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Month: March 2019

Testing 40m 4-Square Array in CQ WPX SSB 2019

Testing 40m 4-Square Array in CQ WPX SSB 2019

Andy VK5AKH driving VK5GR in CQ WPX on the 4-square on 40m

The first major new antenna for the DXpedition has been completed and was taken out into the field for its first on air trials this weekend during the CQ WPX SSB contest.

The Array

Our 40m 4-square array, designed and built by Oly VK5XDX will take full legal power and then some. We verified that the directionality definitely works, being able to switch and see an immediate change in received signals between NA, EU and Asia across the contest. Unfortunately for now, switching involves going outside and replugging the antennas into different ports of the hybrid and phase shifter. We are looking at ways of building a relay switch box to add to the antenna so we can switch it back in the shack.

The array is supported by one of our equipment partners. The 75ohm phasing lines between the elements used cable sourced via Messi & Paoloni in Italy, who make foam based light weight coax that can still take the power needed on our station. This contributes to the whole array (minus the star droppers) weighing in at less than 14kg. It was designed to break down into lengths less than 1500mm so that it can be carried on commercial airlines as oversize baggage.

The Ultraflexx 7 50ohm main feeder used also came from M&P. This cable has roughly half the weight of traditional RG-8 – highly important for a weight limited expedition.

Results on the Air

During the contest, we were frequently asked what the antenna was and were complimented on our signals. We were happy to be able to often get stations in Europe and North America to reply with only 1-2 calls, and were pleased to be able to work some small pistol stations on 40m in the USA during the early evening (our time). It all bodes well for our 40m signal on Tonga in September!

Thank you GDXF for your support!

Thank you GDXF for your support!

The A35JT expedition team is grateful for the tremendous support it has received from the German DX Foundation! With the addition of Steve VK5SFA to the team (who is something of a 160m specialist) and support received from the DX associations, we will be placing some increased focus on our planned 160m operations too!

A35JT gains a 4th team member – Welcome Steve VK5SFA

A35JT gains a 4th team member – Welcome Steve VK5SFA

Steve VK5SFA operating VK5ARG portable in the Oceania DX Contest 2017

The A35JT team is pleased to have Steve VK5SFA join our expedition. Steve will be with us for the first week of the trip during the busy build period and the very busy operating period when we will be running both EME + HF (EME wont be workable in the second week due to sky noise).

Steve brings a wealth of amateur radio experience to the team. As an avid DXer and contest participant as well as his experience as a broadcast engineer he will be an invaluable member of our team. Welcome Steve!

You can now meet all of our team members on our Team page via our expedition website https://vk5gr-iota.net/

Thank you CDXC-UK for your support!

Thank you CDXC-UK for your support!

The DXpedition team is grateful for the support we have received from the CDXC UK Foundation. We will be trying our hardest to make contact with your members from Tonga in September!

Change of Callsign: We are now A35JT

Change of Callsign: We are now A35JT

Licence Received from Tonga

After several months of communications we have finally been issued with our licence to operate on Tonga!

We had a small surprise however when we looked at the issued callsign. It has now changed and our final assigned callsign is A35JT. Never mind!

We have also confirmed that we are not able to operate on 60m this trip. We have, however,  been granted access to 6m to conduct our EME experiments!

So after a quick rebrand of the website, QRZ and Facebook pages our identity is corrected and away we go!

Work on antennas continues

We have also been busy behind the scenes with Oly VK5XDX designing and testing our home brew 40m 4-square array. Weighing in at only 12kg the early tests are promising. We are hoping to run the array for part of the CQ WPX SSB contest at the end of March as a test.

 

 

Thanks to RF Solutions for your support!

Thanks to RF Solutions for your support!

The A35JT DXpedition team is indebted to Carsten VK4OA at RF Solutions for his support of our DXpedition. We have obtained a number of items needed for the DXPedition station through RF Solutions including some of the HYBRIFLEX-13 and ULTRAFLEXXX-7 feedline and connectors for the 6m EME station and the 40m 4-Square array. Team members have in the past also purchased RadioSports Headsets and SPE Amplifiers via his company.

