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VK7AX > BCAST 17.12.22 09:03l 341 Lines 26258 Bytes #999 (0) @ WW
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VK7 Amateur Radio News 18Dec22
Text edition:
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VK7 AMATEUR RADIO NEWS BROADCAST
FOR SUNDAY 18th December 2022
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Seasons Greetings and welcome to the VK7 Amateur Radio News and this was first broadcast on Sunday the 18th December 2022. At the mike of VK7WI this week is Rick, VK7RI.
On Sunday this broadcast goes out on repeaters all over VK7 and on digital radio - DMR Talk Group 5 and D-Star Reflector 91C by Clayton VK7ZCR.
We go out on medium and high frequency courtesy of the following rebroadcast stations:
On 1.862 MHz by Graham, VK7GS,
On 3.670 MHz by Dale, VK7DG,
On 7.140 MHz by Peter, VK7TPE,
On 14.130 MHz by Ross, VK7ALH and
On 28.525 MHz by Garry, VK7JGD.
We also go out on UHF CB Channel 15 thanks to Mark VK7FMAC in the Hobart area.
You can hear this broadcast again on Tuesday night at 8:00pm on repeaters VK7RAA in Northern VK7 and VK7RAD in Southern VK7.
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Thursday Night SSTV Nets
Another quiet net night that saw the following participants VK7s – ZAB, ZBX, LEE, ZSB, BAM, PD and PAK all sharing fourteen photos. There were varies subjects like:
Lights from vehicle traffic but no traffic lights tonight
TV comedy from “The IT Crowd”
Scenes of storm clouds with a lightning strike and the Light House on Tasman Island as seen from “The Three Capes Track”
A friendly cat soaking up the heat from a laptop computer and a not so friendly looking Komodo Dragon
Day and then night time microwave link setups
Some of the radio sites on top of rocky Mt. Arthur
An International Lighthouse Weekend activation
Ending with a very happy character
Remember Ken VK7KRJs and Steve VK7OOs fully automatic 24/7 monitoring site that allows anyone who has sent an SSTV picture the ability to check them on their pages almost immediately, any time, both South and North Tasmania.
A reminder in Southern Tasmania, VK7RAF (146.650 -600kHz) can be used both locally and linked to VK7RJG by using different CTCSS tones. 123Hz for local Southern operation and 141.3Hz for linking RAF to VK7RJG (438.55 -7MHz).
We get underway from around 7:30pm.
https://vk7oo.tasme.com/vhfsstv
https://www.ntarc.net/blogs
https://sstv.vk7krj.com/scrolling%20web%20gallery.html
73 Andre VK7ZAB
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NEWS FROM THE NORTH
SOTA/WWFF PARKS GROUP
The Summits On The Air/World Wide Flora and Fauna parks group meets twice weekly – Mondays and Fridays 10.30AM till 12.00 at the Glebe Gardens Cafe, Henry Street, Launceston.
For more information contact Al on 0417 354 410.
73, Al, VK7AN
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Northern Tasmanian Amateur Radio Club Incorporated
www.ntarc.net
We will start this week with a round up on the end of year dinner. Well for summer it was certainly a cooler night than was expected and unfortunately there were quite a few unable to attend due to sickness and the inevitable clashing of engagements at this end of the year. However a good number of members rocked up to the Mowbray Hotel in Launceston on Tuesday evening for the annual NTARC Christmas Dinner. It was great to see at least half a dozen faces we havent seen for quite a while, mainly due to distance or health problems. With the re-unions came much laughter and cheerful banter going on as we all discussed the menu before ordering. There was an excellent selection, something for everyone. Orders were taken and service was fast. The food was magnificent, everyone seemed happy. There were no disappointments this year as there were adequate supplies of Sticky Date Puddings and Banana Splits to round off the evening. A great time was had by all. We all made our way home thoroughly satisfied.
The last Club Room Technical Night session for 2022 also saw a great roll up of attendees.
