My first QSO via Satellite

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.

sat-qso
Setup on the balcony

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.

QSO on minute 6:37

Mini Satellite Antenna Rotator MK1

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.

Searching for an alternative DIY solution, I came across the SARCNET website, and the mini satellite antenna rotator MK1.

I decided to build it, but to separate motors and electronics; purchased the parts and started the 3D print design. Below the details and the final result.

Overview of all 3D printed parts

When I first time applied power to the motor drivers, the following happened with a loud bang! Luckily, it was outdoor on my balcony.

Exploded capacitor ...
The 100 uF capacitor was faulty, this is the result after applying 12 V to the board.

My thanks to SARCNET, the software works w/o problems. I only had another EMI problem, which could be solved finding a well screened micro USB cable and adding a few ferrites.

3D Printing for Ham Radio

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.

Links

Drill press: https://www.thingiverse.com/thing:1642711/files

Rod and pipe cutter: https://www.thingiverse.com/thing:3323294

FT-60 radio mount: https://www.thingiverse.com/thing:979456