AMSAT SA

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  Space Symposium 2018

 

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The AMSAT SA Space Symposium was held on 19 May 2018 at the Innovation Hub in Pretoria.

As papers become available for publication you can download them from this page. If you did not attended the space symposium, you are free to download the papers but we request you to make a donation to AMSAT SA.  Our bank is ABSA, Branch code 632 005 Account number 40 8982 6281. Please send an EFT advice to admin@amsatsa.org.za so we can acknowledge receipt. Thank you for your support.


Es’Hail-2: An Updated Look at Amateur Radio’s first Geostationary Satellite

Author: Hannes Coetzee, ZS6BZP, B.Eng. Electronics (Pretoria), M.Sc. Space Physics (Rhodes)

If all goes according to plan the Qatar Satellite Company’s second satellite, Es’Hail-2, will be placed in a geostationary orbit by a Space-X Falcon-9 rocket within the next year. It will carry an AMSAT linear transponder as a secondary payload, giving amateurs for the first time access to a geostationary satellite. The transponder uplink frequency will be 2.4 GHz, downlink frequency 10.489 GHz and the bandwidth 250 kHz.

The operational parameters of the transponder are analysed and possible technical solutions for the up- and downlink requirements are presented. Emphasis is placed on low cost equipment in the best Ham tradition.

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KLETSKOUS CubeSat Project

Author: Hannes Coetzee, ZS6BZP, B.Eng. Electronics (Pretoria), M.Sc. Space Physics (Rhodes)

SA AMSAT has decided to embark on the development and launching of a South African Amateur satellite. The satellite will be based on the CubeSat principle. The subject of this paper will be a basic satellite with a short time to launch.

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UADC4 - Universal Analog to Digital Converter for Zero IF Software Defined Radios

Zero IF receivers or Direct Conversion Receivers (like softrocks, IQ mixers, WSE converters and IQ+ receivers) are the most popular SDR implementations used by Ham Radio operators after the Super Heterodyne Receivers.

Alex Artieda   ZS6EME (HB9DRI)

The introduction of PC audio sound cards creates an extensive platform for experimentation of which Ham Radio operators have profited in an incredible way for more than 25 years. But as usual, performance is a strong tradeoff negotiation; where the new PC audio cards cannot add more performance in our SDR RX systems, the answer is very simple.

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A BACAR-ready 10 GHz beacon to exercise your Es’hail-2 receiver

Author: Hannes Coetzee, ZS6BZP, B.Eng. Electronics (Pretoria), M.Sc. Space Physics (Rhodes)

If all goes according to plan the Qatar Satellite Company (Es’hailSat) will place its second satellite, Es’hail-2, in a geostationary orbit with the help of a Space-X Falcon-9 rocket. This will hopefully happen before the end of 2018. Es’hail-2 will carry an AMSAT linear transponder as a secondary payload, giving amateurs for the first time access to a geostationary satellite. The launch was originally planned for the second half of 2016 but has since been postpone numerous times. Some radio amateurs have already built receivers for Es’hail-2’s X-band downlink but aren’t able to test them as there are not any suitable beacons on the air.

A 10 GHz beacon implemented as a Balloon Carrying Amateur Radio (BACAR) payload will be very handy in this respect and will also offer radio amateurs the opportunity to join the BACAR fun.

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Board interconnection for integration measurements and stabilising the EPS output

Author: Fritz Sutherland Jnr (ZS6FSJ)

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.

On the second prototype the battery was changed to a Lithium Iron Phosphate (LiFePO4) battery, also called a LiFe battery, because of the fire and explosion hazards associated with Lithium Polymer batteries. This meant that the charge controller also needed changing to the LT3652 which can charge a LiFe battery. On the second prototype the PC104 interface was also added so that the boards of the various satellite sub-systems can be interconnected.

The third prototype conformed to the agreed common PCB outline for the satellite. A constant current source to drive the 0.2 mm NiChrome heat-wire for the release mechanism was added along with a mechanism to activate it from the controller board. A couple of field effect transistors (FETs) were also added to allow for single pole switches to be used for the launch switch and the remove-before-flight switch.

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BACAR - Qua Vadis

Author: Christo Kriek ZR6LJK

Download PowerPoint here


FUNCube and its data and some hidden secrets

Author: Deon Coetzee ZR1DE

Download PowerPoint here


A Mission and Quality Assurance Perspective on Radio Amateur CubeSat’s

Author: Nico van Rensburg ZS6QL

There is a false impression and a fabricated perception that building, launching, deploying and operating a CubeSat is easy, a proverbial walk in the park and that any person or institution can achieve it. This fabricated view of designing, building and deploying an amateur radio CubeSat is completely false and incorrect. It takes a dedicated team of technical talented individuals following an appropriate planning and execution process to accomplish it.

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More papers will be added soon.