Sunday 27 May 2018

CTARC Photos of May 2018 Meeting - 28 May '18

Here are the photos of Deon ZR1DE's talk at the CTARC on 26 May 2018. We will try and get Deon's Powerpoint slides later, which are far better than my photos of slides projected on a wall!
The text report-back is [here].

A great turnout for the meeting, representing all ages in our growing club

Rob ZS1SA opens the meeting and gives feedback on the
committee meeting

Deon ZR1DE commences his oresentation and mentions
the AMSAT SA Space Symposium

Polar and Equatorial orbits

Ground tracks help predict when and where the satellite is visible

The deployment pod that launches sets of CubeSats

The primary satellite that carries the launching pod/s

SDR Dongles have revolutionised inexpensive monitoring,
of HF through to UHF frequencies

Satellite data summarised in a graph

Data analysed by Fast Fourier Transform

Data from a single orbit. This graph shows current generated
by the satellite's photovoltaic cells

Cumulative data summarised from 4 years' worth of orbital data

Non-sun synchronous orbits affect the data collected

Deon responded to numerous questions from the audience

Ian ZS1SX examines a CubeSat frame at first hand. Note the deployable
antennas poking out the sides

After the meeting, Chris ZS1CDG shows off the foxhunting fox
he's constructing

Ever helpful, Peter ZS1PGC (centre) tests a VHF/UHF antenna for Paul ZS1S (right) with his antenna analyser.
Raising the yagi off the ground later delivered better readings.

CTARC Report-back on May 2018 Meeting - 28 May '18

Here is the report on the May 2018 meeting of the Cape Town Amateur Radio Centre.

The meeting was held, as is usually the case, on the fourth Saturday of the month at 14h00 B. This was Saturday 26 May 2018 and the meeting at our Rondebosch clubhouse was very well attended. Word had spread about the speaker and topic! Our chairman, Rob ZS1SA called the meeting to order promptly and gave us some feedback on the recent CTARC committee meeting held the previous Monday. Various matters come to hand:
  • The Morningstar remote station is up and running and in regular use now, and Rob reminded us of the annual access fee payable by users, which is needed to cover the rental on the property. More on the Morningstar remote station here;
  • Then, there are still some CTARC name badges which have been ordered, paid for and made, but as yet remain uncollected;
  • The Committee (specifically Peter ZS1PGC) has set up a PA system in the clubhouse to assist people sitting in the back rows of the meetings to hear the speakers;
  • We have appointed an honorary auditor (in the person of Danny ZS1BL) to keep an objective eye on financial matters now that our exisiting auditor (Barry ZS1FJ) has joined the committee, thereby avoiding a conflict of interests;
  • We are preparing for the CTARC's AGM which takes place at the July meeting;
  • As our "Lighthouse Weekend" yagi beam antenna (the Force 12 C3) is now mounted atop the club's main mast (since the July storms of 2017), we need to make a plan for a proper HF beam antenna for the Lighthouse Weekend event at Green Point lighthouse, which takes place this forthcoming August;
  • The forthcoming meetings for June, July and August are coming up. Follow the links for details;
  • A certain radio amateur in our club is being recommended for an award and Paul ZS1S needs the signatures of a number of club members, who are also SARL members, to qualify this motion to the SARL council;
  • Tony ZS1TK put out a request for more volunteers to assist with reading our Sunday morning bulletins.
Admin matters concluded, Rob introduced Deon / ZR1DE, the main speaker for the afternoon. Deon needs little introduction, as he is very well known in our community for his enthusiastic interest in Satellites, his active involvement in the Kletskous CubeSat programme at the Cape Peninsula University of Technology and in the worthy AmsatSA organisation.

Deon's well-illustrated presentation was about CubeSats in general, and the FunCube in particular. He launched his talk with a description of how satellites are sent into space by rocket, and how the item, once launched, can remain in orbit with at least a minimum necessary velocity to stay aloft. He showed a map of the main (mostly military) launching sites across the globe, and how South Africa is in a unique position to be the first to spot satellites launched westwards from the US east coast.

We were then introduced to the concepts of Equatorial and Polar orbits, and the "footprint" of satellites as they pass over a stationary observer/radio ham station below, with an available window of about 15 minutes (if the observer below is lucky enough to have a good pass). We saw a slide of the Vandenburg USAF Base from which many satellites are launched from the USA.

