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

 

VK5RWN D-Star system upgraded to allow linking to XRF & DCS reflectors

For those who came in late………….

The VK5RWN D-Star gateway and repeater system was upgraded in May June 2018 with a new computer running 64 bit CentOS 7 and the new Icom G3 gateway software.

Between then and March 2019, the system has proven to be relatively stable with only a couple of minor hiccups where the computer has shut itself down? We believe this may have been due to the CPU over heating or something similar? This is still being addressed.

VK5RWN is a D-Star gateway system, registered on the US Root Trust database and primarily runs an application called Dplus which manages the linking and routing functions on the D-Star Internet network between other D-Star gateways/repeaters/reflectors.

As such, users are able to connect to other repeater/gateways and Dplus based Reflectors anywhere around the World, or even to other registered D-Star users via Call Sign Routing, a bit like a “private” call in the commercial PMR world.

In principle, within the D-Star world, there are two D-Star Internet networks, the Dplus/US Root Trust network and the ircDDB D-Star open network. Again in principle, the two are mutually exclusive networks and are not interconnected.

This creates an issue where D-Star users accessing the “D-Star World” via a Dplus connection cannot connect to other gateways and reflectors that are using the ircDDB network and vice versa and are therefore limited to accessing the Dplus REFxxxX reflectors. (eg REF023C)

Hams being hams, they just cannot help themselves, the challenge was there and so software was developed that when installed on the Dplus Icom based gateways, allowed interconnectivity into the ircDDB networks and allow access to the XRFxxxX and DCSxxxX based reflectors. One version of this software is called “g2_link” and is designed to be added to existing Icom based D-Star gateway systems on the US Root Trust network.

Early March 2019, Michael VK5ZEA, who is custodian of the VK5REX D-Star system on lower Eyre Peninsular, advised me that he has rebuilt the VK5REX system and had successfully installed the “g2_link” software with the help of Terry, KA8SCP. Michael also passed on Terry’s contact details, whereupon I made contact and asked Terry if he would mind assisting with installing the “g2_link” software on VK5RWN.

Terry most kindly agreed to assist and arrangements were made that allowed Terry to install the software and set up the necessary configuration and interlocks so that both the Dplus and the ‘g2_link’ accessed networks could be worked via VK5RWN.

This now allows for D-Star users to access VK5RWN via a RF input from their D-Star radios and they may now access both the REFxxxX, XRFxxxX and DCSxxxX reflectors and gateways.

A bonus as part of this new configuration, new Dashboards were part of the set-up and now show the connection status and ‘Last Heard’ lists of the VK5RWN system.

Have a look at

For D-star users, please read the instructions at the bottom of the XRF/DCS Dashboard. This is important as there are two distinctly different “linking” or “unlinking” commands to connect or disconnect to and from REF reflectors and the XRF/DCS reflectors. This is so that the system can differentiate between a request via Dplus or the ‘g2_link’ and allow the respective link request to be actioned or disconnected.

It is recommended for D-Star users to use VK5RWN Port C, the two metre port, for connecting to any of the reflectors as VK5RWN Port B, the 70cm port, is normally permanently connected to the REF023C Australasian/Oceania reflector. Before connecting to a reflector, please ensure that the Port is not currently connected to anywhere else. The VK5RWN B 70cm port may be used, but it must be disconnected from REF023C first.

I wish to thank Michael VK5ZEA for his support and advice and especially Terry, KA8SCP, for his help, patience and advice where I needed to do some house keeping that allows VK5RWN to function as a flexible D-Star gateway, allowing D-Star users access to the big wide world via both the Dplus and ircDDB D-Star networks.

73 Ben VK5BB

VK5RSB Repeater Maintenance – New 70cm Antenna

AREG is pleased to report that its VK5RSB 70cm service is now back to full working order after suffering from an intermittent receive fault for many months now.

The problem was tracked down to a faulty antenna allowing water ingress into the feed line. A new dipole array antenna has now been installed and the feed line has been re-terminated. Early feedback suggests the repeater’s coverage has been restored to normal. Further reports would be most welcome!

The long and short of the story is,

  • The LDF5-50 coax termination connector at the top of the coax was removed and internals examined. Plenty of corrosion was found – all green!
  • The new antenna checked was then checked on the ground with network analyser and was given a clean bill of health before being installed at the top of the tower
  • The coax end at the top of the tower was then cleaned and a new connector was fitted and sealed

Meanwhile,  down in the hut, Paul VK5BX could not help himself. He pulled the rack installation apart and refitted all of the equipment and created additional rack space, helped by Peter VK5APR.

Once the VK5RSB repeater was all connected back up, the system was tested. The team measured 75 watts up the “stick”, with 1 watt returned, an excellent outcome!

