Amateur Radio January 2015
Delivery expected from 29 January
 WIA Member Digital Edition Download
Editorial
Happy New Year
We are now well into the New Year. I trust that all is going well for you all. Already we have had significant fire events in Victoria and South Australia, with at least another two months of high risk potentially to come. The Victorian fires to date have seen only a small number of homes lost. Unfortunately, this is unlikely to be the case in South Australia with the large fire in the Adelaide Hills. As this Editorial is being prepared, we are seeing very heavy rainfalls predicted across the country as the tropical humid systems feed into low pressure complexes to the south. Whilst drenching rains would be welcome on the fire grounds with difficult terrain, elsewhere we are seeing flood warnings! Do maintain an appropriate level of attention to the environment around you, regardless of where you live and travel! Keep safe.
Two welcomes and a goodbye
The new publication year sees some changes in the Publications Committee and the Amateur Radio team.
The Publications Committee has a new Secretary, endorsed by the Committee at its December meeting. Kaye Wright VK3FKDW has volunteered to take on the role. Welcome to the team Kaye. Kaye had an easy December, as it is a quiet month for the committee. By now, the magazine email address should be working to send any queries, and all contributions, through to Kaye. Therefore, all contributors can expect to receive an initial response from Kaye.
Thanks to Evan VK3ANI who has filled in as Acting Secretary since September. Evan is also working on some enhancements to the Article Register, which are aimed at making article processing an easier task.
Our second welcome goes to Nick Hacko VK2DX, who joins the team of contributors to the magazine as the new DX columnist. I trust that you enjoy his first column.
And finally a goodbye: Bill Roper VK3BR has been a contributor and member of the Publication Committee for a very long time: he has been involved in several roles since 1963! Whilst he has not attended the regular meetings of the Publications Committee for some time, he has always contributed well-considered opinions whenever we have asked members any questions.
Of recent years, Bill has tweaked many of the images submitted for publication and has prepared many excellent line drawings and circuit diagrams. The need for both roles has reduced in recent times. At this time, I am not sure how we will deal with the issues of circuit diagrams in the future. We still occasionally receive hand-drawn diagrams. We may well need to call for someone to take on such tasks.
Bill has certainly done much more than his fair share of work to contribute back to the hobby. A key component of the success of technical articles published in Amateur Radio has been Bill’s excellent artwork, giving a consistent style which is easy to read and comprehend.
On behalf of all readers, I offer my sincere thanks to Bill for his contributions over 52 years.
Until next month,
Cheers,
Peter VK3PF
This month’s cover:
The New Year is always busy for VHF, UHF and microwave enthusiasts in Australia, with the Ross Hull Memorial VHF-UHF Contest and the Summer Field Day both occurring in January. We often see days with stable enhanced tropospheric propagation conditions. Such conditions were predicted for 5 January 2015. The map shows the approximate paths of the key contacts made on 5 January, including the new World Record contact on 10 GHz between VK6DZ and VK7MO over a distance of 2732 km.
The inset shows Rex VK7MO with his equipment in the field. Photo and graphic courtesy of Rex Moncur VK7MO, with thanks to Google Earth.
WIA President's Comment
Who said home-brew is dead?
For years, my shack has consisted of a collection of eclectic bits and pieces ranging from some old Collins (valve) S-line gear, a home-brew Class-E (MOSFET) transmitter and Class-D (MOSFET) modulator for use on 40 metres AM, as well as an FT-857 that I occasionally use mobile. I also have a Barrett 550 marine transceiver on a sailing boat with some fixed amateur channels programmed-in. My home antenna is an 88-foot doublet with open wire feed line to an antenna tuner in the shack; on the yacht, it’s a 15 metre backstay antenna.
Not very impressive by modern amateur standards, but I’m more of a constructor than an operator, and I get most of my fun from building things. My latest project isn’t even amateur radio: a 60 watt Class-A stereo amplifier using six 6SN7s and six KT120s in a Wiggins Circlotron arrangement, with low turns-ratio output transformers mounted at the speakers. Tragic, I know, but it sounds fantastic and it would certainly make a great AM modulator, but a frequency response of 10 Hz to more than 100 kHz would be a little over the top!
