AREG AGM: Friday July 16th – Presentation: Central SA Repeater Network

The next meeting of the Amateur Radio Experimenter’s Group will be our Annual General Meeting. This will be held on Friday July 16th.

The guest speaker for the evening will be Dean McGinty VK5HMV who will take us through the construction of the central SA linked 2m/70cm analogue repeater system and provide an insight into how it works. This is the network that the AREG Adelaide CBD Repeater VK5RSA is connected to on 438.025 MHz (-7MHz 91.5Hz CTCSS).

VK5RSA itself is proudly sponsored by KernWi-Fi who arranged access to the new home for VK5RSA atop Westpac House in the Adelaide CBD.

Presentation Details

The presentation will start at 7.45pm ACST, 8:15pm AEST (1015 UTC) from the club rooms at the Fulham Community Centre, Phelps Court, Fulham.

For members who cant (or due to COVID dont wish to) attend in person, the program will also be streamed via Zoom.

Online visitors will be able to watch the presentation via YouTube thanks to Hayden VK7HH’s HamRadioDX Channel.

Links will be posted closer to the event.


AREG AGM 8:30pm July 16th

At the conclusion of the presentation, members will be invited to participate in the AREG AGM via Zoom and in person. The AGM will commence at 8:30pm and is expected to last no more than 15-20 minutes.

The event down at the hall will be run as a COVID Safe event. Note that given the rapidly changing COVID lockdown situation, the AGM will be deferred to being an online presentation should we be prevented from holding it in person at the hall.


If you want to  visit us in person, you can find the clubrooms here:

map

We look forward to seeing you all in July!

Adelaide CBD 70cm Repeater returns to service! (UPDATE)

After several years off air and/or operating from a temporary site in the western suburbs, the Amateur Radio Experimenter’s Group is please to announce that we have been able to negotiate a new home for the club’s VK5RSA Adelaide CBD 70cm repeater!

AREG has entered into a sponsorship agreement with KernWi-Fi, who are supporting the club by facilitating access to one of the premier communications sites in the Adelaide CBD atop Westpac House. At 134m high, this site is on one of the highest buildings in the city! AREG wishes to express it’s sincere thanks to Phil Kern (VK5ZEY) for his support of the VK5RSA repeater. It has been a dream of the club to gain access to the site for nearly 20 years and it is great to see it finally come to fruition.

The repeater itself has been rebuilt by Paul VK5BX & Dean VK5HMV, and was installed by Dean VK5HMV and Shane VK5NRV over this past weekend. This was the culmination of 9 months of discussions and planning by the AREG Committee, members on the repeater sub-group and the KernWi-Fi team.


 

VK5RSA operates on

438.025MHz (-7MHz input)

with 91.5Hz  CTCSS

 


NOTE: The repeater input frequency was changed Monday night due to un-resolvable interference from the co-sited commercial operators. VK5RSA is now operating according to the new 70cm band plan, with a repeater receive frequency of 431.025MHz. This is a -7MHz offset instead of the old -5MHz offset that was in use previously.

But Wait – there’s more!

In addition to being installed atop one of the highest buildings in Adelaide, VK5RSA is now part of something much bigger. It has now joined the growing Central South Australian repeater network, which provides coverage over most of central SA.

The repeaters in the network are:

Location / AreaCallsignOutputInputCTCSS
Adelaide CBDVK5RSA438.025MHz-7MHz91.5Hz
Adelaide RegionVK5RAD439.925MHz-5MHz
Adelaide NEVK5RKW438.050MHz-7MHz
Lobethal / Adelaide HillsVK5RAH146.775MHz-600kHz
Mt Bevor / Murray BridgeVK5RMB146.875MHz-600kHz
Victor HarborVK5RVH147.100MHz-1.6MHz

NOTE: With the network access comes a change in mind set for operators too. For all 6 repeaters to operate together, it is important for users to leave at least a 1 second gap after the repeater tails before transmitting. This will give sufficient time so that all of the transmitters and receivers can sequence correctly thus preventing one or more repeaters from being locked out.

The nominal best areas to access each repeater are shown here:

Strongest Serving Repeater Map (Note Victor Harbor not shown)

The coverage of the system is expected to be second to none in this part of the state. AREG hopes by making VK5RSA part of this network that it will help bring amateurs together on VHF/UHF and will drive new activity on these bands!

We look forward to hearing you on VK5RSA and the link network! Come and give it a go….

VK5RWN D-Star update

For information of all VK5RWN D-Star users, remote connectivity has been re-established late Wednesday evening, 21 October.

So users of Hot Spots, Dongles, DVAPs, you can again log onto the VK5RWN C or B modules.

If you have connection problems, you may need to update your hot spot Host Files. If the problem persists, email Ben VK5BB, and he will see what he can do to provide help.

You can also check the VK5RWN dash board to see connections and the Last Heard list,

vk5rwn.areg.org.au

For those interested in the technicalities, the problem was that when we reconfigured the local router that serves the VK5RWN D-Star computer, we missed setting some ports within the router to allow throughput.

The missing port numbers were not listed within the Icom manual for the setting up the D-Star system. However with some advice from a couple D-Star administrators, we identified the missing port numbers and I also then found them in older set up documents that were not checked in our search for answers. Isn’t that always the way of it?

