Down Memory Lane: SARL National Convention 11-13 April 2008 held in Bloemfontein.

 

I had the opportunity to attend this years SARL National Convention in Bloemfontein. Those who did not attend........ too late now. Remember I told you not to miss this one.....sorry but you missed out big time!! I will not go into great detail regarding the decisions made at the convention but will provide you with some detail about some of the activities I attended over the weekend. From the outset I would like to point out that I did not attend the SARL Awards Dinner and the ZS9X Breakfast. Firstly I hate a tie and jacket (formal) affair and secondly do not believe in awarding radio amateurs on a nomination basis. This is not sour grapes. I will soon express my opinion regarding awards in the ZS1I Ramblings and Thoughts page. I could unfortunately not attend the ZS9X Breakfast due to other family commitments, but thanks to John ZS4S myself and Nico ZS4N was given a "private" tour of the facilities on the 17 April 2008. More info on this later. Enough rambling let's get to the SARL National Convention Program. It all started on Friday afternoon the 11 April 2008. The Repeater Link and Local Town Repeater came alive with "guests" arriving on a regular basis.

                                                  Friday evening 11 April 2008

                                           "A Feast of Stars"

First on the program was a visit to the Boyden Observatory home to the second largest telescope in South Africa. (the biggest one of course is at Sutherland) Boyden is one of South Africa's primary astronomical research centres and also operates a unique science communication program for the public and schools. Myself and Nico ZS4N left at 17h30 for the Boyden Observatory. On our arrival at 18h15 we were welcomed by members of the Bloemfontein Radio Amateur Club and Friends of Boyden. ( The Bloemfontein Branch of the Astronomical Society of South Africa)

Photo: Boyden Obervatory: Bloemfontein

Arriving radio amateurs gathered and met each other at the Science Centre. Those who arrived early had the opportunity to climb the auditorium roof and were awarded with the breathtaking sun-set view of Bloemfontein and surroundings. Another bonus was to view the planet Saturn through an 8 inch portable telescope. The" rings" around Saturn could clearly be seen. Some of us even had a second look through the telescope as this is something you definitely do not see every evening. We were treated with a bowl of very nice curry and rice for supper Being hot all-over we left the curry pots we left for the auditorium were we were welcomed and addressed by Gerhard Penning. He gave us an overview of the Boyden Observatory. The Auditorium (pictured building with step roof) was completed in 2004, with a donation from the Shuttleworth Foundation. It seats 100 people inside and can accommodate 200 people on its roof. The latter configuration is used for open sky presentations. The previous lecture hall (pictured lower right) is being transformed into a science exhibition area.

The inside of the auditorium is custom made for high-performance multi-media presentations. A large wall for digital projector shows ensures a visually stimulating experience for every audience. The excellent sound environment adds to the impact. The auditorium is used as Boyden's primary presentation facility.

Gerhard presented a 30 minute Multimedia presentation: Journey to the Stars which was in my opinion breath taking. During the presentation you could hear several "auws and aahs" when he made several comparisons and revealed the sizes of planets. Example the Star: Alpha Centourri is 4 light years from the sun and that our fastest satellite which travels at 70km's per second would not be able to reach the star in our life-time. After this presentation we again climbed the stepped roof of the Auditorium were several different stars was pointed out with a green laser and attendees was given the opportunity to view stars via the 8 inch Dobsonian telescope. We then visited several of the telescopes at Boyden and were given the opportunity to look through the 13 inch Alvin Clark Refractor Telescope. The 13" refractor is a remarkable telescope - it is over 110 years old, but is in top condition and its image clarity is any amateur astronomer's envy. Its adaptability for different eyepieces and photographic equipment is a great strength. The telescope has an 8 inch refractor mounted on it, an excellent telescope in own right. Two finders assist diligently.

The history of the telescope goes back to 1889. It was initially mounted at Mount Wilson (USA) and after about a year moved to the Harvard Southern Station in Peru. The 13" was also one of the first telescopes to move to Boyden Observatory near Bloemfontein. It did professional research during its existence both at Arequipa in Peru and at Boyden in Bloemfontein, South Africa. This concluded the "FEAST OF THE STARS". We left the Boyden Observatory just after 22h00 SAST with much more knowledge about stars, planets and the universe then before.

