2019: A35JT OC-049 Tonga

Late Change: Welcome Ricardo PY2PT to the pilot team

Our original South American pilot has had to withdraw from the team this week. We wish you well Cesar PY2YP and we will be sure to keep in touch!

So as to not leave South American amateurs without an easy way to contact the expedition, Ricardo PY2PT has agreed to take up the reigns. His details, as well as the contact details for all of our pilot stations have been updated on the pilot page of the website.

Thanks Ricardo!


6m EME Amplifier Test Successful!

Good News! We finally had a chance to test the new 1kW 6m amp for the EME station! It works a treat and marks the final confirmation that we can still take 6m EME with us to Tonga (after the mishap with the original amplifier back in July).

A huge thank you to Peter VK5PJ who has donated a 50v 40a power supply to us for the expedition! Thanks also to Bjorn SM7SJR who sold us the amplifier and helped with part of the shipping costs getting it from Sweden to Australia.

A35JT Tonga Expedition: 30 Days out – Final Preparations Underway

We are now 30 days away from departing Australia and heading for Tonga. Excitement is building within our team including Oly VK5XDX, Steve VK5SFA, Andy VK5AKH and Grant VK5GR. Our operators have interests from all of the CW, SSB and Digital worlds so we hope to cater for everyone – propagation willing. Our EME equipment is packed too so expect to find us on 6m via the moon! We are also planning to enter the CQ WW RTTY contest as a Multi-1 station as well as the Oceania DX SSB Contest. We hope both of these entries will provide opportunities particularly for the RTTY and SSB die-hards.

Milestones Reached

We passed several major milestones in recent weeks including the completion and packing of our 40m and 30m 4-square arrays, testing and packing of the 6m EME and 20-10m arrays, initial testing of the beverage on ground receive antenna and an on air test of the 160m inverted L built on our Spiderbeam 12m fibreglass pole (which returned impressive results during the Remembrance Day contest held in VK last weekend).

This week we also completed the first set of payments for our freight shipment to Tonga. This first load consists of the majority of the antenna arrays. All up we are shipping ~250kg of equipment to establish 2x 500W HF stations, 1x 6m EME station and a 3rd 100W HF station. (We had hoped to have more power but alas after the failure of one of our multi-band amplifiers during the 6m EME trials in July we learned a few weeks ago that it wont be returning from repairs in time to make it on the expedition).

On Air Planning & Propagation Predictions

We are finalizing operating plans and studying propagation charts. More information can be found on our operating pages

Please note our operating strategy:

If we are calling for NA, EU or AS we politely request other regions stand by.

However if you are in OC, SA or AF we will accept your call at any time!


When should you look for us? The team at Voacap.com have kindly added our expedition to their Voacap DX Charts page. Just enter your grid square and scroll down to the A35JT entry. The following is a quick summary Zone by Zone of expected conditions.

A35JT Pilot Team

40m 4-square Array by Oly VK5XDX

To assist the A35JT expedition team get quickly dialled in to what bands are open from when for Tonga, we have enlisted the help of various pilot stations around the globe. The role of the pilot stations are to gather SWL reports as to when stations in their area are hearing the DXpedition. SWL reports containing the date, time, band and mode are then compiled and forwarded to the team on the island, so they will know when they are being heard and adjust their operating schedule for various continents to target them at the right time.

NOTE: pilots do not take NIL complaints, requests for certain bands or modes (wish list), etc. These will be considered only after the expedition by our QSL manager via the OQRS Busted Call Request function.

30m 4-square Array by Steve VK5SFA

Our pilots are:

  • Chief Pilot – Bjorn ON9CFG
  • North America – Steve N2AJ
  • South America – Cesar PY2YP
  • Oceania – Chris VK5SA
  • Japan – Joe JJ3PRT
  • Youth & ATNO – Jim AC9EZ

E-mail addresses for out pilots will be published shortly!

We must thank Joe JJ3PRT in particular for his help with our Japanese Web page too!

Donations Welcome

If you would like to support our expedition, please click on the donate button on our website!

Please include your callsign and indicate whether it is a general or a specific EME donation in the Paypal Note!