AREG wishes to thank all crew on site for their help and participation. The crew were,

  • Ben VK5BB, lead, 1st rigger,
  • Colin VK5ACE, 2nd rigger,
  • David VK5MDF, “gofer” ground member
  • Hank VK5XB, “gofer” ground member,
  • Paul VK5BX, ground technician and antenna tester,
  • Peter VK5APR, ground technician assistant

On return from the site there were a number of QSOs with a number of different people, all gave good signal reports and all QSOs were free from that intermittent receive/transmit noise, including the hourly AREG announcement! Further reports are welcome to secretary (at) areg.org.au

AREG IRLP & DSTAR Gateways Back in time for JOTA

 

After several months of disruptions due to lightning and HDD failures at both the VK5RSB IRLP node and the VK5RWN DSTAR Gateway AREG is pleased to announce that we have been able to restore both services in time for this weekend’s Jamboree on the Air for the Scouting and Guiding communities.


VK5RSB Internet Relay Linking Project Node #6214

The IRLP Node 6214 will be available for use by users supporting JOTA this weekend, 20, 21 October. The node can be accessed via the VK5RSB 70cm repeater on 439.900 (-5MHz) using a 91.5Hz CTCSS access tone.

In the support for JOTA, the prefix access code has been removed for this weekend, thus allowing free access to the node.

Therefore to access remote IRLP nodes,

  • dial in the 4 digit DTMF node address of the remote node.
  • to disconnect the IRLP connection, just dial “73” a the end of the QSO.

AREG wishes the JOTA teams and other users, to have fun with contacts via the IRLP Node 6214.


VK5RWN DSTAR Gateway Restored for the 2m/70cm repeaters

The VK5RWN D-Star repeater and gateway is also now fully functional after its computer rebuild. It’s new computer has been installed and the gateway configuration is now complete using the new ICOM G3 software.

Currently the configuration is;

  • Port C, the 2m port, is unlinked and available for general use or user linking to reflectors and gateways etc (147.0375 +600kHz)
  • Port B, the 70cm port, is permanently linked to Reflector REF023C and will output any activity on this reflector and will repeat local RF activity on the 70cm channel into the reflector network. (438.400 -5.4MHz)

NOTE: Port B may be disconnected from the link to REF023C with the unlink command, “^^^^^^^U” , (the ^ represents spaces)  then it may be connected by the user to another address.

VK5RWN activity is now being reported to various Dashboards,

D-Star network access seems to fully functional. Ben VK5BB reports that he has tested linking to several reflectors through the local gateway as well as connecting directly to VK5RWN via his JumboSpot hot spot successfully.

So, any members or DSTAR users in Adelaide who have an interest in D-Star, have D-star capable radios and are registered on the D-Star system, please give VK5RWN a try out and feedback will be appreciated please?

73 from Ben VK5BB

VK5RWN Internet Gateway Failure – Local Mode Only

Dateline: August 18th 2018 – The VK5RWN D-STAR gateway computer and therefore the D-STAR repeater networking is off line due to a failure of the current computer’s SSHD storage.

Both the 2m and 70cm D-STAR DV repeaters are still on and available for use providing local coverage as D-STAR DV repeaters, however there will not be any access via the VK5RWN gateway to the D-STAR global network until further notice. It will only support local operation for the next few weeks.

The current gateway was very shortly due for an upgrade anyway, so the existing failed unit will not be repaired. The new VK5RWN D-STAR gateway computer will be installed on site, pending some minor works, ie, a new shelf, and the final installation and configuration of the new G3 gateway software. This software has to be installed and configured on site as it needs to see both the D-STAR repeater controller and the respective Ethernet ports during the final configuration.

So sorry folks, the D-STAR gateway system will be down until the new computer has been installed, over the next couple of weeks, pending time available.

If you wish to work outside of the Adelaide area on D-STAR, you will need access to a DV Hot Spot, a SharkRF OpenSpot or JumboSpot, DVAP, Dongle etc.

Please pass this information on to any others who you may hear trying to use the VK5RWN D-STAR system

IRLP Node 6214 back on air!

The AREG IRLP node 6214 via VK5RSB 70cm is now back on air and available for general use.

The IRLP nodes “new” computer is now a Raspberry Pi 2, with modifications to the IRLP board to allow for operation on 3 volts as is used by the Raspberry Pi.

During both the morning and afternoon drive times, Monday to Friday, the node 6214 will be off line. It is available all the time Saturday and Sundays.

Weekday morning:

  • off at 07:00am
  • on at 09:30am

Weekday afternoon:

  • off at 3:00pm
  • on at 7:00pm

Access for IRLP operation still requires the current issued access code.

(details may be found at  https://www.areg.org.au/activities/irlp-node-6214)

DTMF “0” is the only “free” access to advise the status of the IRLP linking.

I will write up a blog report with photos for the AREG web pages in due course.

Feedback on the IRLP operations is most welcome, might need to make some level adjustments???

Ben VK5BB

AREG IRLP Node 6214 Administrator

VK5RWN D-Star repeater site antenna tower replacement.