What isn't generally known is that CubeSats were borne out of the need to provide ballast on certain satellites for ballistic purposes, until someone had the great idea of using deployable mini-satellites instead of cubes of concrete!

Deon then introduced us to the FunCube satellite, which started off initially as a university project to provide outreach to schools in the UK to generate interest in Space technology. This 100mm square cube has sensors on its corner columns to measure various parameters such as temperature and sunlight, which is then sent by telemetry back Earthside, where an enthusiastic following of people track the satellite and turn its raw data into usable spreadsheet format.

The FunCube has a small computer to run its functions, but no hard drive would survive the launch (or cosmic radiation), so it rather loads up the BIOS and operating system via a miniscule SD card. This means if the system gets corrupted, it can be re-uploaded again.

Similarly, the rigours of launching mean no antenna could survive, so these have to be extended outwards from the CubeSat only once it has been deployed outwards from the spring-loaded launching pod. Up to as many as 12 CubeSats have been deployed from the mother satellite in one go, but typically one, two or three CubeSats are deployed per pod.

The FunCube has antennae for the 2 metres and 70 centimetre ham bands. These are thin (but sufficiently stiff) metal tapes that are unwound to the correct length from the sides of the satellite.

Deon then gave us more insights into the data that the FunCube provides. Initially starting off as analogue measurements taken by the FunCube's sensors, these are then digitised and transmitted from the satellite back to Earth. (An ancilliary project, the FunCube Dongle SDR, has been developed to enable the teams to receive the data directly from the satellite.) This is where the project really comes alive, because the data can be tracked, decoded and analysed to provide functional information about what the satellite is sensing. It gets more involved when trends are analysed over time - daily, weekly and monthly. Deon showed us some fascinating graphs assembled over 16 weeks that show specific trends in temperatures and other parameters measured by the FunCube.

And, of course, there is the transponder, which enables radio hams to contact each other - transcontinentally at times - while the satellite is overhead. You do not need a kilowatt to work FunCube (if you try that level of QRO, the poor widget will switch itself off to prevent its receiver getting burned out!). 20 watts and a dipole antenna (or Yagi) are usually quite sufficient.

Deon concluded by answering questions from the audience, and received a good round of applause for his very interesting talk.

Thereafter we all had the chance to catch up and chat, and to buy and sell things in the monthly Swop Shop. Thanks so much to Deon for his talk, and to everyone else for attending.

Photos are [here].

Details of next month's meeting (June 2018) are [here].

Thursday 24 May 2018

CTARC Forthcoming May Meeting - 26 May '18

Deon Coetzee ZR1DE with prototype space frame – Image Credit: SA AMSAT
Deon Coetzee / ZR1DE
with prototype space frame.
Image Credit SA AMSAT
The monthly CTARC meeting for May 2018 will be held at the clubhouse on Saturday 26 May 2018, starting at 14h00.

The speaker for this meeting will be Deon Coetzee / ZR1DE, with a talk on the SA AMSAT radio amateur satellite projects and the FunCube SDR.

Deon's enthusiastic involvement in this field over the years is well known and he is an established authority on the subject, and it promises to be a most interesting talk indeed.

Please note that this topic / speaker replaces previous notifications for the 26 May 2018 meeting. We do apologise for any confusion that might have been caused.

Details of our forthcoming meetings are usually announced on our Sunday morning CTARC bulletins on the 145.750 MHz repeater, in our newsletter "Ragchew" and on this blogspot.

Note: This meeting has now taken place. The report-back is [here].

CTARC Request for Assistance - 24 May '18

There is an urgent request for assistance from Klaus / ZS1QO for fellow radio hams and club members to help him finish dismantling his radio station in Rugby in Cape Town. Klaus and his family are set to depart the QTH quite soon, and his state of health prevents him from doing this big job on his own. While his masts are now dismantled and antennas are down, there is still work to be done.