We must thank both our society and corporate sponsors who have helped greatly with making this expedition possible! As we are quickly learning, expeditions are expensive things to stage. Even modest ones like ours. The support of the DX associations and corporate sponsors is invaluable!

Frequency Plans

Our website also contains full details of our frequency plans.

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Logs and QSL Information

We will be attempting (Internet access permitting) to upload logs to Clublog and to our QSL Manager daily. Thanks to Michael G7VJF our expedition also has access to the DXPedition tools on Clublog!

We are exploring a live logging feed option as well. If we can make it work we will announce it on our website!

OQRS QSL Requests

Our QSL Manager is Charles M0OXO.

LoTW will be uploaded once the team returns to Australia. If you wish to receive a direct paper QSL, please request these via our QSL Manager Charles using the M0OXO OQRS Service. The cost for a direct card is currently $3USD which covers printing and postage (only). You can also request cards to be delivered to you via the QSL Bureau network using the M0OXO OQRS. Bureau cards will be delivered free of charge.

If you wish to send us a Bureau QSL card, please send those to “A35JT via VK5GR” so that incoming bureau cards are routed to the Australian QSL Bureau system.
DO NOT send your own bureau card via your local bureau addressed “via M0OXO” as they will not be delivered. I am not a member of the RSGB bureau and they will not handle delivery of them.

Note: due to WIA (2018) Outbound member QSL policy for DXpeditions, I will reply to all received incoming bureau cards via my QSL manager.  


DX Trophy Awards

If you are participating in the DX Trophy Awards you will be pleased to learn that A35JT qualifies for that award.

So with 30 days to go things are looking good!

We hope to work you all from Tonga in September!

73 from the A35JT DXpedition Team!

A35JT Logo

6m EME & HF trials for the A35JT Expedition – the aftermath

What can I say, it has been an eventful month! After all the preparatory work to date, we took most of the antennas bound for Tonga out to a remote location SE of Adelaide to run shake down trials. It was good that we did, for we learned a few thing that are best learned back home rather than out in the Pacific.

What worked – 6m EME!

One of the key things we wanted to do was repeat the trial of the 6m EME station with the final antenna array with it’s elevation mount on the final Spiderbeam 10m aluminium mast using the M&P Hyperflex-13 feedline we obtained from RF Solutions. This was the first time we were looking to test the entire system end to end. We achieved success 5 deg above moon rise with contact to W7JW. We also heard 2 other stations but were unable to complete with them this time.


What didnt work – 6m EME

6m Beam on it’s elevation bracket

Things were going well until about 2 hours in. Then chaos broke out when the SPE 1.5K-FA amplifier failed catastrophically. This caught us by surprise as we were only driving it to 2/3rds of its output power (running 1kW) with the PA temperature remaining under 65deg Celsius (the documentation said that the amplifier wouldn’t take steps to protect itself until it reached 75deg C). Knowing that JT65 is a demanding mode, we had actively sought to treat the amplifier with care (even ensuring that the K3S was unable to generate more than 12W input to avoid any risk of over-driving it). Unfortunately it turns out it wasn’t carefully enough, although we believed it should have raised alarms etc first.

The fallout of this has been very expensive for the team. While the suppliers have been good with regards to honoring warranty repairs, it has become clear this week that we face the very real chance of the SPE not making it back from repairs in time to be included on our customs import/export documentation. This has thrown several aspects of the operation into re-planning to see what we can do (including back up amplifier purchases).

6m EME – Back on Track

On the 6m EME side, we have already started recovering the situation. We were very lucky that an alternate 1kW solid state amplifier came onto the second hand market just after the failure. The replacement, an M2 Systems M6-1K2 amplifier (the same type Lance W7GJ uses for his expeditions), is now enroute to Australia. We will conduct a followup systems integration test at the QTH of EME operator Peter VK5PJ as soon as it arrives. This will put the 6m EME part of the project back on track. We must thank Bjorn SM7SJR for his help with the replacement amplifier and Peter VK5PJ for the power supply to run it.

What did work – HF Antennas

Also over the test weekend we erected the final configuration of the 30m and 40m 4-square arrays. 30m was the first to air and the tests showed excellent directivity and performance. Steve VK5SFA who had led the 30m 4-square array development project was very happy with the results. 40m was next.