13 inch Alvin Clark Telescope

60 inch Rockefeller Telescope

Auditorium with step roof

Auditorium step roof at night

 

Saturday morning 12 April 2008

"A Feast of Decisions"

The AGM was held at the Little Willie Auditorium at the School of Armour in the Tempe Military Base, Bloemfontein. Myself and Nico ZS4N left Pellisier at 07h15 and arrived at the School of Armour round about 07h35. Radio Amateurs of the Bloemfontein Radio Amateur Club were just putting together the final touches while we had a splendid cup of coffee. While drinking coffee the socializing part of the meeting took place. I met Malcome and Shiela Kriel ZS4SM again after not having seen them in the last 15 years. We really had a great chat about the old days and it was good to see them although the years have moved on. Several vendors in Amateur Radio equipment proudly displayed the latest equipment and frantic questions were asked about several equipment. The vendors present were, Sam's Radio Accessories, Ham Radio Outlet - SA and Johan Lehman ZS6JPL. A special word of thanks to these vendors who displayed their equipment and made pamphlets of equipment available at the AGM. Johan ZS6JPL must also be thanked for sponsoring a Yaesu handheld, Yaesu caps and pens to members attending the AGM. Congratulations to the YL of Colin ZS6COL who won the Yaesu VX-120 handheld. Well let's get back to the "Feast of Decisions". Herewith a short summery of events:

7h30 - Registration

8h00 - Gathering in the Auditorium at the School of Armour, Bloemfontein

9h00 - Group Photo taken

9h30 - Dennis Green ZS4BS gives and overview of the School of Armour

9h38 - Graham Hartlett ZS6GJH (President) constitutes the AGM Agenda relating to apologies, Rules of Debate, Declaration of Quorum, Remembrance of Silent Keys and receive and approval of he 2007 AGM Minutes. He then provided his Presidents address and report where the following was revealed:

Current Membership total 1138

Average age of members 56.6 (came down by 1 year)

36 SARL members present with 171 proxy's. 7 above the required total to constitute the meeting. (This is quite alarming!!)

Need more SARL members

Bring youth into Amateur Radio

Need a Membership drive

Discussed the RAE, ZU Exam and RTA

Positive Finances

Current Bank Balance

Positive future

Thanks all Council Members

10h15 - Rassie Erasmus ZS1YT delivered the Treasurer's Report which revealed that the League's current financial status is healthy. Subscriptions for 2008/2009 will be R305.00 for ordinary members, if you pay within a prescribed period after receipt of your account. However if you fail to pay within this period you will have to pay the amount of R320.00.

10h55 - Graham Hartlett ZS6GJH Motions. There were only two motions. Motion 1 was lost after voting and Motion 2 was won after a unanomious decision.

11h25 - Election of Councillors. Graham ZS6GJH indicates that he will not be available for election to Council due to other commitments.

At the first council meeting following the 2008 AGM portfolios were allocated as follows:

Rassie Erasmus, ZS1YT - President and Treasurer;

Dennis Green, ZS4BS - Vice President and Radio ZS;

Henry Chamberlain, ZS1AAZ - Secretary;

Louw Erasmus, ZS6LME - Legal Advisor and Office Manager;

Hans van den Groenendaal, ZS6AKV - ICASA, Public relations;

Fred Scheepers, ZS1FCS - Education;

Mark Zank, ZS6YES - RAE;

Graham Butler, ZS1GVB - Advertising Manager;

Laurie Devereaux, ZS5DL - Minute Secretary and IARU Monitoring Service;

Malcolm Kriel, ZS4SM - STARS and Youth Development;

Ivan Newman, ZS1ILN - Membership and Website.

Francois Botha, ZS6BUU, was co-opted onto council with the portfolio of Hamnet and QSL Manager

The Appointees are:

George Honiball, ZS6NE - Bulletins;

Tjerk Lammers, ZS6P - Awards;

Richard Seddon, ZS2CLI - Website.