For many years I’ve reconciled myself to the view that maybe I’m a bit out-of-step with the rest of the world and that, apart from antennas and ancillary equipment, home-brew in amateur radio was pretty dead. But, this Christmas I took a look at the “What’s on your Workbench” discussion in the “General Discussion” section of the VK Logger on-line forum. Started by Peter VK3YE in April 2013, the thread is now 17 pages long with a wide variety of home-brew projects ranging across receivers, transceivers and transverters, antennas and amplifiers, and lots more. It’s well worth a look at http://www.vklogger.com/forum/viewforum.php
Projects that particularly caught my eye were: a WSPR transmitter using an inexpensive Raspberry Pi computer; a hand-cranked CW transmitter (which requires the operator to perform the physical and mental feat of cranking a handle with one hand while tapping out intelligible Morse with the other); and a U-Tube video of a home-brew phasing transceiver, all by Peter VK3YE - a very prolific forum contributor.
One thing is certain; the way an on-line construction project is developed and documented is very different to a traditional paper publication. What you won’t find are fully documented projects like you would find in publications like Silicon Chip, the ARRL Handbook or in AR magazine – the on-line world is much more dynamic than that – but you are likely to find a project, or the seeds of an idea, that sparks your interest. By publishing on-line, a home-brew constructor can showcase their project right from the start and track how it develops, and there are always lots of people who are more than willing to offer comments, their own ideas or constructive criticism.
Home-brew also came to the fore very recently when VK6DZ and VK7MO cracked the world 10 GHz DX record on 5 January - with homebrew portable gear. Derek VK6DZ and Rex VK7MO have each assembled sophisticated communications systems for 10 GHz and accumulated an understanding of how to exploit long-distance tropospheric refraction; years of construction and planning have paid off magnificently.
So, I now believe home-brew in amateur radio is very much alive and kicking, it’s just not so obvious. I’m sure AR Editor Peter Freeman would love to see a few of those great projects dressed-up a little and submitted to AR for publication to reach a wider audience, or maybe in the future our AR magazine may find a way to mesh with the on-line constructors.
Phil Wait VK2ASD
President
P.S. The WIA’s next AGM will be held in Canberra over the weekend of 9th and 10th of May. The theme this year is celebrating 10 years of the Foundation licence and amateur radio to the future, and there will also be special activities associated with the ANZAC centenary.
Table Of Contents
GENERAL
How much do you want the DXCC? Peter Pratt VK2TTP
Turning clutter in to a collection Linda Luther VK7QP
“Bill” Moore VK2HZ: Writer, WIA President & POW morale booster Peter Wolfenden VK3RV
Closure of experimental and amateur stations WWI & WWII Peter Wolfenden VK3RV
TECHNICAL
A modelling approach to antenna construction - Part 2 Stephen Ireland VK3VM/VK3SIR
A multi-function sequencer Leigh Harrison VK6WA
Plus all the usual Club news and columns
How much do you want the DXCC?
Peter Pratt VK2TTP
All true DXers, and many casual DXers, strive to obtain the ubiquitous DXCC award, for having worked one hundred entities (countries). It is a true benchmark achievement for almost all DXers no matter their future ambitions.
It can also mean a lot of effort as the DXer has to collate those entities confirmed, together with any unconfirmed paper QSL cards he may have, in whatever manner the award may require.
The author’s adventure to achieve just that result is the meat of the article, and is a very interesting, and somewhat amusing, story.
Turning clutter in to a collection
Linda Luther VK7QP
The author is a member of the WIA Archive sub-committee and gives a brief overview of the goals of the WIA archive collection, and how this may be managed to, in her own words, ‘turn it in to an interesting and accessible archive recording the history of amateur radio in Australia’.
This is one of the more worthy tasks facing the WIA, and deserves our robust support.
A modelling approach to antenna construction - Part 2
Stephen Ireland VK3VM/VK3SIR
In this second part of this series of three articles, the author works through the development of the model for the 40 m dipole project and examines the expected performance characteristics of the antenna.
A multi-function sequencer
Leigh Harrison VK6WA
In the typical amateur shack there are to be found many different pieces of hardware and software, used in increasingly complex patterns and combinations, which is where the function of the unit described in this article, a sequencer for controlling timing issues, becomes useful.
The author describes how to fabricate such a unit and provides a parts list, a possible source for those parts and easy to follow instructions.
Note that some Tables and Figures are not reproduced in the magazine due to space constraints. The full article is available to download from the bottom of this page.
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