Back in mid August 2017, the tower supporting the antennas for the VK5RWN D-Star repeater system was damaged during the big blow that accompanied the storms. The tower, which was a section of a Hills Telemast bolted at the roof line of the communications hut, has been in service for about 27 years and was in good order. It appears that the wind loading had been exceeded during the August storms and the tower was bent just above the roof line of the building and the top section with the antennas was approximately 30 degrees off the vertical.

Well, no option, it had to be replaced!

The working bee at the VK5RWN site was scheduled for Tuesday 19 December 2017.

Ben VK5BB was at the site around 0845 hrs local time and the other members of the work crew arrived shortly afterwards.

Apart from initial preparations, and the OH&S site survey, the first job of the day was to erect the scaffolding, on the roof of the building! Gave us very easy access to all antennas for disassembly. The scaffolding was also used for the reassembly, thereby minimising the need to actually climb the tower, though Colin VK5ACE later did, to re-mount the 2m antenna at the top.

From there the antenna equipment was easily removed and the bent tower was cut off just above the bend in the tower (just above the roof line) and the tower easily removed. The coaxes were laid out to one side so as not to be damaged and ready for re-installation.

Whilst the old tower was being removed, other members bolted the new tower sections together ready for erecting. The new tower is two sections of Hills 330mm Butt Section mast, with additional plates fitted at the join of the two sections to provide some additional strength at the join.

The top end of the new tower was lifted (man-handled with ropes) above the adjacent hut and then the base lifted into position near where it was to be mounted. Using the ropes, the tower was then pulled upright, across the gap between the two buildings to its mounting position, loosely bolted in place whilst we marked out where the base bolts were to go, drilled and fitted the Dyna bolts and the tower was firmly bolted in place. Actually went in place quite well with a minimum of jiggling etc!

Lunch time! (about 1300 hrs local)

After lunch, the antenna cross arm and antennas were refitted, thanks to Colin VK5ACE, the main climber/rigger for the day. As the Wi-Fi dishes were refitted, the day started to get a bit blowy but the dishes were pointed approximately in the right directions. The 2m 7 element Yagi for the Broadcast Source transmitter was re-installed as a 3 element Yagi and pointed at Crafers. All coaxes were resealed, dressed and cable tied to the tower.

All antennas are back in their old positions, determined by the lengths of the various coax feeds. The tower, now 9m high, carries a 2m, a 70cm and a 23cm vertical “white stick” collinears, two 200mm Wi-Fi dishes and a 3 element 2m vertical Yagi.

Job done!

All equipment was turned on again and the various systems tested, we even had the Internet back on at the site, so we did get the dish right, either that or it has strong side lobes. (The Internet connection was previously still working even though the dish was pointed at the sky? A relay from the ISS??)

Clean up, and we were gone by 1700 hrs local.

The D-Star operations were checked at the site and later again from Ben’s QTH and all was good, including remote access to both the D-Star and the Broadcast computers.

Crew on site;

  • Trevor, VK5ATQ, roustabout and also supplied the scaffolding, (NERC member)
  • Rod, VK5ZRK, roustabout, (NERC member)
  • David, VK5MDF, roustabout, (NERC member)
  • Colin, VK5ACE, rigger, (AREG member)
  • Jeff, VK5IU, “supervisor” and roustabout, (AREG member)
  • Ben, VK5BB, project manager, 2nd climber/rigger, (AREG member)

Many thanks to the crew who helped during the day and especially Olga VK5FOLG, as she supplied a fresh cut lunch for all and delivered on site about 10 minutes before the lunch break.

Reports from the D-STAR users have reported a significant improvement of signal strengths at Balaclava and Mt Barker on 2m and from Hallet Cove on 70cm, so all appears to be good again.

Next task for the VK5RWN D-STAR system is the upgrade of the computer to a new 64bit system running CentOS 7 64 bit and the new G3 gateway software. This is scheduled for early in 2018.

Adelaide Rally using VK5RSA / VK5RSB Repeaters

WICEN has approached AREG to help with their communications nets during the Adelaide Rally this year on the 7th,8th and 9th of December. For the most part, WICEN will use the VK5RHO Ansteys 2-meter repeater (146.850) but for 2 other stages they are requesting to use the VK5RSA 70cm repeater (438.025). AREG is very supportive of this type of use of the club repeater assets and so naturally has agreed.

The times and stages are:

  • Thursday – Old Norton Summit (approx 2:30pm till 5:30pm)
  • Saturday – Norton Summit (approx 12:30am till 5:00pm)

WICEN may also require access to Summertown VK5RSB (439.900) as a possible backup for a Saturday afternoon stage.

WICEN’s role is backup communications and radio traffic should be minimal.

Amateurs who hear the rally traffic on these repeaters are asked to give WICEN priority access during the event. Your cooperation is greatly appreciated!