It turns out that these ports are not needed by the main Icom D-Star system, which was working well without them, but are used by third party software that has been added to the D-Star operating system that allows additional services within the D-Star networks.

Have fun exploring and playing with D-Star.

VK5RWN DSTAR – We’re Back!

We are pleased to report that thanks to the hard work of our dedicated volunteers, in this case Matt VK5ZM, Ben VK5BB and Bob VK5FO, we have completed the cut-over to our new Internet link!

The VK5RWN D*STAR repeater has been reconnected to the internet as has the Weather Sonde receive station. The VK5RWN D*STAR Gateway is active and hotspot users should also be able to connect again to our host server.

(Note: Hot spot users may have to wait a few days to allow the Host Files to update VK5RWN’s IP address. It is also recommended that hot spot users log into their hot spots and force an update to the Host Files).

AREG has now moved to a new internet provider. We would like to thank Phil and Christine at Kern Internet for their help in re-configuring the on site router!

Other Dash Boards associated with VK5RWN are also back online, including the registration page and user access to their accounts.

(You may need to allow a security exception to access the pages the first time you log in via the vk5rwn.areg.org.au.)

Adelaide D*STAR users who are not already members of AREG are encouraged to join our group or make a yearly donation to our running costs, to support the D*STAR system here in Adelaide.

We hope you enjoy our return to service!

  • VK5RWN 2m 147.0375 +600kHz
  • VK5RWN 70cm 438.400 -5.4MHz

Note if there are users in Adelaide that want to experiment with the 1.2GHz ports, please contact us and AREG can look at re-activating them. They were disabled originally after they sat idle for 2 years consuming power for no reason. If interest in D*STAR on 1.2GHz returns we can turn them on again.

VK5RWN D-STAR Update – Progress!

As D-Star users in Adelaide will be aware, the club’s VK5RWN repeater has been disconnected from the Internet for several weeks now. This is due to AREG needing to change internet provider, coupled with installing a new microwave link to the site. This also created downstream problems with the LAN design and router configs at VK5RWN. We are happy to report that we have now made some good progress, with the link to our new provider Kern-WiFi successfully commissioned.

We are not out of the woods yet however. Running multiple 24×7 services on the live internet while making sure the site is not open to hostile online attacks is not a trivial exercise. It is taking us longer than originally hoped, to secure the new connection and re-open all of the services from VK5RWN (including the BOM Balloon tracking station and the DSTAR repeater).  With luck, that should be done in the next 7 to 10 days (after the Oceania DX Contest is complete this weekend).

Stay tuned for further updates! Meanwhile, local D-STAR contacts are still possible via the VK5RWN over the air on 147.0375MHz (+600kHz) and 438.4MHz (-5.4MHz).

VK5RSB 70cm Repeater Service

14 May 2020

Note: VK5RSB is still on air – but its tail is now VERY short. We will rectify the problem with the tail as soon as we can.

5 May 2020

Further update regarding the VK5RSB operations.

In the exuberance of the repeater service crew to see VK5RSB running with the AREG repeater controller, the repeater’s operations in conjunction with access to the IRLP network was overlooked.

IRLP node 6214, is accessed via the VK5RSB 70cm repeater.

The IRLP network managers do not like local repeaters sending “Roger Beeps” and repeater idents out into the IRLP system. This is because such idents etc will be transmitted elsewhere in the world, which is certainly not appropriate!

Under the previous setup of the VK5RSB 70cm repeater, the CW ID was generated within the Motorola Quantar but was transmitted without CTCSS, therefore not keying the IRLP unit and not being transmitted over the IRLP system, which needs CTCSS to be keyed for operation.

Therefore, with this in consideration, the “Roger Beep” has been turned off and the repeater “Tail” has been shortened to 1 second.

The Voice indent will remain for the short term, as any ident generated by the AREG repeater controller will still be transmitted with CTCSS.

The current final solution to this oversight, is to remove the AREG repeater controller and reset the Quantar code plug as had been previously.

The repeater service crew are sorry for any issues that came about from this exuberance.

We trust that all will continue to enjoy and take advantage of the VK5RSB repeaters.

4 May 2020

Just a quick update on the VK5RSB 70cm repeater.

This morning Paul VK5BX, myself Ben VK5BB and the Covid 19 Supervisor, Alesia (harmonic) attended at the VK5RSB site.

Purpose of the visit was to,

  • change over the VK5RSB 70cm repeater Motorola Quantar,
  • one out, one in, setup for operation with the AREG repeater controller,
  • re-fit the AREG repeater controller for the 70cm repeater,
  • check the site installation operation.

The equipment change over was without issue and the operation is successful with the new configuration of the repeater working well.

Noticeable operational changes,

  • 5 second long tail
  • a “Roger beep”,
  • the time out timer resets on the “Roger beep” (so no need to wait for the tail to drop)
  • voice ID
  • on long overs, a low level CW ID will play over top of the QSO.

Many thanks must go to Paul for his perseverance and time in setting up the replacement Quantar and mating it with the AREG repeater controller.

Reports and feedback would be much appreciated please.

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

 

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