All throughout the flight the Wenet payload was downlinking stunning imagery of the state:

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With the permission of the landowner, the chase teams were able to access the property where the payloads were predicted to land, and positioned themselves to try and watch the landing. Unfortunately the wind model was incorrectly predicting the ground-level winds as being higher than they really were, and the payloads dropped almost straight down for the last 500m or so, to land right in a tree right next to the road the chase teams had just been on 5 minutes earlier! The Wenet payload was hanging nicely in a tree, and was able to capture images of the chase teams arriving on-site just a few minutes after landing.

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All the payloads (and quite a bit of the balloon…) were accounted for and in good condition, though the wind-vane that adorned Derek’s WiFi Pineapple payload was nowhere to be seen, and likely tore off at balloon burst.

The chase team with the recovered payloads. (Marcus VK5WTF behind the camera)

WiFi Pineapple Payload Results

Derek’s payload performed perfectly throughout the flight, though the narrow beam-width of the antenna used on it did mean it only saw a few tens of WiFi access points. mainly near the beginning and end of the flight. The WiFi access point was connected to successfully during the flight by Marcus VK5WTF, who recounts his experience below:

Equipment at my end was a Linux laptop running Kismet software, with a USB WiFi adaptor (AWUS036H) plugged into a 2.4 GHz gridpack I picked up a Gippstech two years ago. As a backup I also took my own WiFi Pineapple Nano, just to send out SSID beacons for the payload to pick up.

Looking at the predicted path I marked a few places I could use as ground stations, mostly around the Karoonda Hwy. The plan was to set up a table and lay the gridpack on its back pointing straight up, and I found the perfect sized plastic tub to do the job.

First location was the Sunnyside Lookout north of Murray Bridge. Here I could test scanning for the payload and have a first attempt at connecting to it.

At this location I was also getting a lot of other WiFi Access Points that would have been de-sensing the receiver, and the poor front to back of the gridpack antenna would have also been an issue.

After roughly 15 minutes I got my first glimpse of the payload in Kismet as it was going through the 13 km mark somewhere above my head. When I saw VK5ARG come up on my screen, I definitely got excited, the theoretical is reality. But the two minutes I spent checking everything, I lost valuable time before attempting a connection. It was at the peak of its pass when I started (10:54 ACST), and my log shows I made several associations but near immediate drop out, like it was getting about a 0.5-2Hz spin, “:20 trying to associate”, “:20 associated”, “:21 disconnected” occurred 24 times in the log over roughly 70 seconds.

Off to site two, and the current prediction had it going over the site of the old Kulde train station, so that’s where I headed. Once set up, I found that I had enough phone reception to see where the balloon was, but I didn’t need it, Kismet was seeing the SSID already, time to attempt a connection. Height was about 7km, and it was flying about 4 km by ground west north west of me.

In and connected first try (12:09 ACST), but not getting a lot of data, then the connection dropped, likely still spinning, lets try again… Bam, I’m in! From here the connection stayed up and was strong until it started raining and I disconnected everything; but I was connected for around 3 minutes. At the time I disconnected the height was 4.6 km, and by ground the payload was around 3km north east. Remember that my antenna was pointed straight up in the opposite direction of gravity.

What was I doing with that couple of minutes? Solving the encrypted messages left on the homepage of the Pineapple.

The first was “SGFtIFJhZGlvIGlzIGdyZWF0Lg==”. Easy peasy, base64, answer: “Ham Radio is great.”

The second was a little more difficult, mainly because there wasn’t a command line linux application to do the job for me. The cipher text: “Cjmpn ovfzn Cvh Mvydj dioj ocz nft rdoc Kdizvkkgzn.” Immediately this looked like a rotation (Caesar) cipher maybe ROT13, so I started writing something in Python; and then the rain came, so cancel that! When I got home, I put a little more work into the second cipher, and the characters where shifted by 5, to reveal the answer “Horus takes Ham Radio into the sky with Pineapples.”

Great job Marcus! Derek is currently working on an upgraded version of this payload with a newer WiFi Pineapple model and better antennas, so it’s likely we’ll be trying this again in the future.

Telemetry Statistics

Once again, we had a great showing of amateur radio operators from around the state receiving telemetry form the balloon, including a few new callsigns decoding the Wenet imagery.

The statistics from the various payloads flown are shown in the tables below:

RTTY Payload

CallsignReceived PacketsPercentage of Flight ReceivedFirst-Received Altitude (m)Last-Received Altitude (m)
VK5APR73662.5%15834746
VK5EU43837.2%125491829
VK5EU-379767.7%77772173
VK5KX-0194480.1%17724598
VK5MHZ65855.9%14256152
VK5QI-984071.3%35324
VK5ST-283671.0%36942173
VK5TRM97782.9%29842780
VK5ZEA50.4%99539063
VK5ZRL-0182469.9%27045354
VK5ZRL-0286573.4%24616214

4FSK (Horus Binary) Payload

CallsignReceived PacketsPercentage of Flight ReceivedFirst-Received Altitude (m)Last-Received Altitude (m)
HWK23311.8%189804215
VK5HS115658.9%105002323
VK5KJP41521.2%67352147
VK5KX-2173888.6%11664157
VK5LJG-9122862.6%187765
VK5NEX161082.1%28804558
VK5QI-9153378.2%35165
VK5ST-1144473.6%32901512
VK5ST-2168786.0%30611911
VK5TRM-12174388.9%18141413
VK5WTF402.0%1263113389

Wenet Imagery Payload

CallsignPackets ReceivedTotal Data Received (MiB)
VK5APR20654650.43
VK5DSP239175.84
VK5EU65611.60
VK5EU-2291877.13
VK5FISH15157437.01
VK5QI (Mobile)11873028.99
VK5KX13366732.63

Thanks to all who participated in receiving the telemetry from this flight – all uploads are much appreciated, and help make the flight much more enjoyable for those spectating from home.

Conclusion

Thanks again to all involved with preparation, launch, tracking and chasing. With an influx of interest in this aspect of the amateur radio hobby, we’re hoping to ramp up the frequency of Project Horus launches, but to do this we need your payload ideas to launch! If you have a payload you would like to fly, take a look at the Project Horus Member Payload Launch Program page and let us know your ideas!

Catch you all at the next flight! 73 VK5QI

Horus 53 - Flight Statistics

MetricResult
Flight Designation:Horus 53
Launch Date:2019-08-25 00:35:51Z
Landing Date:2019-08-25 02:53:17Z
Flight Duration:2 Hours 18 Minutes
Launch Site:-35.07668,138.85643
Landing Site:-35.12053,139.70958
Distance Traveled:78 km
Maximum Altitude:31,645 m

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

UPDATE: Launch was a complete success! A full write-up will be coming in due course…

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

AREG Annual General Meeting – Friday August 16th 7.45pm

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!

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!