Sundog oor Kroonstad

“Sundog” verskynsel oor Kroonstad op 2018/11/02 om +-15:00…davdav

Secundaweather supports local solar power installation

Secundaweather is providing local weather data to Romano Solar, a prominent solar power solution provider.  In return, Romano Solar sponsored microwave amateur radio equipment to the Secunda Amateur Radio Club. All the equipment is now installed & operational.


System changes & maintenance for the next few months

I will be doing very much needed maintenance to the whole weather station system in the coming months.  Certain functions may be interrupted from time to time, including web page updates.

This will be the largest upgrade done on the system since the initial installation & configuration 6 to 9  years ago.

Some important items on the upgrade planning list:

  • Perform backups of applications and archiving of data
  • Upgrading operating systems on the weather system servers
  • Configuring stable virtual servers which can be easily recovered in case of failure
  • Re-evaluation of weather station functions/features based on web analytics information
  • Transferring & upgrading of applications and legacy data to the new virtual servers
  • Re-design of the main web page – the goal is to have one page suitable for desktops as well as mobile devices

Please be patient when the web pages are not updating as usual.  The upgrades are done to ensure availability for the next few years.   I hope to be done with it all by spring.



BACAR 5 – Successful High Altitude Balloon Flight

The Secunda Amateur Radio Club (ZS6SRC) launched the BACAR 5 high altitude balloon on Saturday 21 October.  BACAR is the acronymn for BAlloon Carrying Amateur Radio.

The BACAR project is a STEM (Science/Technology/Engineering/Mathematics) educational initiative, being run by the Secunda Amateur Radio Club.  This is the fifth year of the project.  Schools are taking part by assembling experiments which fly on the the balloon mission. After a succesfull recovery of the various payloads attached to the balloon, experiment results can be downloaded and processed.

The primary mission objective was surely achieved: giving learners an opportunity to take part in a STEM project, maybe planting the seeds for choosing a career in science or engineering!

Some highlights on launch day:

Preparations for launch under way





Members of the AMSAt SA Kletskous cubesat development team

Members of the AMSAt SA Kletskous cubesat development team



We have liftoff!


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Some amazing views of Earth on the way up

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At an altitude of 29.5 km the balloon burst.


 Some more awesome views coming down:

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After a few minutes the payloads were on solid ground and waiting to be recovered.


Watch one of the videos recorded during the flight:

And some flight statistics:



Typical conditions for September

Typical conditions for September, calculated from weather station data 2009. – 2016






Spaceweather: Solar Flare from Sunspot 2673

Sunspot 2673 unleashed an X-class solar flare earlier today, causing some radio blackouts on the sun facing side of earth.

Some images from NASA/NOAA:

mdi_sunspots goes-xray-flux radio latest


DIY – Stir Plate for Brewing Yeast Preparation

So, after watching a few online videos, I decided to build my own stir plate for brewing yeast preparation.

I am sharing this easy and cheap construction method, because it is so simple and easy to build and it works really well!

Step 1 – the parts

– An old PC fan (or a new fan, seeing that they are so cheap)


– Some small disk magnets (see photo of fan)

– An old USB cable to supply power to the fan.  you can plug this into a cellphone charger or pc or whatever you have


– Erlenmeyer Flask to prepare your yeast in


– Stir bar – I used a “Bucky Bar” to test with as I have not yet received my real stir bar in the post

IMG_8666_stir bar

– Plastic lunch box, large enough to fit the fan in and large enough to serve as a base to put the flask on


Step 2 – Assembly of the components

– Glue two magnets onto the rotor of the fan, ensuring that opposite polarities are facing upwards

– Center the fan on the lunch box and mark the mounting positions on the lunch box.  I used a drill to mark the hole positions.


– Drill the mounting holes and mount the fan. Try to mount the fan as close as possible to the lid, without any moving parts touching the lid.


– Solder the fan wires to the power wires of the USB cable and tie it down to make it look better.



Step 3 – All done, now it is time to test

– The completed project


-Testing –  The small magnetic bar draws a nice vortex down to the bottom of the flask.



Botswana Earthquake detected by the seismometer

Earthquake detected by my seismometer, all info points to a 6.8 quake in nearby Botswana


Amateur Radio Astronomy


Solar Storm Forecast: 2017-03-23


SDR: the basics of IQ signals, modulation and demodulation

Part 1:


Part 2:


STEM: Energy, Entropy , a must see video

This is an excellent video on energy, entropy, heat, order, and disorder in the world we live in


Cyclone Dineo – Satellite Image, Thermal Enhancement

Satellite Image - Thermal Enhancement: Cyclone Dineo over Mozambique

AMSAT SA Workshop held at NARC

A very successful SDR (Software Defined Radio) workshop was held on Saturday 26 November at the National Amateur Radio Centre (NARC).  Software defined radio concepts are already in widespread use in the telecoms industry and is spreading out into other radio communication domains.

Two presentations on SDR Fundamentals and a concept SDR based Satellite Transponder were done by Anton Janovski (ZR6AIC) and Cor Rademeyer (ZS6CR).

More information will be posted on the AMSAT SA website.

img_3331_img_3325_ img_3333_Photo credit: Hans van de Groenendaal


Secunda Beer Brewers Group – Beer Tasting 2016/11/12

The Secunda Beer Brewers Group held a beer tasting event, here is the results and some photos.

AMSAT SA – SDR Workshop


Graphs: Temp & Humidity mirror images

Last two days had nice mirror profile temperature and humidity graphs:

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Satellite Image: EUMETSAT RGB


EUMETSAT Satellite Image – RGB


Precipitation Forecast

Precipitation Forecast Animation

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