Licenced Since


How you started

As a child electronics fascinated me. Back then it was valves, and I built many things, starting with a single tube audio amplifier (I think ECL86), test instruments eg VTVM, GDO, and even an oscilloscope using a VCR139a.

By age of 16, I was already dabbling in RF transmitters and did transmit illegally then - but just testing and to see how far my signal would go.

My dream was to be a licensed radio amateur. But then university and work got in the way, and just never got to it until 2020, when I said enough is enough - write the exam and get my license!

Most Memorable Contact

Hard to say, lately more JS8CALL than SSB, but with my 5w on JS8CALL, I regularly have QSOs with USA and Australia. With QO-100, my farthest was in Russia.

Best part of the Hobby

The electronics of it - so I enjoy building, even if it is a kit - but then one still has to wind toroids etc - see my photo of building the WSPR beacon.

Favorite Modes


About Stewart

I have a maths and physics background, but also majored in computer science, which just took over my life.

In those days it was the mainframe, for me the IBM 360/50. I got to know this beast inside out down to the extent of writing low level channel programs to control i/o devices. All in ASM of course.

Fast forward to today, my interests and hobbies include the following:-

  • Photography - use Canon equipment and “process” all my photos in Lightroom - enjoy scenic, wildlife (especially bird photography), astro, and street photography.

  • Hiking - belong to the JHB hiking club and try to hike every Wednesday with them. However, I have also done a number of more serious hikes, eg Kilimanjaro, Rwenzori (Uganda), and Towerkop.

  • Camping - enjoy our offroad camper to go anyway - just park off in the bush, throw up an EFHW antenna into a nearby tree and try some QRP with my G90.

  • Raspberry Pi - what a great gadget. I have written many systems using R-Pi (building water usage monitoring, load control of resorts, etc), not to mention usage in home media centre and in radio - eg JS8CALL coupled to a QRP labs QDX radio.

  • Amatuer radio - have become focused on QRP for SSB and digital modes especially JS8CALL., and WSPR (beacon and RX).

  • QO-100 - more recently I have ventured into satellite - but just NB SSB so far. My earth station uses a Pluto SDR for RX/TX with a small 10 watt linear. See the photo of my dish with a home built TX antenna (POTY). My goal is to get onto WB which allows me to RX/TX DATV - but later.

  • QRP Labs U4B - a balloon Tracker- this little guy is completely programmable with a built in GPS module. I have made one flight so far - BACAR (Oct 2023) from Secunda Airfield. I configured it to TX WSPR packets on 20m. TX power is just 27mw - but managed to be picked up in Brazil! My goal is to launch a pico balloon which circumnavigates the earth.