Congratulations to all those elected for 2008/2009.

12h15 - Confirmation of appointment: Honorary Auditor

12h25 - Any other business: 1. QSL Buro/Cards 2. Awards

12h40 - Date of next AGM and Venue: 18 April 2008 Cape Town

12h45 - AGM closing down.

Truely one of the shortest AGM's ever and really a pleasure to attend!!

Lunch was held at 13h00 where after I attended a Hamnet workshop presented by Francois ZS6BUU. Visit the Hamnet pages (click here)

 

Saturday evening 12 April 2008

"Feast of the Invited"

The SARL Awards Dinner was held at the restaurant on the historical Onze Rust farm, home of Colin and Jackie Steyn, South of Bloemfontein. As already indicated I did not attend the "Feast of the Invited". Unfortunately I cannot give and overview of the proceedings in this regard. However the SARL Bulletin provided readers and listeners with information relating to the events that took place Saturday evening. I will however express my opinion relating to the formal dress and awards by nominations under ZS1I Ramblings and Thoughts. Look out for this in the not to distant future.

 

Sunday 13 April 2008

"Breakfeast"

 

The SARL Convention closed with a breakfast at ZS9X, the contest station of the Bloemfontein Defence ARC on the Gen de Wet Training Area to the west of Bloemfontein. Unfortunately I could not attend the "Breakfast" due to family commitments, but visited ZS9X by special invitation on the 16 April 2008. Read more about my visit later on these pages.

Finally, a special word of thanks to all those who attended the SARL NATIONAL CONVENTION in Bloemfontein and a special word of thanks to Dennis ZS4BS and the Bloemfontein Radio Amateur Club for their hospitality and making this convention the most memorable in years. I really enjoyed being part of the group. Until next year............2009!!

Images:  Click on images for larger view

 

AllStar Experimentation - South Africa (Part 2)

In part 2 of AllStar Experimentation - South Africa I will publish how I succeeded in using the GPIO pins of the Raspberry Pi 3 b Ver 1.2 to key / PTT a transceiver using a 3.3 v Relay Module. 

This short manual discuss the method using the GPIO pins on the Rpi.

• to indicate TX / RX LED status on an AllStar Node

• to key PTT via a 3.3v Relay on an AllStar Node.

Warning: Ensure that you connect the LED’s to the correct pins. The GPIO pins are 3.3 volts maximum and output pins have a limited current capability of 16 mA. When interfacing be aware of this because you can damage the PI if you exceed the ratings!! I am not responsible if you damage or destroy your Raspberry Pi!!

I use a 2 Channel Relay - Module Opto Isolated 3.3V Logic 10A Load. See image below.

I highlighted the changes in black for keying the PTT Relay using the GPIO pins.

Go to and open MobaXterm

Check to see if the rc.allstar file is in /usr/local/etc/

cd /usr/local/etc

enter

ls or dir

enter

sudo nano rc.allstar

enter

File will open. Add bold typed info as listed below.

#########################################

#!/bin/bash

#

# This is the startup rc script for allstar asterisk

#

# Rather than changing anything here

# please use the /usr/local/etc/allstar.env file

# for configuration changes.

#Makes gpio pins go to output upon startup

/etc/asterisk/local/write_gpio.sh

# If root profile missing, replace it.

if [ ! -f /root/.bash_profile ] ; then

/usr/bin/cp -f /etc/.bash_profile.backup /root/.bash_profile

fi

# source the allstar variables

if [ -f /usr/local/etc/allstar.env ] ; then

. /usr/local/etc/allstar.env

else

echo " Unable to read /usr/local/etc/allstar.env file."

echo " Asterisk will not start"

exit 1

################################################

Once the bold info is entered

save

ctrl + x

yes

cd

enter

cd /etc/asterisk/local/

enter

sudo nano write_gpio.sh

then type the following script

####################################

#!/bin/bash

#script name - write_gpio

gpio mode 7 out ; makes gpio 7 pin 7 an output

gpio mode 2 out ; makes gpio 2 pin 13 an output

gpio mode 4 out ; makes gpio 4 pin 16 an output

#####################################

(Real Pin 7 = COS or RX node receiving voice from the Internet.)

