Finally I made it: my first ever qso in CW via satellite (RS-44). As I only have a free open view of less than 90 deg from my balcony, I have to wait for the right passes, and the time window is usually maximum 10 min.
Using the IC-9700 with the 5 element log. per. antenna on my home brew az/el rotator, I was able to hear my own CW signal from the satellite and manage a qso with E21EJC in Thailand!
Software is Gpredict with Hamlib running on my Mac.
For my VHF/UHF station I am using a dual band five element log-per antenna, similar to the Elk log-per. It is actually an ideal antenna for portable use, as it can be assembled and disassembled easily and packed in a small size. Now the idea came up to use it for satellite communication with my FT-818. The only thing missing was a azimuth/elevation rotator to track the satellites.
I started with my own design, using a stepper motor for azimuth and a servo for elevation. After a while I cancelled the project, as I had too many problems with electromagnetic interference to the servo.
Approximately a year ago I finally spent the money and bought a 3D printer. My main motivation was that I don’t have a workshop, and therefore I was not able to do even small mechanical things. I decided for the Creality Enders 3 Pro, as this printer has a large community, and it is easy to find tutorials and tons of other information on the web.
For the CAD program I ended up with Blender. It might sound like an overkill, but it’s open source and runs under Windows, Linux and Mac. Blender was the main hurdle, to get active with own designs, as it took quite a while to get familiar with the program using it for precision design.
From then onward, I have realized so many things using the 3D printer, and I can no longer imagine the hobby without this tool. Most items are printed with PETG.
The results are out! The first time I participated in the CQ world wide DX contest from Singapore. 167 contacts, 25 zones, 38 countries with 16.1 hrs operation gave me 22365 points. All with my 5 m whip antenna from the balcony and low power of 100 W.
A couple of weeks ago I started to gather my first experiences with software defined radios (SDR) and active antennas. I started with low investment, using the RTL SDR dongle, but I quickly realized that using the direct sampling mode for HF is not an ideal solution and added the Spyverter HF up-converter.
For my first trials I used a Mini Whip from RA0SMS as antenna, but the results were quite disappointing.
Finally, I ended up with an active loop antenna (see featured image), using the Cross-country Wireless Loop antenna pre-amplifier (10 kHz to 30 MHz version). The pre-amplifier is powered with 13.8 V via a bias-tee. Common mode chokes on the antenna line and all power lines helped to reduce noise, especially on the low bands. This is final hardware setup setup:
The setup is now running 24/7 on a Raspberry Pi 3B+ using GQRX and WSJT-X. I was surprised, how many stations and countries can be decoded down to 80 and 160 m.
Today I tested the first time my new solar power setup for portable operations. I am using a 60 W PowerFilm foldable solar panel and a 5 A MPPT charge controller for a LiFePo4 4S battery. The whole weight is 1600 g including the 5 m connection cable.
It was cloudy day and the sun was most often covered by clouds. The panel is only exposed to 1/3 up to max. 1/2 to the full sunlight, if it is there.
Using a power analyzer, the data show a 1.4 A peak current and 19 W peak power. I was able to charge 10 Wh in about 2 hours. Next time I will try to get the panel under full illumination in the sun and measure again.
The analyzer shows current, voltage and power and in addition peak values for current and power as well as total energy (power integrated over time) in Wh.