Oly VK5XDX and Steve VK5SFA assembling the 40m 4-square

40m 4-square at Nanda Farm

40m was an array we were watching closely. We had prior to the test weekend seen problems with it when trying to measure it’s radiation pattern in a park in suburban Adelaide. We had been thinking, at the time, that perhaps there were interactions with the local power poles or perhaps even the 30m array, as the directivity was nothing like what was expected.

Unfortunately, once testing began, it became clear that the 40m array did have a problem that we hadn’t seen on the first test earlier in the year. Oly, VK5XDX, then started investigating, aided by the team. Once back in Adelaide, he found a broken joint hiding in one of the 1/4 wave phasing feeders that drove the array. This was causing severe pattern distortion. Oly also made some changes to the ground radial design too. These two issues combined were responsible for severely degrading the 40m performance.

To prove it once and for all, Oly then set the array up again (a time consuming task when undertaken solo), this time on a farm north of Adelaide. Grant then went out to help test it with Oly the following weekend. The results were excellent, and we were met with fantastic reports. Front to back ratios in excess of 20dB (in fact we estimate closer to 25-26dB) were observed and excellent reports were received with stations both in Europe as well as domestically. The 40m 4-square project was finally finished ready for packing.

Progress in other areas

We also did some more testing on the 80/160m antenna at the farmstead and debugged a few more issues. That antenna will receive it’s final shake down testing during the Remembrance Day contest to be held on the weekend of August 16-17th but is now looking very promising. We also hope to test the beverage antenna for the first time during that contest.

Progress has also been made both on the tune and test weekend and over the following weeks, with most of the PC network and Logging / digital modes software integration completed. We are also considering what the 3rd back up transceiver will be and are in fact preparing to potentially have up to 3 stations on air at times (although it should be noted at least one will only be 100W at the time). All up our preparations are on track. For such a small team this has been a huge amount of work, but the testing and construction work we feel will be invaluable in bringing Tonga to the world in September.

HF Challenges still to be faced

Unfortunately we have one remaining challenge to overcome. The loss of the SPE amplifier is a serious blow and our resources wont stretch to any further amplifier purchases at this late stage. We are still following up on sources of a 2nd amplifier for HF as we have reservations that the SPE will not return home before we leave. If these alternate plans come to fruition, we will hopefully be back to our original planned strength before long. We will let you know more as things unfold.


While we have had our setbacks in July, the team is still in great spirits and is keen to get everything out to Tonga and get started. We are now under 60 days to go before we leave Australia and are looking forward to bringing you the best signals we can from the Kingdom of Tonga in only 2 months time! If you would like to support our efforts, donations are most welcome. See our donations pages for details.

A35JT 6m EME Antenna – Mechanical & Tuning preparation

Over the weekend we put the finishing touches on the 6m EME antenna mechanical and packing details and did a first set of measurements to confirm it’s tuning. The antenna, which started life as an InnovAntennas LFA2 6el Yagi can now be elevated for EME work using a tilt bracket designed by Lance W7GJ and built by Peter VK5PJ. The antenna has been modified so it can also be packed down into less than 1.5 metres in length for transport. It has also been adapted to fit out new Spiderbeam 10m Aluminium portable mast that Spiderbeam generously sponsored us with.

Now to pack it into it’s travel case and take it down to Lake Alexandrina next weekend for the trials!

6m Moon-bounce Dress Rehearsal planned for July 6th 0050-1130z

The A35JT expedition team will be running a shakedown test of the 6m EME system we are taking to Tonga in September next weekend. The plan is to operate from moon-rise to moon-set in VK5. We will have elevation control now for the antenna and will be able to manually track the moon through the full lunar pass. The team also visited the site today and now believes that we can operate down to the horizon on moon set, which will benefit the European stations hoping to call us. The callsign to be used will be:

VK5GR – Grid PF94mm

Frequency: 50.203MHz (planned)

Moon Rise = 0050UTC July 6th

Moon Set = 1130UTC July 6th

The team will monitor the ON4KST EME Chat and ask you keep track of our activities there – (in case we have to move due to birdies or other factors).

If you are going to try and call us could you please drop me an email beforehand (to make sure you are in our CALLS3.TXT file).