(Real Pin 13 = TX or PTT node transmitting your voice into the Internet.)

(Real Pin 16 = PTT radio using 3.3 v Relay to key your radio transmitter.)

save

ctrl x yes enter

Check if write_gpio.sh file was created using ls enter or dir enter

Make write_gpio.sh file executable

chmod +x write_gpio.sh

cd

cd /etc/asterisk

enter

sudo nano rpt.conf

Under “Events” add the following:

########################################

; EVENTS

[events467652]

sudo /usr/local/sbin/7high.sh = s|t|RPT_TXKEYED

sudo /usr/local/sbin/7low.sh = s|f|RPT_TXKEYED

sudo /usr/local/sbin/2high.sh = s|t|RPT_RXKEYED

sudo /usr/local/sbin/2low.sh = s|f|RPT_RXKEYED

sudo /usr/local/sbin/4high.sh = s|f|RPT_TXKEYED

sudo /usr/local/sbin/4low.sh = s|t|RPT_TXKEYED

; Commands for FOB COS indicator when available

; For this to work you must also add - gpio4 = out,0 - to simpleusb.conf

; Uncomment (remove ;) on next two lines to activate

;cop,62,GPIO4:1 = c|t|RPT_RXKEYED

;cop,62,GPIO4:0 = c|f|RPT_RXKEYED

[events1999]

; FUNCTIONS

##########################################

save

ctrl x

Yes

enter

cd

cd /usr/local/sbin/

enter

Create 6 script files (Example: sudo nano 7high.sh enter)

7high.sh

7low.sh

2high.sh

2low.sh

4high.sh

4low.sh

In each script put:

 

7high.sh

#################

#!/bin/bash

gpio write 7 1

#################

7low.sh

#################

#!/bin/bash

gpio write 7 0

#################

2high.sh

#################

#!/bin/bash

gpio write 2 1

#################

2low.sh

#################

#!/bin/bash

gpio write 2 0

#################

4high.sh

#################

#!/bin/bash

gpio write 4 1

#################

4low.sh

#################

#!/bin/bash

gpio write 4 0

#################

save each one

ctrl x

Yes

enter

still in cd /usr/local/sbin/

make all 4 executable using the command

sudo chmod +x /usr/local/sbin/xxxxxx.sh

chmod +x 7high.sh

chmod +x 7low.sh

chmod +x 2high.sh

chmod +x 2low.sh

chmod +x 4high.sh

chmod +x 4low.sh

cd

sudo reboot

TX / RX LED’s and Relay PTT will now be working!!

Note: The one LED will light to show that the radioless node is receiving voice from the Internet. The other LED will light to show that the radioless node is transmitting your voice into the Internet. The LED on the relay board will light-up to indicate that the PTT is active.

Download Manual  HERE (PDF)

Recognition:  

AllStarLink Discussion Groups

HamVoip

Manual compiled by: 

Johan Terblanche ZS1I

Mossel Bay

Date: 24 February 2024

GPIO outlay diagram and photos related to the Raspberry Pi 3 B Ver 1.2 below as well as 2 x videos (in afrikaans) of the operational relay and connected radio:

 

A look at AllStar, Echolink, DMR, RF Repeaters, Links, Hubs, Nodes etc that constitutes the wide area ZS Network (Part 2)

Image: ZS1SB-L the Echolink Station of  Henry Hansen ZS1SB from Stilbaai

In this posting we are going to look at AllStar, Echolink, DMR Bridges, RF Repeaters, Links, Hubs, Nodes that are linked together to constitute an efficient and active South African Network for all radio amateurs to use.   The posting will be in several parts and will stretch over a period of time.  I would like to thank Henk ZS1AAD for gathering all the images and information and also every owner that provided  information about their station on request.  If you link to the ZS Network and you have not yet submitted images and information of your station,  please send it to me a.s.a.p. by clicking HERE  I would like to include all participating stations under this topic and publication.  Enough talk let's get going!!