He also still has quite a large selection of amateur radio rigs, antennas and accessories for sale too. Here is an extracted list of items that appeared recently in the Highway Amateur Radio Club swops page:
Update offer to sale:
  • Military Handset, new, for B25 and similar MIL Radios complete with MIL-Plug,
  • Synthesized Digital Generator FARNELL DSG-1 0,0001 Hz to 99,99 kHz - very rare, among else used for CTCSS calibration-, 
  • Audio Signal Generator HP204C, 
  • Calculating Frequency Counter 0.1 Hz to 2.5 GHz, made in Germany by AUERSBERG, 
  • Oscilloscope Siglent SDS 1102CML dual-beam storage 100 MHz, 
  • D-Link Wireless N150 ADSL2plus Modem Router, 
  • Tono 5000E CW / RTTY / AMTOR Encoder/Decoder including keyboard, 
  • 12-Pin power cables for Yaesu FT-101 Series and Kenwood, 
  • VHF Mobile Antennas with magnetic base,
  • Good Quality Coax Cable RG58 - 50m Reel, 
  • DC twin-core power cable red/black, 
  • Special Radio Power Plugs, 
  • Military Plugs - many different types, 
  • Commercial Radio Direction Finder 100 MHz to 180 MHz, 
  • SWR Meter 1.8 MHz to 570 MHz, ranges 5W 20W 200W, 
  • HF Transceiver ICOM IC-751A (including non-volatile EPROM). 
  • Transformer Power Supply 220 V / 13.8 V 30 A cont. 32 A peak, 
  • Transformer Power Supply 220 V / 13.6 V 3.5 A, 
  • Automatic Antenna Tuner Daiwa CN2002 with cross needle meter,
    Range 20 W / 200 W / 2000 W PEP, 12 V operated,
  • Portable 2m Transceiver TR-2300 with built-in CTCSS board and ext. Amplifier VB-2300, 
  • 4 x High Quality German Loudspeakers - 4 Ohms 25W, 
  • Kenwood Hand Microphone MC35S 50 kiloOhm with 4-pin connector, 
  • Other dynamic microphones with 4-pin and 8-pin connectors, 
  • VHF 2m Mobile Antennas with magnetic base, 
  • Big box of coax plugs and sockets - PL259, N-Type, Barrels, BNC, adapters PL/BNC, N/PL, N/BNC, PL/SMA and more.
Kind regards
Klaus ZS1QO
Klaus requests you contact him by direct mobile phone call, please NOT by WhatsUp nor by SMS. You can do so on: [ zero 8  three = 6 too six = six  9  six  4 ].
He may also be e-mailed at comlab at global dot co dot za

Monday 7 May 2018

CTARC Project Loon - 6 May '18

This is an experimental research and development project by formerly Google X. This project is to provide internet access to rural and remote areas. This project uses high-altitude balloons placed in the stratosphere at about 18 Km above sea level.

Two of these balloons have been spotted on an app called "FlightRadar24. (which please Google).

One is about to fly over Cape town in the next few day. As of writing (6 May 2018) at 11h00, balloon Registration N189LB is at an altitude of 57,300 Ft in position Latitude -33.475 and Longitude 13.5493. The track is 104 degrees slightly south of due east. If it continues on it's current track it will pass very close to Cape Town.

It might be possible to bounce VHF or UHF signals off the Mylar balloon material.

There is another balloon which is presently over southern Angola. It's registration is N183LB.

Check out Project Loon on Google and [here and here], and also FlightRadar24 [here].

Hope this is of interest.


Hans ZS1HA

CTARC Ragchew - May 2018

The May 2018 edition of the Cape Town Amateur Radio Centre's bi-monthly newsletter "Ragchew" is now published.
Grateful thanks once again to our editor, Anne, for all her excellent work in putting together this month's edition, and to all those who contributed articles.
Remember please, Anne is always on the look-out for articles to publish in Ragchew!

Download the PDF file [here];

Ragchew is also on our Newsletters Page

Friday 4 May 2018

CTARC More Photos of Morningstar Station - May '18

Here are some more photos of the Morningstar Remote Control Station.
Grateful thanks to Dennis / ZS1AU for providing these.

The station's location, sheltered by an aircraft hangar.

The station's mast, Optibeam HF antenna, 6m beam above that,
2x microwave dishes and 2m discone antenna

Fred / ZS1FZ, who concieved and built the Morningstar station

In te background is the Ham Spirit Trophy, which Fred won this year