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Weekly satellite report

1 October  2017


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 SA AMSAT embarked on the development and launching of a South African Amateur satellite. The satellite is based on the CubeSat principle.


What is in the July Edition:

The challenges of developing a linear transponder

Leon Lessing ZS6LMG

Also read:

Very Large Survey Telescope Captures Three-In-One

Learners to explore near-space with SANSA and Amateur Radio

Italians launch 3U CubeSat

New Chinese amateur satellites

SDR workshop 19 August 2017


To request a trial copy send your email address here with trial copy in the subject line



Kletskous Transponder to fly on BACAR

The Kletskous transponder will fly in near space on BACAR on 21 October 2017.

The transponder will operate on the following frequency

Uplink:     435.145 MHz  NBFM

Downlink: 145.870 MHz NBFM

Maximum uplink power is 5 watt EIRP.


Kletskous with transponder fitted. Photo by ZS6LMG

Hannes Coetzee ZS6BZP fitting panels into the new space frame with Frik Wolff ZS6FZ lending a hand.

The transponder is linear and will accept both FM and SSB. Please use low power to avoid swamping the receiver.  In addition to the transponder  the Kletskous payload will include the stabilisation board and the electronic power system (EPS) as well as the OBC.



Kletskous is crowd funded. Please make a contribution to the Kletskous fund. The account number is ABSA 40 8982 6281 Branch code 632 005. please send payment advice to,za with your details so that your name can be added to the donor list on the web.



For more details about Kletskous  listen to Hannes Coetzee here

Kletskous transponder V3 demonstrated

Leon Lessing, ZS6LMG  successfully demonstrated the version 3 of the Kletskous transponder at the AMSATSA/SARL SDR workshop held on 19 August 2017

Watch it here


Speaking at the AMSAT SA Space Symposium  held on 27 May at the Innovation Hub Hannes Coetzee said that good progress has been made on KLETSKOUS.

The University of Stellenbosch has come on-board and the optimization of the space frame was addressed by a mechanical engineering student, Francois Oberholzer. Francois is now busy with post graduate studies and manufactured a prototype of this optimised design.

 Hannes Coetzee admiring the new Space frame developed  by Francois Oberholzer (left), based on the Deon Coetzee ZS1DE original design,  with Fritz Sutherland jr ZS6FSJ

Deon Coetzee is developing the mounting and deployment mechanisms for the antennas as well as for the multiple solar panels on KLETSKOUS.

A Command Link will be required for housekeeping purposes and also maybe for in-flight reprogramming of the onboard controller, although this is risky business as the satellite may be killed if the reprogramming is unsuccessful. The best option would be to launch the satellite with flawless software already loaded, if at all possible. 

A Scheduler will switch the transponder on and off at pre-determined times. These times will correlate to certain areas being over flown by the satellite. It will be possible to set the onboard clock of the Controller to ensure that the Scheduler performs correctly. 

A Telemetry Downlink will be required. Some of the parameters that must be monitored on the ground include battery voltage and temperatures, orientation of the satellite via the radiation sensors in the centres of the five solar panels and the output voltages of the solar panels. It is planned that the Command and Telemetry functions be based on those implemented on the High Altitude Balloon Experiment, HABEX. All the above functionality is under the control of the OBC. 

The third prototype On Board Controller (OBC) has been completed and the house keeping software is currently being developed and tested by Brian McKenzie.


Electric Power System (EPS)

Fritz Sutherland jnr. is developing the EPS for KLETSKOUS. The third prototype of the EPS is performing very well. Use is made of a new generation, high power density LiFe battery. Integration with the OBC has also commenced.

In the photograph: Fritz Sutherland explains the PSU to Francois Oberholzer with Frik Wolff ZS6FZ looking on.

It will be difficult to implement active stabilisation in a 1U package together with the transponder required for the main payload. A passive (magnetic) stabiliser should keep the antennas adequately orientated during a pass over Southern Africa. This is also the solution implemented on FunCube. Frik Wolff, ZS6FZ, has made very good progress with the development of the passive stabiliser. A form, fit and function version is ready for integration with the rest of KLETSKOUS.

The prototype, 2m and 70cm crossed dipoles are performing well, even in close proximity to the space frame.


Leon, ZS6LMG, has taken over the development of the transponder. The first prototype transponder has been repaired after it was damaged by a power supply problem. Integration between the transponder and the On Board Controller (OBC) has been started. The command link and telemetry downlink are being addressed. Lessons learned and updates required will be implemented on the next prototype that is due soon.

For the full document presented at the space symposium download here.

Getting ready for Amateur Radio’s first geostationary satellite

Find out more at the AMSATSA Space Symposium how easy it is to get up and running

Download brochure here

If all goes according to plan the Qatar Satellite Company’s second satellite, Es’hailSat-2, will be placed in a geostationary orbit by a Space-X Falcon-9 rocket in the third quarter 2017. The Qatar Amateur Radio Society (QARS) managed to secure the privilege to have an Amateur Radio payload as part of Es’hailSat-2. Discussions regarding the payload were held with experts from AMSAT-DL, AMSAT-OH and AMSAT-UK. 