The second station that we will be looking at is ZS1SB-L the Echolink Station of  Henry Hansen ZS1SB from Stilbaai which is linked to the 145.750 Mhz (CTCSS Tone 88.5 hz) Aasvoelkop Repeater situated near Albertinia in the Southern Cape.   

Click on images for larger view. 

 

AllStar Experimentation - South Africa (Part 1)

During the past month or two I was busy experimenting with AllStar.  Before I explain more lets find out what is AllStar in Amateur Radio?  

AllStarLink is a network of Amateur Radio repeaters, remote base stations, simplex radio links, Internet / Radio nodes and hot spots accessible to each other via Voice over Internet Protocol. AllStar runs on a dedicated computer (including the Raspberry Pi) that you host at your home, radio site, shack or computer center. It is based on the open source Asterisk PBX running our app_rpt application. App_rpt makes Asterisk a powerful system capable of controlling one or more radios. It provides linking of these radio "nodes" to other systems of similar construction anywhere in the world via VoIP.

AllStarLink's primary use is as a dedicated computer node wired to your repeater or radio. Connections from Echolink, other VoIP clients and telephone calls are supported.  Audio quality is way better than EchoLink or IRLP.

AllStarLink currently has 32,101 users and 32,010 nodes.  These figures increase on a daily basis.

As can be seen from the above AllStar is a very popular and useful "application" in Amateur Radio.

I started playing around with AllStar way back in August 2017. My first node 46765 was active and on the air in South Africa on Tuesday, 17 October 2017 at 15:14:36 PDT.  At the time only two nodes were active in South Africa.  One in Kwazulu Natal (Pietermaritzburg Repeater) and the other one in the Southern Cape (ZS1I GRHub Link). Since then several nodes were established one being the ZS1I DMR Bridge Node in Mossel Bay. It was one of the highlights as this introduced DMR for the first time to the Southern Cape area.

Let's get back to the latest experimentation.  Why experimenting further and what is there to experiment with?

I will try to explain.  My first node (GRHub Node) which is still active and on the air today was home built using a Raspberry Pi, Modified USB Soundcard Fob,  2 x Radios, Power Supply and LTE Internet Modem.  The USB Sound Fob was modified by me and in the process I destroying two USB soundcards.  The third modification was however successful.  Yep when you get older it is not easy to work with surface mount components especially if your eyesight is bad.  None the less the Raspberry Pi node has been running flawlessly since October 2017.

In the past few months several AllStar nodes were activated by fellow radio amateurs throughout South Africa at a very high cost.  During a technical discussion several radio amateurs indicated that they cannot pay the absorbent price for an AllStar interface (imported from overseas) nor do they wish to modify a USB Soundcard using either the CM108 or CM119 which must also be imported from overseas.  Now with the Rand / Dollar you can calculate the purchase-,  import- and tax costs.  Comes to a pretty penny for some of us. This set me thinking.  Why can one not use a cheap USB Soundcard even if the 48 pin surface mount IC has been covered with a black blob of nasty gunk.  I was thinking in the line of using the GPIO Pins on the Raspberry Pi for LED indication, PTT and COR.  After searching over several periods for several days it was clear that there is no support or very little information in this regard.  To cut it short, many pages I visited makes it very clear that this function will not be included in HamVoip or AllStarLink.

I find it quite strange but none the less an alternative for this is to use SVXLink which fully support the use of the GPIO pins.   Back to AllStar.  I am no programmer or a Linux Guru.  With the little bit of knowledge that I have I decided to experiment by using the GPIO pins of a Raspberry Pi to talk to AllStar and hopefully get everything to work without having to modify a USB Soundcard.