I mentioned before that it is summer, but thank you Stuart VK7FEAT, for stoking the fire up and removing the chill that we must all have been imagining.
Ross, VK7ALH came in with a couple more examples of what has been across his repair bench recently. Not radios this time but never the less very interesting.
The first was a UniMig CUT40 Inverter Air Plasma Cutter, basically the complete unit utilising the same mother board as shown and discussed at the last Tech Night, mainly because it incorporated a “Spark Gap”. The second item was a Lincoln Powercraft 185, a small single phase inverter welder that is capable of 185 Amps and weighs in at just 4.2 kilograms and is physically very small.
We received a very interesting run down on construction, operational differences and general design. But as both these units have been deemed as “Commercially uneconomical to be repaired” and were replaced under warranty they were receiving special attention as to salvageable electronic components. Everything from high capacity and voltage capacitors, switching transistors, HF usable Ferrite cores and physical cases. It would be such a shame to send them to recycle.
Lionel VK7ZLB, brought along a quite different co-axial cable assembly for a fixed frequency transmitter installation. It provided “stub” blocking filters for the 3rd, 5th and 7th harmonics. Rather than the usual off the shelf “T” connectors Lionel used machined sections of copper to tee of the stubs from the main passing through RG213 co-axial cable.
All stub calculations were based on a specific fundamental frequency in the 104MHz area.
To compliment the filter he had the accompanying 50 ohm four port power splitter that he also made. This provided equal power feeds on all ports, allowing for the connection of four mixed polarisation antennas. This splitter was constructed from solid brass stock about three quarters of a metre long and would have required some pretty accurate end boring to hollow it out. The incoming feed was an “N” type connector with four BNC sockets at the other end for output. Once again a high standard of construction.
Lionel also brought an assortment of 50 Ohm home constructed low power dummy loads. He instructed us in ways of maximising the usable frequency response from appropriate construction techniques. They consisted of PL259, “N”type and BNC plugs and could offer far superior bandwidth performance compared to a lot of E-bay very suspect “cost effective” alternatives.
As would be expected all discussions were interspersed with copious amounts of coffee, tea and eating. Many thanks to members that furnished the night with sandwiches, cakes and even doughnuts to make things more festive. An excellent end to a technical year. Thank you to all who have contributed to the very eclectic selection of items that have passed through the club rooms for show and tell throughout the year, they certainly have acted as a catalyst for many discussions.
From everyone at our technical sessions both club rooms and on air throughout 2022, we wish all a very happy and safe Christmas and we are looking forward to more Amateur Radio fun in 2023.
Dont forget there is still one more TestNet and TechNet session with Nic VK7WW, at the helm next Wednesday night.
While talking of Nic and his CW course it is nice to note that Peter VK7KPC, has received a certificate in recognition of his participation in the Don Edwards Memorial Slow Morse Contest for 2022. This contest is run by St. George Amateur Radio Society Inc. in New South Wales and is generally held in May each year, well done for your participation.
Remember all equipment photos are available on the NTARC web site under “Blogs” for this broadcast date.
Friday coffee morning, saw Ros as usual arriving early to set the room up and possibly vacuuming the floor, as we have been known to forget vacuuming before leaving on a Wednesday technical night, sorry Ros. We really do appreciate your dedication for what realistically ends up being nearly every Friday in the year! When you consider you also bake a cake for each coffee morning thats an awful lot of work. Thank you Ros. We had a very large roll up for our final coffee morning, with much merriment, chatter, coffee and the obligatory food consumption. A happy ending to the year.
It looks like Santa must have come a week early to some of us that are in his “Good Book”. Bill VK7MX, showed off his brand new small, as in hand held, spectrum analyser. This is the latest incarnation of the 2.8 inch screen version and now sports a very crisp 4 inch colour display screen. This is a considerably useable size increase over the older model and much easier on our aging eyes.
