"RadioActive - First Light for RadioTelescope at Wiruna"
A Special Report - Lorraine Mencinsky

A slight departure from the usual this month, to report on the latest progress. As Joe and/or Scott might have reported, the September New Moon was a very favourable one (perhaps 1 3/4 clear nights on the Cauchi scale), with warm clear days and little wind. All of this allowed a great deal of work to be performed on the radio telescope.

Before going any further we must immediately pay tribute to local member Roger Heap, who spent most of the entire weekend on this work. Roger's unstinting donation of specialized tools, equipment and sundry componentry, but even more importantly of his tireless energy, time and enthusiasm, allowed us all to make huge progress.

Many hours were spent in further cleaning, rust removal, painting, lubrication and bolt replacement. This task, seemingly endless to begin with, now appears to be approaching completion. As a part of this, dish/mount components for which we anticipate no future use were removed and stored in the no-longer-used external shower. The central "tower" was lifted up onto the dish and bolted on; and much of the radio-transparent plastic superstructure connected to that.

In the electronics arena, there was also much achieved, much more than was anticipated. The WinRadio module was powered up and connected to the laptop computer for the first time under field conditions: we all enjoyed listening to the local FM radio station (KRR, I seem to recall?) and looking at its spectral display. We then connected one of Roger's UHF aerials placed at the focus of a 70cm safety mirror and aimed at the sun. Unfortunately, no signal was detected. Undaunted, we moved on.

The Low Noise Amplifier/Converter (LNC) was powered up for the first time and demonstrated to be working as specified. Roger demonstrated what was perhaps his most creative work of the weekend, making up a temporary feedhorn and mount literally out of aluminium foil, a cardboard box, duct tape and a piece of plastic water pipe. Readers who recall the "Carbon dioxide scrubber" scene from the movie "Apollo 13" may well appreciate how this all appeared. We were then ready for the first end-to-end test of what was now a complete system: dish, feedhorn, stub antenna, cabling, LNC, WinRadio and computer. With an enormous collaborative effort by all concerned, the vast logistics exercise of putting all of this temporarily in place was achieved. It was quite a thrill at night time to see the silhouette of the mighty dish and its microwave electronics aimed squarely at the galactic centre during the Saturday night and then at the Sun on Sunday morning! During this time President Buckley took many photographs of the various stages of construction from a variety of odd angles, threatening to introduce carefully selected croppings of said photos into a variety of compromising situations.

Regrettably, the results were somewhat disappointing. The electronics were demonstrably working to perfection, yet no signal was achieved, not from Sagittarius, not from the Sun. Subsequent analysis of our feedhorn later showed that the water pipe was too small in diameter to work at 1420MHz; something that we could not have gleaned on site since our feeble laptop does not have the XL Spreadsheet program for feedhorn analysis installed.

One final test was performed on Sunday, the use of another (unfortunately somewhat suspect) aerial to attempt to detect the Sun at a slightly lower frequency, at around 500MHz. This test, it seemed, succeeded. Faint spikes were detected in the radio spectrum when the dish was pointed at the sun; these disappearing when the dish was moved elsewhere. We rotated the dish to expose the bare antenna to all parts of the horizon in case the signal was terrestrial in nature (there are many and varied FM and TV stations in that part of the spectrum), but nothing was detected: only when we were pointed directly at the Sun was there any signal. So it seems we were successful.

The unsuccessful attempts are mentioned here quite deliberately. A project such as this, even though we strive to avoid experimentation as much as possible, is by its very nature going to have many false starts and produce many initially misleading results. That does not imply "failure" in any way. It needs to be clearly understood that this kind of project is galaxies apart from purchasing an expensive warrantied and guaranteed shrink-wrapped and with instructions consumer electronics unit from a large retailer, where there is a clear and realistic expectation that all the parts are included and will integrate and work perfectly on the first attempt.

What next? Many operational lessons were learnt and many dead ends were discovered. Weather and fate permitting, more permanent equipment will be constructed between now and the October New Moon at which time we hope to make another attempt, to be later reported in "Universe" and on the Web Site. Stay "tuned".