Now what follows, also in future postings is my humble experimentation looking at different ways and means to use the Raspberry Pi GPIO pins to perform several tasks while using AllStar. (HamVoip)  Please note that I am not the creator/writer of the code listed. I used bits and pieces from several sources which I combined that resulted in certain events / functions to be activated. There will be several parts posted under this topic which will explain how I hopefully succeeded in getting the following to work:

• Using Raspberry Pi GPIO pins to indicate TX / RX LED status on a Radioless (RFless) node. (Tested Working 100 %)
  
• Using Raspberry Pi GPIO pins to PTT a radio transceiver using a 3.3v Relay Module. (Tested Working 100 %)
• Using Raspberry Pi GPIO pins to PTT a radio tranceiver using an Opto Coupler Circuit (Tested Working 100 %)
• Using Raspberry Pi GPIO pins to activate COS (Work in progress)
• Combining a Radioless Node with a normal RF Radio Node using either a relay module or Opto Coupler circuit with COS (Work in progress)

The first three methods were successful using a Raspberry Pi 3 b Ver 1.2 and HamVoip.  It took a fair bit of time to make it work.  Let us see if I can get the last two to also work flawlessly.

For those that are interested I will post the code that I used to get the TX / RX LED status up and running below.  I will also post a link to the PDF file where the code can be downloaded. As always there is another way to achieve the same result but I chose this method as in future postings it will become clear why I chose this method. 

A special word of recognition to:

• AllStarLink Discussion Groups
• Brett ??? 
• Jeff Tranter
• French Open Networks F1TZO
• 4-Ham Radio Groups
• Open Repeater
• Raspberry Pi UK
• Internet Resources
  

                                                  ################################

TX/RX STATUS LED’S = RADIOLESS ALLSTAR NODE OR ANY OTHER ALLSTAR NODE USING A RASPBERRY PI 3 B V1.2

Warning:  Ensure that you connect the LED’s to the correct pins. The GPIO pins are 3.3 volts maximum and output pins have a limited current capability of 16 mA. When interfacing be aware of this because you can damage the PI if you exceed the ratings!! I am not responsible if you damage or destroy your Raspberry Pi!!

This short manual discuss the method using the GPIO pins on the Rpi to send a TX and RX status to two LED’s using a Raspberry Pi 3 b Ver1.2.

Note: The one LED will light to show that the radioless node is receiving voice from the Internet. The other LED will light to show that the radioless node is transmitting your voice into the Internet.

 

Go to and open MobaXterm

Check to see if the rc.allstar file is in /usr/local/etc/

cd /usr/local/etc

enter

ls or dir

enter

sudo nano rc.allstar

enter

File will open. Add bold typed info as listed below.

#########################################

#!/bin/bash

#

# This is the startup rc script for allstar asterisk

#

# Rather than changing anything here

# please use the /usr/local/etc/allstar.env file

# for configuration changes.

#Makes gpio pins go to output upon startup

/etc/asterisk/local/write_gpio.sh

# If root profile missing, replace it.

if [ ! -f /root/.bash_profile ] ; then

/usr/bin/cp -f /etc/.bash_profile.backup /root/.bash_profile

fi

# source the allstar variables

if [ -f /usr/local/etc/allstar.env ] ; then

. /usr/local/etc/allstar.env

else

echo " Unable to read /usr/local/etc/allstar.env file."

echo " Asterisk will not start"

exit 1

################################################

Once the bold info is entered

save

ctrl + x

yes

cd

enter

cd /etc/asterisk/local/

enter

sudo nano write_gpio.sh

then type the following script

####################################

#!/bin/bash

#script name - write_gpio

gpio mode 7 out ; makes gpio 7 pin 7 an output

gpio mode 2 out ; makes gpio 2 pin 13 an output

#####################################

save

ctrl x yes enter

Check if write_gpio.sh file was created using ls enter or dir enter

Make write_gpio.sh file executable

chmod +x write_gpio.sh

cd

cd /etc/asterisk

enter

sudo nano rpt.conf

Under “Events” add the following:

########################################

; EVENTS

[events467652]

sudo /usr/local/sbin/7high.sh = s|t|RPT_TXKEYED

sudo /usr/local/sbin/7low.sh = s|f|RPT_TXKEYED

sudo /usr/local/sbin/2high.sh = s|t|RPT_RXKEYED

sudo /usr/local/sbin/2low.sh = s|f|RPT_RXKEYED

; Commands for FOB COS indicator when available

; For this to work you must also add - gpio4 = out,0 - to simpleusb.conf

; Uncomment (remove ;) on next two lines to activate

;cop,62,GPIO4:1 = c|t|RPT_RXKEYED

;cop,62,GPIO4:0 = c|f|RPT_RXKEYED

[events1999]