The unit is capable of functioning well over 5GHz, both in spectrum analyser and signal generator modes. One wonders if it will be wrapped up and left under the tree until Christmas day?
With that now behind us, this is a gentle reminder that the clubrooms are now closed for the Christmas/New Year recess but will re-open on Friday the 13th of January 2023.
Club Membership
Its that time of the year again - All club members should have received an e-mail with instructions on renewing their membership for 2023 by now. If you havent received the e-mail please e-mail the secretary with your updated contact details. For those that we dont have an e-mail address for, you should have received a letter and renewal form send via snail mail by now.
P.S. A big shout out to Martin VK7JAH, hope you are soon out of hospital and on the mend.
UPCOMING EVENTS
The last TestNet and TechNet for this year will be - Wednesday 21st December. TestNet/CW course on 3.580MHz from 7pm till 7.30pm….and a TechNet on 3.567MHz from 7.30pm till about 8.30pm. Your host for the evening will be Nic VK7WW. This is the last “formal” night, but who knows it might be worth a frequency check over the Christmas New Year break as amateurs have been known to just talk for the fun of it.
The last Friday Coffee Morning for this year has just passed us by. Will be resuming on Friday the 13th of January at the NTARC Club rooms.
The last Club Technical night for this year has also passed us by. It will be resuming on Wednesday the 18th of January at the NTARC Club rooms and yes it will be 2023 by then!
FINALLY - A reminder to all members that if you have any items of news you would like added to our weekly roundup, no matter how trivial, then please email them to the Secretary at the following address news(at)ntarc.net all items to be received no later than 5pm on the Friday prior to the Broadcast.
Thats all folks,
73 from Stefan, VK7ZSB, Secretary NTARC.
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NEWS FROM THE SOUTH
Radio and Electronics Association of Southern Tasmania
https://www.reast.asn.au/
https://www.facebook.com/reasttas/
https://www.youtube.com/reasthobart/
DATV Experimenter's Night
https://fb.me/e/2JoFedbKt
Last week our DATV Experimenters Night started with Justin VK7TW showing a RaspberryPi equipped with a Power Over Ethernet hat. This board connects to the 40 pin GPIO connector and the POE connector on the Model 3B and 4B RaspPi single board computers.
Justin also showed the power injector to supply the 48V along the Ethernet cable to the hat that converts the 48V to the 5V 3A required by the RaspPi.
Justin then reminded viewers of the annual Geminid meteor storm that that night.
https://www.abc.net.au/news/science/2022-12-13/geminid-meteor-shower-2022-australia-sky-guide/101745404
We then went into a presentation on the WIA Response to the ACMA Class Licence and Higher Power Consultation.
We covered the Class Licence Changes and next week we cover the Higher Power Suggestions.
We finished up by reviewing the contents of the latest AR Magazine.
This coming Wednesday night as well as covering the Higher Power WIA submission there will be some interesting morse keys and much more.
We intend to have DATV Experimenters nights throughout the Christmas and New Year break so, why not come up and see what we get up to.
We stream the nights on the REAST YouTube channel.
https://www.reast.asn.au/news-events/live-stream/
https://www.reast.asn.au/special-interest-groups/amateur-tv/
We go out on RF - DVB-T 7MHz Standard Definition on 445.5MHz. So, if you have a TV, Set-top box or USB DTV Dongle that you can tune and scan 445.5MHz and you can see the Queens Domain, then you have a good chance of receiving the DATV Experimenter's Night Signal. Look out for VK7OTC. We also stream the nights on the REAST YouTube channel.
https://www.reast.asn.au/news-events/live-stream/
https://www.reast.asn.au/special-interest-groups/amateur-tv/
https://www.youtube.com/c/ReastHobart/
73, Justin, VK7TW
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Radio Astronomy News
Radio quiet to enable big science
For years, a huge adventure in science has been quietly taking place in Western Australia. Now a new stage is starting with the construction of an international telescope. This is the story of the site, the telescopes, and the radio quiet measures to protect them.
