9V1KG – DU1KG – 4E1A
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.
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.
When I first time applied power to the motor drivers, the following happened with a loud bang! Luckily, it was outdoor on my balcony.
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.
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.
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
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.
Talk given during SARTS monthly meeting
PSK reporter link to stations currently received by 9V1KG
CQ WPX over … stn closed. Poor propagation, could not improve from last year. But 850 qso and 700k points in low power is also not bad. 🙂 4E1A
Last weekend I participated in the CQWW DX contest SSB part under the call sign 4E1A. Propagation was miserable on 40 m and 80 m; with my 100 W low power I was seldom heard by DX stations in EU or NA. On 20 m and 15 m propagation was acceptable, and I got even some openings on 10 m. Finally, I could exceed my points from 2018 and made 852 contacts with 62 DXCC entities and in 30 zones.
Raw score: 2287 QSOs x 191 multipliers = 436817 points.
Presentation of my FT-818 go kit and portable operation to Coron, Palawan on the February SARTS monthly meeting.
Surprise in the mail: plaque for CQ WPX CW contest 2018
Finished the setup of my portable station. All components are mounted together using maker beam profiles: FT-818, PA MX-P50M, ATM Z817, Solar charge controller and Computer interface.
