WHEN ALL FAILS AMATEUR RADIO SUCCEEDS
Something has gone terribly wrong. Normal ways of doing things are not working. The fastest way to turn an emergency into a full disaster is to lose communications.
Radio Amateurs understand emergencies. For over 70 years they have provided emergency communications for organisations. When normal ways of communication fail or get overloaded Radio Amateurs will be there.
HAMNET, the National Emergency Communications division of the South African Radio League (SARL), provides communications for emergencies and can mobilise experienced communicators who with their own radio equipment will back up official channels or take over when all else fails.
The SARL represents all Radio Amateurs in South Africa at all levels of Government and through the IARU at the International Telecommunications Union. Radio Amateurs or "Hams" use two-way radio communication to make contact with other radio amateurs all over the world. They are even able to use satellites and on occasion speak with astronauts. Radio Hams can do this from home or while mobile in cars, boats or on foot.
Radio Hams have a full range of communication modes at their disposal. These include plain voice, Morse code, numerous digital computer modes and even graphical modes like television. A licensed radio amateur is able to join in experiments using all these modes.
HAMNET CALL-SIGNS, MEETINGS AND BULLETIN SCHEDULES
SUNDAYS - during the AMATEUR RADIO TODAY transmission, starting at 10h00 South African Standard Time (SAST), on HF and on many VHF and UHF repeaters around the country. (Current bulletin posted below)
Western Cape ZS1DZ or ZS1DCC
On the 1st Wednesday evening of the month, HAMNET's Western Cape monthly meeting is held at 19h30 SAST at Tygerberg Hospital's Provincial Emergency Management Centre.
The radio bulletin is transmitted at 19h30 SAST on a Wednesday evening, on the local 145.700MHz repeater, with relays on to 1845 or 3760, and 7110kHz LSB, 144.300MHz USB, and Echolink, via ZS1DCC-R, on the 2nd and consecutive Wednesdays of each month.
Eastern Cape ZS2PE or ZS2BRC
There is a weekly net on 52.950MHz at 20h00 SAST on a Wednesday evening, and local HAMNET news is included in the PEARS bulletin on Sunday morning at 08h45 SAST on the 145.700Mhz repeater, with a relay on to 7098kHz LSB.
Northern Cape ZS3NC
Free State ZS4DCC
KwaZulu Natal ZS5DCC or ZS84SIG
Quarterly meetings are held on the 2nd Saturday afternoon of the month, at 12h30 for 13h00 SAST, either at Ethekwini Disaster Managment Centre or the 84th Signals Unit in Durban. The next 2 dates are 10/9 and 10/12.
On Sunday mornings at 07h00 SAST, on 145.625MHz, there is a bulletin, also relayed on to 3760 and 7110kHz.
There is a formal radio bulletin at 19h30 SAST once a month on a Wednesday evening,on the 145.625MHz Highway repeater, and informal nets at the same time, and on the same frequency, every other Wednesday evening.
Gauteng South ZS6
Monthly meetings are held on the first Thursday of the month at 19h00 SAST at the East Rand Branch clubhouse. On all other Thursday evenings, a social gathering is held at the same venue to chat or maintain equipment.
Gauteng North ZS6PTA
Northern Western Province ZS6
HAMNET REPORT 17 JULY 2016
National Director Paul van Spronsen ZS1V has announced the new-look HAMNET website, accessible at hamnet.co.za. A basic description of emergency communications is provided on the home page, the weekly news bulletin you are listening to now is printed on the news page, a page for news from all the divisions is next, to be populated with news by a designated reporter from each division, and then a page for operations reports and another for event reports. Calls for volunteers to help with activities may be placed here too. The website is open and available for all to read, and we hope you will learn to access it regularly to keep up with HAMNET news in South Africa.
A very clear and concise discussion of the types of solar panels available and their uses has been provided by Chris Warren, who runs a blog called "Off Grid Ham". He notes that hams are not well versed with the attributes of the 3 types of solar panels available: Monocrystalline, Polycrystalline, and Thin Film.
Monocrystalline panels use high quality silicon cut into individual cells, attached to each other and seen as small separate patches on the panel with electrical connections. Polycrystalline panels have molten silicon poured into a mould. They have thin metallic wires dividing the panel into cells, but are in actual fact one single large patch. Thin film panels have a silicon photo-reactive semiconductor applied to a substrate, usually thick plastic. These latter are flexible and may be rolled up.
Monocrystalline panels are more efficient than polycrystalline panels, producing 4% more wattage per square metre, and have a longer service life and a greater tolerance for extreme temperatures, but the differences do not justify the extra price per square metre of panel, not in the kind of sizes used by radio amateurs. Both systems' service life can run over two decades, more that you might ever need.
Thin film panels are inexpensive when used at low power levels, and are freely available. Their flexibility also carries an advantage if you are doing a Summit On The Air activation and want to carry them up a mountain! They are usually below 10% efficient, compared to about 13% for Polycrystalline and about 19% for Monocrystalline panels.
On balance, you will get the most wattage for your sized total panel layout per Rand spent on a polycrystalline panel system, their slightly lesser performance compared to monocrystalline panels more than offset by the reduced cost. And if you're thinking of spending money rigging up a sun-following panel system, let me tell you that it would be cheaper to buy another polycrystalline panel or two and gather more sunlight that way, than to have your smaller layout follow the Sun
Thanks to Chris Warren for the concise summary.
This week's ARRL newsletter carries a mention of a training Webinar set for 24th July, hosted by Ward Silver N0AX, entitled "Contesting as Training for Public Service".
"Think of contests as a ham radio fitness centre," Silver said. "Public service teams are always looking for enjoyable activities to improve operator skills. Just as sports provide good physical exercise, contests are great at developing radio skills, and both are a lot of fun." Silver pointed out that contests originated as a way to hone traffic-handling skills and develop an effective station.
The ARRL's recent National Field Day is a good example of a huge experiment, by thousands of hams, working in groups mostly, working to test their radios, antenna systems, and off-grid power systems, with a view to establishing an understanding of the best way they can offer an emergency service in time of need. It is just unfortunate that this year's solar conditions are so poor that high numbers of QSO's were not possible.
Astronomy Magazine's weekly newsletter tells us that China's Five hundred metre Aperture Spherical Telescope, or FAST, has been completed 3 months ahead of schedule. The surface area of the radio dish is equivalent to that of 30 soccer fields, it cost $180 million to build, and took 5 years to complete.
FAST is tasked with many projects involving studying strange objects such as quasars, pulsars, and gravitational waves, as well as searching for extra-terrestrial life, all with the intention of understanding better the origin of the universe.
The previous biggest radio-telescope is the 305m Arecibo dish in Puerto Rico, which has been doing similar research for 40 years. From there the most powerful broadcast ever deliberately beamed into space was made in 1974. A megawatt transmitter's signal was concentrated into a beam, equivalent to a 20 trillion watt omnidirectional broadcast, but aimed at an area in the globular cluster M13 about 21000 light-years from us, and containing about 300 000 stars. The total broadcast took less than 3 minutes to send, and consisted of 1679 bits of information, sent by frequency shift keying, at the rate of 10 bits per second. An answer from the stars is not expected any time soon, so don't hold your breath.
The experiment was useful in getting us to think a bit about the difficulties of communicating across space, time, and presumably a wide culture gap!
This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.