; FUNCTIONS

##########################################

save

ctrl x

Yes

enter

cd

cd /usr/local/sbin/

enter

Create 6 script files (Example: sudo nano 7high.sh enter)

7high.sh

7low.sh

2high.sh

2low.sh

In each script put:

7high.sh

#################

#!/bin/bash

gpio write 7 1

#################

7low.sh

#################

#!/bin/bash

gpio write 7 0

#################

2high.sh

#################

#!/bin/bash

gpio write 2 1

#################

2low.sh

#################

#!/bin/bash

gpio write 2 0

#################

save each one

ctrl x

Yes

enter

still in cd /usr/local/sbin/

make all 4 executable using the command

sudo chmod +x /usr/local/sbin/xxxxxx.sh

chmod +x 7high.sh

chmod +x 7low.sh

chmod +x 2high.sh

chmod +x 2low.sh

cd

sudo reboot

TX / RX LED’s will now be working!!

In a future posting I will include videos showing how the events /functions operate.

Recognition:  

AllStarLink Discussion Groups

HamVoip 

Download Manual  HERE (PDF)

 

Manual compiled by: 

Johan Terblanche ZS1I  

Mossel Bay

Date: 24 February 2024

                                               ###############################

Images:  Click on images for large view.

      

   

                       

"Down Memory Lane" - SunSat Suid Afrika se Satelliet 25 jaar later nogsteeds in die Ruimte

(Foto krediet: Stellenbosch Universiteit)

Tydens vanoggend (25 Februarie 2024)  se SARL Bulletin is daar melding gemaak van die herdenking van Suid Africa se eerste minatuur satelliet bekend as SunSat.  Dadelik het dit tot my gedagtes gekom wat 'n wonderlike bebeurtenis was dit nie.  Nie net vir Amateur Radio of die Universiteit van Stellenbosch nie, maar ook vir  die hele Suid Afrika. 

Die Universiteit van Stellenbosch se SUNSAT was die eerste satelliet wat in Suid-Afrika ontwerp en vervaardig is. Dit is op 23 Februarie 1999 aan boord van 'n Delta II-vuurpyl vanaf die Vandenberg-lugmagbasis gelanseer om die eerste gelanseerde Suid-Afrikaanse satelliet te word. Sunsat is gebou deur nagraadse ingenieurstudente aan die Universiteit van Stellenbosch. Sy AMSAT-benaming was SO-35 (Sunsat Oscar 35).

Luister gerus na die klank insetsel waarin Sias Mostert meer vertel van SunSat.  In dieselfde denke is daar ook die groot hartseer dan ons deesdae in Suid Afrika die verlede herdenk (niks verkeerd daarmee nie) wat tegnologie aan betref.  Ja daar was nog 'n Suid Afrikaanse satelliet gelanseer met die naam van Sumbandile Satelliet.  Ongelukkig was daar so hier en daar probleme ervaar met die spesifieke satelliet.  Nou wat het sedert die landsering van Sumbandile gebeur op die satelliet front in Suid Afrika.  Ja ek weet dat van die tegnologie wat ontwikkel was 'n tuiste gevind het in ander lande onder andere uitstekende kamera tegnologie.  Daar is ook al etlike jare sprake van 'n nano satelliet wat eendag hopelik sy tuiste in die ruimte sal vind.  Ek is ook bewus dat Suid Afrika van ons buurlande behulpsaam was/is tov satelliet vervaardiging en tegnologie 

(Foto krediet: Stellenbosch Universiteit)

Daar blyk maar deesdae 'n groot droogte te wees tov die landsering van Suid Afrikaanse satelliete. Die hartseer deesdae is dat in Suid Afrika die verlede herdenk word in stede daarvan dat nuwe satelliete gebou word.  Een troos is dat daar verskeie privaat Suid Afrikaanse maatskappye is wat satelliet toerusting vervaardig en steeds aan die voorpunt bly van die nuutste satelliet tegnologie.  Ja ek weet daar is so hier en daar vordering tov komponente/onderdele ens. maar op die stadium blyk daar nie 'n dringendheid om plaaslike vervaardigde satelliete die ruimte in te stuur nie.  Ek mag verkeerd wees in die verband en ek hoop werklik so, maar my bronne dui aan dat daar tans 'n bitter skraal kans is dat so iets gaan gebeur weens verskeie redes, die grootste hiervan die gebrek aan fondse asook die politieke klimaat.