Dealing with a local re-selller has been fantastic for solving customs import hassles and we would heartily recommend them for any VK or Pacific based Amateur Radio operators seeking products from the many brands of equipment that Carsten provides.

A35JT Azimuthal Map & Calling Procedures

A35JT Azimuthal Map & Calling Procedures

Europe is Hard – we will be trying our best!

This map explains well the difficulties faced by stations in Europe working Tonga. Paths into Germany for example pass straight over either the North or South pole. That is why we are planning directional antennas and amplifiers for our activities targeting Europe. We are planning on establishing pilot stations in Europe to help us identify the best times for openings to that part of the world too. More on this soon.

Please respect our directed calls to specific regions!

We will always be working split frequencies and will use directed calling. We please ask stations in Asia and Japan to please stand by as we call for the much weaker European (EU) signals over the pole. We are hoping to arrange things so that only one of the two stations will be doing directed calling at a time so that if say 20m is open to Europe, we will provide a 30m signal at the same time to satisfy demand from Japan.

On FT8 we will also carry out directed calling – and will only answer stations from targeted areas when we have announced a particular call area. Note our FT8 operations will either be using the WSJT-X Fox and Hound mode or FT8 standard mode exclusively (not the other multi-thread variant that has recently appeared). We will announce our frequency plan closer to the expedition, as we need to coordinate with the ZK3 expedition on band usage.

Please note our QSO policy – we will accept calls from Oceania (VK/ZL/YB etc), Africa and South America at any time regardless of which region we are specifically calling, due to the relatively low numbers of stations active in those regions.

Stations in other regions, please understand – this is not to be taken as an opportunity to ignore the directed calling we are making for other regions at the same time.

 

Depending on the unique QSO counts, we may also call for ATNO (All Time New One) only. This is intended to give the small stations a chance to secure at least one contact with us.

 

A35JT Sponsorship Support – THANK YOU!

A35JT Sponsorship Support – THANK YOU!

Group Sponsors

The team wishes to thank the Radio Society of Great Britain (RSGB), the Clipperton DX Club of France and the Amateur Radio Experimenters Group for their generous support of our DXPedition!

 

 

 

Corporate Sponsors

We also wish to thank our corporate sponsors who are helping with some of the equipment costs!

Spiderbeam are helping with masts for our expedition. We are in particular using two of their 10m Aluminium masts for our beam antennas (HF and 6m). These are fantastic for their size and enable us to fly on commercial airlines with all of our antennas without exceeding our luggage weight limits.We will also use a Spiderbeam 12m fibreglass mast for some of the wire antennas on the expedition.

Messi & Paoloni are also helping our expedition with coaxial cable. One of the biggest unseen hurdles on a weight restricted expedition is how to take enough coax to connect everything together. Last used by VK5GR on his YJ0AG expedition, Messi & Paoloni ULTRAFLEXX-7 provides us with RG-213 performance at nearly half the weight per metre. We are also using their 75ohm cables for the phasing harness in the 40m and possible 30m 4-Square array.

Individual Sponsors – 6m EME

The expedition is running two separate activities, with HF the main focus, and the second activity being 6m EME (which is possible mostly during week 1 only based on moon predictions). 6m EME has been especially requested as we have been told A3 has never been activated on 6m EME before. Getting the 6m EME antennas out to the island has proved a serious logistical challenge. Through the generosity of individual donors the 6m EME project is now possible and arrangements to freight the antennas and masts are now underway (after some more testing back in VK).

So, a huge thank you to the following who are supporting our 6m EME activities:

SP3RNZ, NJ6P, K2ZD, N3XX, G8BCG, SP4MPB, W6UC, K7CW, G8VR, SP7VC, N8RR, OH2BC, F6BKI, ON4IQ, ON4GG, N1DG, DL8YHR, ZS4TX, OH7KM, N7IP

See you all from Tonga in September!