In a paper presented at the 2016 AMSAT Space Symposium, Hannes Coetzee, ZS6BZP explained that the gain of an antenna on a geostationary satellite is limited by the area that needs to be covered (the satellite’s footprint). With too much gain the beam width becomes very narrow leading to areas not being illuminated by the antenna on the satellite. This is the case for spot beams. In order to cover all the visible Earth from geostationary orbit the beam width may not be less than 17.4° leading to a maximum gain of ~20 dB.  

Read the full article here and learn about an inexpensive way to set up a ground station.

AMSAT Kletskous transponder


Download the presentation (PDF)  here

Watch the video presentation by Jacques Roux here



Photo by ZR1DE


The electric power system (EPS) is the sub-system that provides the satellite with power. The sub-system started out as a set of specifications and requirements which evolved to a basic block diagram. From there a few simple conceptual experiments eventually led to the first prototype. The first prototype was based on 10 V (open-circuit) solar panels, a 2-cell lithium polymer battery and 2 switch mode step-down converters for 3.3 V and 5 V power conditioning. Taking the risk of fire or explosion was somewhat justified by the good energy to weight and power to weight ratio it offered. However, in the meantime a new battery technology has emerged from the laboratory stage to being (fairly) commonly available on the market. This new technology is the lithium iron phosphate (LiFePO4) battery. Also based on lithium it still offers a fairly high energy to weight but it is inherently much safer and has electrical characteristics that are very similar to the lithium polymer and lithium ion type batteries. Another advantage is the longer expected lifetime of the LiFePO4 battery.


An easy to operate satellite recently launched by AMSAT NA

Get all the details here

CPUT planning a successor to Africa’s first nanosatellite 

The Cape Peninsula University of Technology (CPUT) is planning a successor to its first CubeSat and has set it vision on ship-tracking. In a paper presented at the recent SAAMSAT space Symposium in Pretoria Daniel de Villiers, Development Engineer at French South African Institute of Technology (F’SATI)  at CUPT, said that  ZACube-2 will be the second satellite in F’SATI’s ZACube-I nanosatellite mission series. These missions are developed at the French South African Institute of Technology (F’SATI) and the Africa Space Innovation Centre (ASIC) at CPUT with funding principally from the Department of Science and Technology (DST) and the National Research Foundation (NRF). Development of some subsystems has been ongoing for a number of years and has yielded a suite of commercial CubeSat parts that is ready for use in the satellite.

Download the paper here


4 November 2017

The workshop presented by AMSATSA  will be held in Cape at the Cape Peninsula University of Technology (Bellville campus) on 4 November 2017.

Get more details and booking form here

Become a partner in space

Donate to the AMSAT SA Kletskous fund and become a partner in space

Please make your contribution. You may pay directly into our account electronically. Please send the payment details with your name, callsign, email and  postal address to

All contributions will be acknowledged on this page (Scroll down). Donations of R500 or more will be acknowledged with a certificate.

Bank Details: AMSAT SA, ABSA Menlyn, Branch code 632 005
Account: 40 8982 6281

African Radio Amateurs will soon have access to a geostationary satellite

In the next few years radio amateurs will have access to two geostationary platforms, one that will service the Americas and another one, particular attractive to South Africans, that will be  positioned at 26° East giving 24 hour access to Africa, Europe and the Middle East. These two geostationary projects will be included in commercial platforms similar to Amateur Radio Satellite (AMSAT) South Africa seeking to have an amateur radio transponder included in South Africa’s next satellite currently designated as EOS-1 (Earth Observation Satellite). Read the full story here



RS, the component supplier in South Africa has become a component sponsor for the KLETSkous project.

RS Components is the market leader in the high service level distribution of electrical, electronic, mechanical & industrial products as well as tools.  Offering over 400 000 products across 2000 leading brands at, RS serves every sector of industry in the procurement of their products relating to maintenance, repair, operations, low volume production, research and development.

TRAX SPONSOR PCBs for KLETSkous More about  TRAX

Avnet : a broad line supplier of semiconductors,  passives, magnetics, enclosures, optoelectronic, GPS / GSM, interconnect, electromechanical, embedded products and components

Deon Coetzee ZR1DE
Tobile Koni ZS6TKO
Jan van Rooyen ZR5JR
Pravin Ashok
Donald Jacobs ZS2BW
Ray Webber ZS6RSW
Tarries Brink  ZS6MNO*
Kempton Park  Amateur Radio Technical Society ZS6KTS
Paul Roos ZS6HQ*
Anton Janovsky ZR6AIC
Pine  Pienaar ZS6OB
Gert Botha ZS6GC
David Horne
Etienne Saayman ZS5EFS
Nic van Duffelen ZR6AEZ
Andre Rox ZS6ARX
Carl Wentzel ZS6CFW
Gert Kok
Gordon Prentice ZR6RA
Rassie Erasmus ZS1YT
Guy Eales ZS6GUY
Bert van der Ploeg ZS6VDP
Wally Watson
Rickus de Lange ZS4A
Kerverne Thurling ZS1ABU
Lem Melidonis ZS1LEM
Paul Johnson ZS1S
Martinus Grobbelaar
Michael Boast ZS5BGV

*Denotes  that the person has made several donations over time. Thank you