Laastens diengene wat nog nie die voorreg gehad het om met 'n Suid Afrikaanse satelliet kontak te maak nie, dit is 'n asemrowende ervaring / gebeurtenis.  Die afwagting, voorbereiding, landsering, aanskakeling en eerste "lewe" van 'n Suid Afrikaans vervaardigede satelliet is iets wat geen radio amateur,  elektroniese ingeneur of student mag misloop nie. Die eerste kontak dmv amateur radio met die satelliet is in my opinie 'n lewens veranderde gebeurtenis.  Kom ons hoop en vertrou dat diengene wat nog nooit met 'n Suid Afrikaanse vervaardigde satelliet kontak gemaak het nie, dit eendag nog sal beleef.   

Hier volg 'n kort uiteensetting tov Sunsat se kommuniksie besonderhede:

SUNSAT se kommunikasie gebruik die stoor-en-stuur-konsep en die PACSAT-protokol suite om die dienste te verskaf vir amateur radio kommunikasie (VHF, UHF, L- en S-bande), data-afskakel-VHF (145.825 MHz), UHF (436.25 & 436.30 MHz) ), S-band (1260 of 2400 MHz), data-insameling (VHF, UHF), en ruimtetuigbeheer. Verskillende frekwensies word soms vir verskillende dienste benodig. Die kragversterkers het 5 W uitset tov VHF en S-band en 10 W uitset tov UHF. Die S-band afskakel laat 'n data snelheid van 40 Mbit/s toe in QPSK-modulasie. 'n 64 MB RAM-skyf word vir beeldberging gebruik.

Benewens tweerigting kommunikasie, het Sunsat 'n papegaai herhaler aan boord gehad wat kort sarsies spraak opgeneem en dit dan herhaal het. Onderwysers het dit veral nuttig gevind in taal onderrig aangesien leerders hul eie toespraak kon hoor met die bykomende opgewondenheid dat dit uit die ruimte kom.  Die papegaai herhaler was die "brein-kind" van Henry Chamberlain ZS1AAC wat ook nou betrokke was by die SunSat satelliet.

( QSL Kaart Sunsat - Universiteit van Stellenbosch)

Wie het die eerste amateur radio kontak bewerkstellig dmv die Sunsat satelliet?

Garth Milne ZR1AFH in Stellenbosch en Hans van de Groenendaal ZS5AKV in Hillcrest (KwaZulu-Natal) het op Sondag 14 Maart 1999 geskiedenis gemaak toe hulle die eerste stemkontak ooit gemaak het met SUNSAT. Die stemkwaliteit was uitstekend en seine sterk selfs wanneer die satelliet die horison genader het.  Dit was lonend dat die eerste toets-stemkontak wat gemaak is deur middel van amateur radio geskied het.  Radio amateurs was van die begin van die projek 10 jaar gelede betrokke, het SA AMSAT se president Hans van de Groenendaal ZS5AKV gesê.

Die laaste kontak deur grondbeheer met SUNSAT was op 19 Januarie 2001 en op 1 Februarie 2001 is die einde van SUNSAT se funksionele lewe in 'n wentelbaan aangekondig. Die satelliet het vir byna 2 jaar in 'n wentelbaan gefunksioneer.

Daar word voorspel dat dit weer die atmosfeer sal binnedring na ongeveer 80 jaar leeftyd vanaf lansering.

Die onderstaande klank insetsel is met die vergunning van "Sterre en Planete" wat aangebied word deur Hennie Maas op Radio Sonder Grense. Luister gerus elke Sondagaand om 19h30 na Sterre en Planete!!

Indien die klank insetsel nie will speel nie laai dit gerus HIER af om daarna te luister.