When booking a trip to Iceland, the idea emerged to become QRV on some HF bands in digital modes using my (tr)uSDX. As I did not want to take excessive luggage with me, the precondition was that the additional equipment has to be as small as possible. After some investigation and experiments, the following setup was used.
The TRX was of course decided beforehand to be the (tr)uSDX with the high band option (20m and up) for the antenna not to be too large. It is powered by a powerbank capable of providing 12V via USB PD and the necessary trigger device.
The computer was also a simple decision: A Raspberry Pi 4 with 4GB of RAM with a small 3d-printed housing. It is powered from a different power bank directly with 5V via USB-C.
The hardest decision was the antenna, as antennas on the HF bands are typically large. In the end however, the decision was the obvious choice to use a linked end-fed antenna. It can be tuned by opening the respective connections. The center of the antenna is elevated with a telescopic fishing rod to about 4m height. Longer rods would of course be better but have a packed length that goes beyond the size of my suitcase. The connection between the TRX and the antenna is made using roughly 5m of Airborne 5 cable.
For display, I used my Android tablet that connected to the Raspberry Pi using VNC. Additionally, the tablet’s internal GPS receiver was used to provide the time reference for WSJT-X via an SNTP app. The necessary WiFi connection was established over an access point opened by the Raspberry Pi. This enables maximum flexibility and comfort by putting the equipment outside and operating the setup from the inside.
Preparation and Exercise
After everything was put together, I used a weekend trip to test the equipment under realistic conditions. The first test was conducted at the Illerursprung (Locator JN57dk). After calling CQ as DC6GF/P, I was a bit overwhelmed by the response and also by only being able to use the touch display. So sorry to all who received weird messages from me at that day! In the end six QSOs from a not so optimal location within a valley were a big success for me.
The next test was operating from nearby the Fellhorn summit (Locator JN57ci). There I struggled with difficult lighting conditions and usability issues of the VNC client together with the desktop environment that would switch to a different desktop when touching in the wrong place. Returning to the right desktop was unequally difficult. In the end I achieved only two QSOs.
The last test with a refined end-fed antenna was conducted directly from my garden. As everything worked well, this setup was the final one and could be packed for the trip to Iceland.
On the Air as TF/DC6GF
On Iceland, operation was planned from four different locations where we did not stay at a hotel but at cottages where there was some space outside to place the antenna. The locators I operated from were HP94sg (7th June 2023), IP25sg (11th and 12th June), IP05am (17th June), and HP85pa (18th and 19th June).
The number of QSOs varied strongly between 6 QSOs on two days from HP85, and 75 QSOs on two days from IP25. Highlights were some QSOs to Japan and Brazil. ODX was PY5EJ in GG54 with a distance of 10418km. Impressive how far 4W of RF power can go! Overall I achieved 107 QSOs (43 on 20m, 37 on 17m, and 27 on 15m) with 105 individuals from 27 DXCC entities. I put some overview graphs below. Please excuse the poor quality and German localization but I think the main information is visible.
Operating from not so usual locations proved to be a lot of fun and a great experience. So whenever the occasion comes up again, I will definitely try again.