The intention is to run the same calling procedure as Lance W7GJ uses for his DXpeditions. This way it becomes a full dress rehearsal for when we operate from Tonga in September.

Our station will consist of a K3S Elecraft + SPE 1.5KFA Amp and 12dBi antenna with 0.6dB feeder loss using Hyperflex-13 coax (LMR400 equivalent from Messi and Paoloni). The station is the full portable one we are packing up to send to Tonga in August ready for our arrival in the last week of September. Spiderbeam have helped sponsor our 10m aluminium portable tower for this station and we must say a big thank you to RF Solutions in Queensland who have supported our venture  through the supply of our coaxial cables (they are the M&P cable dealers here in VK).

We have been allowed to run 1kW and 12dBi by the ACMA (our VK regulator) for this trial. We hope with this that we should be able to work the bigger stations at least. We did manage with this setup the work several NA stations + JA, UK, I, OH and S5 when we ran the first test in February as well as hear our own echos. That was without elevation. This time, with elevation and an extended window we hope to work some more.

If you miss us on the moon, also look out for VK5GR on HF. We are taking the opportunity to test end to end the complete Tonga expedition station and will have all of the antennas on air over the weekend. We are setting up on Friday 5th and tearing down late Sunday 7th (perhaps even the morning of the 8th for some antennas). Watch the clusters looking for VK5GR/P on HF.

How to call A35JT – our directed calling strategy

Our DXPedition Calling Plan

We want to work as many stations as possible, while at the same time trying to maximise ATNOs for those located in the hardest to reach locations. As a result, the A35JT team is working hard to provide opportunities for everyone. This however presents a problem with geography and the ionosphere. As a result, you will find us frequently calling for a particular region. The following however will hopefully help you identify the best way to still get into our logs as we do want to work you all on as many bands and modes as possible.

Directed Calling for Europe

One of the principle targets of this expedition is to try to work Europe from Tonga (where Tonga is in the top 60 most wanted list due to the difficult path). The difficulty however is that the principle path to Europe is also a direct line to Asia and Japan. To maximise the chance of successful contact with European stations the team will be calling specifically for EU at times when the band is likely to be open to that destination.

Please respect the operators requests and if you are not located in the target zone being called, please hold your call.

We want to work everyone, but will need to work with the ionospheric conditions we are presented with in order to reach the target destinations.

Asia & North America will not miss out!

We dont plan on leaving out other regions either. Our operating plan is to have 2 stations on air during the EU openings with one on an adjacent band taking calls from all regions or even targeting Asia or North America depending on conditions. Please listen closely to the operator to know which region is being called in order to maximise your chances of getting into our logs.

Asia and North America, if we are not general calling or calling your region, please try looking for us on an adjacent band!

Oceania, South America and Africa – Special Circumstances

The A35JT team is very aware of just how few amateurs are active in these continents. To that end, it is rare that we will see enough activity to regularly call those areas if we are directing calls elsewhere.

The team has agreed that if you are located in Oceania, South America or Africa, we will accept your call at any time, regardless of which specific region we are calling.

This will apply to VK, ZL, Oceania, South America and African stations only. All other regions, please stand by if your region isnt being called, or please look for us on another band.

Antenna preparation continues – 30m & 40m 4-Square Arrays Tested

The expedition team reached another milestone this week with the successful testing of both the 30m and 40m 4-square arrays.These are all home brew arrays including the phase shifting networks and switching controllers. Oly VK5XDX has led the development of our 40m array while Steve VK5SFA has lead the development of the 30m array. We had many helpers on the day including Trevor VK5YFR, Neil VK5KA, Chris VK5SA, Paul VK5SL and Greg VK5LG. We conducted pattern measurements of the arrays and confirmed they were providing the expected 20dB front to bank ratios confirming that they were working properly.. Now, the only remaining project to finish off the 4-square systems is the upgraded remote switching controllers.

The previous week, Steve and Grant completed testing of the 160 and 80m inverted L antennas with great success.

Next up, we will undertake final packaging, run one last shakedown of the station over the test weekend on July 5-8th, and prepare the antennas for freighting to Tonga.

We are doing everything we can to maximize out chances of communications with areas most needing A3 in their logs. Only 3.5 months to go before departure!