What is radio astronomy?
Everyone knows stars emit light. Starlight is produced by physical processes, and even at the speed of light, it can take millions or billions of years to reach Earth. Looking at the stars is literally looking back in time.
Its less well-known that stars give off radio energy, as do other objects in space, such as dust or gas clouds. These radio signals arent coded with information like mobile phones or FM radio, so they appear as noise or static. Measuring the frequency and power of this radio noise provides information about the chemistry of celestial objects and their location, size and speed relative to Earth. This measurement is radio astronomy. It complements optical astronomy (and at other wavelengths) to study the structure of the universe, just as X-rays, CT scans and MRI complement each other in a medical assessment.
Radio energy from stars is very faint its produced by atomic and molecular transitions which are individually extraordinarily small, multiplied by the large number of atoms in a star or dust cloud. These signals travel for billions of billions of kilometres, so the energy measured on Earth is many orders of magnitude less than human-made radio signals. Radio astronomy observations therefore require large receiving antennas (or a distributed array), specialised sensitive receivers and long integration times.
The radio frequencies emitted by cosmic objects are fixed by their chemical and/or physical components. For example, neutral hydrogen has a rest frequency of 1420.406 MHz. Due to the expansion of the universe, cosmic objects are not only moving away from Earth, but are moving faster the further away they are. The Doppler shift means the observed frequency is much lower than the rest frequency. Consequently, radio telescopes need to observe over frequency bands allocated to radiocommunication services.
The next generation
Ideally, radio telescopes are built in areas with minimal interference from other radio sources. Those designed in the mid-20th century, such as CSIROs Parkes radio telescope Murriyang (The Dish) in NSW or Jodrell Bank in Manchester, UK, were built when radio communication was far less ubiquitous. Over time the growth of radio communications, particularly mobile radio devices, has created significant radio frequency interference (RFI) at such sites.
In 1993, the International Union of Radio Science (URSI) established a working group to plan a next-generation radio telescope with 100 times the spatial resolution and 100 times the sensitivity of existing instruments. It was estimated that this would allow observations to the edge of the observable universe and therefore to the first few moments after the Big Bang. The original concept was to have an effective collecting area of about 1 km2 and observe from 100 MHz to 25.25 GHz, with different technologies to cover the low, middle and higher frequency ranges.
Among the many considerations about where to build this telescope, a site with significant protection from radio frequency interference was a key requirement. Five countries Argentina, Australia, China, South Africa and the USA bid in 2003–04 to host the project. Following evaluation and preliminary RFI measurements, Australia and South Africa were shortlisted. After further studies and measurements, it was decided in 2014 to split the telescope between the two countries. The low-frequency component, SKA-Low, observing at 50–350 MHz with dipole antennas, will be built in Australia. The mid-frequency component, SKA-Mid, covering 350 MHz to 15.4 GHz with parabolic dishes, will be constructed in South Africa. This is now the SKA project, managed by the SKA Observatory.
The Australian site
Australia proposed a site on Wajarri Country in Murchison Shire, Western Australia, which has no gazetted towns, is approximately the size of the Netherlands and has a population of around 100 people. The region includes the Pia Wajarri Aboriginal community, large pastoral stations and mining. As a result of the low population density, there is little radio frequency interference from terrestrial systems. The nearest cell tower and broadcasting site are at Cue, about 150 km away.
CSIRO, Australias national science agency, acquired the lease for Boolardy Station, which has an area of 3467 km2, to establish an observatory. Precursor telescopes were constructed to test technology solutions, to demonstrate the benefit of the radio quiet protection, and as world-class instruments in their own right. The observatory currently hosts the Murchison Widefield Array (MWA), constructed by Curtin University and international partners and completed in 2013; CSIROs ASKAP radio telescope, completed in 2014; and the ‘Experiment to Detect the Global EoR Signature (EDGES), which started observations in 2015 and is operated by Arizona State University and MIT.
