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.