In November 2022, the Murchison observatory was given a dual Wajarri name Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory incorporating a Wajarri phrase meaning ‘sharing the sky and stars.
After years of planning and design work, the commencement of construction for SKA-Low was announced on 5 December 2022; construction is expected to take eight years. SKA-Low will consist of more than 131,000 dipoles deployed in 512 stations, with a dense central core and three spiral arms, with a diameter of about 80 km.
Early in the planning stages, CSIRO approached the Australian Communications and Media Authority (ACMA) to seek RFI protection. The ACMA implemented an embargo in 2005 and a policy document, RALI MS 32, in 2007 which defined the Australia Radio Quiet Zone Western Australia (ARQZWA), updated in 2014 with minor technical changes. Key points of this policy were formalised in legislation through a Radio Frequency Band Plan in 2011.
RALI MS 32 stipulates that within 70 km of the centre of the ARQZWA, the ACMA is unlikely to issue any new apparatus licences in the frequency range 70 MHz to 25.25 GHz. Concentric coordination zones start at 70 km and vary in size depending on frequency, with the largest zone having an outer radius of 260 km for the frequency range 70 to 230 MHz, and smaller radii as the frequency increases. Within these zones, applicants for new apparatus licences must consult with CSIRO to show that the RFI from the proposed equipment will meet defined thresholds. Similar requirements apply to transmitters deployed under spectrum licences. Various class licences state that the user must not operate transmitters within the 70 km zone if they interfere with radio astronomy observations.
To minimise interference from incidental emissions, the Western Australian Minister for Mines and Petroleum created ‘Section 19 zones under the Mining Act (WA) where new mining tenements would not be granted. The WA Department of Mines and Petroleum (now DMIRS) implemented a Radio Telescope Mineral Resource Management Area where mining companies must work with the observatory to ensure that their activities are compatible with radio astronomy.
The Murchison Shire Planning Scheme includes requirements that new developments are evaluated for radio interference potential. And the telescope equipment itself is subject to strict requirements and shielding to avoid causing local interference from incidental emissions.
This unprecedented level of RFI control was a significant factor in Australias successful bid to host SKA-Low. It has already led to world-class astronomy results in frequency bands that cannot be used elsewhere in the world, particularly in 700–1000 MHz.
Nerida OLoughlin, Chair and Agency Head of the ACMA, has said, “As Australias spectrum planner, we are proud that our partnership with CSIRO and industry has created the conditions to support the radio astronomy successes at the Murchison observatory.”
Implications of the Radio Quiet Zone
CSIRO seeks to minimise the impact of the ARQZWA on residents and industry while still providing protection for radio astronomy. It must be emphasised that the telescopes are passive receivers and cannot cause interference to other radiocommunication systems.
It is understood that radio communications are essential to safety in such a remote area, and none of the radio quiet measures restrict use in a genuine emergency. While the use of satellite phones is discouraged under class licence conditions, none of the measures affect the coverage of the region by systems like Iridium, Globalstar, Thuraya or Inmarsat. Starlink has chosen not to provide coverage in the 70 km Inner RQZ to avoid having its subscribers create interference to the telescopes, but this limitation is currently being re-evaluated. Some mining activities may be restricted or may need to find alternative technologies, and CSIRO has worked constructively with several companies to find solutions. Similarly, some remote monitoring systems for pastoral stations cannot be used, but CSIRO is available to work on alternatives.
In summary, CSIRO is available to work with the radiocommunications industry and local people to facilitate essential communications while preserving the radio quiet that underpins future science.
https://www.criticalcomms.com.au/content/industry/article/radio-quiet-to-enable-big-science-300457865
Written by Carol Wilson from the CSIRO and sourced to the Radio Comms Web E-zine.
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Regular VK7 gatherings and events over the coming months:
Regular gatherings:
Sewing Circle Net – Daily on 3.640 MHz commences at 6:00pm AEDST.
Statewide SSTV Net - held every Thursday night via the North/South Link on VK7RAF/VK7RJG from 7:30pm. In the North and North West - VK7RJG on 438.55 -7MHz and in the South - VK7RAF (146.650 -600kHz) CTCSS tone 141.3Hz to link RAF North-South.
State-wide – MICROWAVE QSO Party – following the Sunday broadcast call-back on 1296.15 MHz FM. One group in the greater Hobart area and another in the greater Launceston area.
Then North-south digital contacts on 1296.2MHz using Q65-60B.
Stations in the Launceston area transmitting on the odd minute. Southern stations on the even minute.
SOTA/WWFF Group – Meeting Mondays and Fridays 10.30-12.00 midday at Glebe Gardens Cafe, Henry St, Launceston.
NTARC - Friday 13th January 2023 - Coffee Mornings resume at the NTARC Club rooms.
NTARC - Wednesday 18th January 2023 - Club Technical nights resume at the NTARC Club rooms.
Last NTARC TestNet and TechNet for 2022 – Wednesday 21st December - TestNet/CW course on 3.580MHz from 7pm till 7.30pm….and a TechNet on 3.567MHz from 7.30pm till about 8.30pm
NW VK7 – Wednesday from 8:00pm local – NW Tassie Amateur Repeater Group Net on VK7RMD
NW VK7 - Thursday commencing at 8:30pm local) - N.W. Tassie 2m DX Net 144.190 USB (upper sideband).
REAST – WAGS – Wednesday Afternoon Group meet in the Queens Domain Clubrooms from 12 noon.
REAST – DATV Experimenters Nights from 7:30pm live in the club rooms also on DVBT RF and YouTube Streaming
CCARC - 28 January 2023 - SSTV nights from 7:30pm using VK7RMD 2m repeater on Mt Duncan on the 4th Monday in the Month.
Events:
VK7 - 25 December 2022 - Perfect Propagation, an ICOM 7610 and a StepIIR at 30m all found under a rather large Christmas Tree!
VK7 - June 2023 - VK7 Amateur Radio Centenary
ALARA - November 2023 - ALARAMeet 2023 - Hobart Tasmania
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A reminder to those people rostered for next weeks Christmas Day broadcast:
Newsreader: VK7TW
Repeaters: REAST, NTARC and in the NW thanks to N W T A R C, West Coast Radio Group, Cradle Coast Radio Amateur Radio Club, VK7AX, and VK7DC
160m: VK7GS
80m: VK7TPE
40m: VK7ALH
20m: VK7JGD
10m: VK7DG
UHFCB15: VK7FMAC
DMR: Talk Group 5 and D-Star: Reflector 91C VK7ZCR
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You can hear this broadcast again on Tuesday night at 8:00pm on repeaters VK7RAA in Northern VK7 and VK7RAD in Southern VK7.
A huge thank you to all people and organisations that assisted with this broadcast.
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That concludes our VK7 Amateur Radio News Broadcast for this week.
You have been listening to or have just missed VK7WI. Next week the National WIA news can be heard at 0900 followed by the VK7 Amateur Radio News around 0930 hours.
Items for the broadcast can be emailed to vk7arnews(at)gmail.com
Further information about the broadcast can be found at the VK7 Amateur Radio News Groups.IO Group.
https://groups.io/g/vk7arnews
The deadline for items is 21:00 on Friday prior to the Sunday of the broadcast.
VK7WI is now closing but will reopen shortly for callbacks and relay reports. Callbacks will be taken on the frequency to which you are listening. Relay stations will use their own callsigns during the callback.
On behalf of the VK7 Amateur Radio News Team, 73, stay safe and Seasons Greetings from Rick, VK7RI.
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(Posted to the packet network courtesy Tony VK7AX)
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