Gillies 3
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Copy of Telefunken Catalogue picture of Model E4 very similar to the photo of the Macquarie Island equipment. Tsommitting set for medium sized and large ocean __ liners and for land stations. / Series spark gap of eight sections —_ for regulation of energy. / Three fixed waves between 300 and 600 meters. / The trans- mitting set includes 3 kVA- motor - gene ~ rator set and aerial tuners. / For two 60 to 120 ft masts at a distance of 120 to 240 ft the guaranteed range across the open sea is 140 to 325 miles. / A suitable receiver is our type ES (see section A, group IV). Copy of section of Telefunken catalogue with the English text for the type of transmitter unit as seen in the AAE pho- tos. worked in Germany, who might know of a Telefunken Museum. He suggested writing to the Australian ambassador there, explaining my search. I received a reply from Regine Pankuweit, Research Officer Economics/Technology at the Australian Embassy in Berlin, with the Email addresses of two possible con- tacts in Germany. The first was a Telefunken Museum in the city of Ulm, the other, the German Museum of Technology in Berlin. When I contacted Fritz Arends at the Telefunken Museum and explained what I was after (circuits and construction details of the 1911 equipment), he replied that all the paperwork had gone to the Museum in Berlin. However, he found a photo of the equipment in the German publication, ‘The German Radio Systems until 1945’ (3 volumes), describing the first 40 years of radio systems. He offered me the set of books, but they were all in Page 24 - Aurora - December 2008 German, so I asked him to scan the pages of the section relating to the 1911 equipment. (See picture on the previous page.) When I contacted Herr Hoppe, at the German Museum of Technology in Berlin, he advised that they did have some equipment of that era that was being restored. As I had planned a trip to Europe later in the year, I rearranged our trav- el plans, to spend a day in Berlin. I was fortunate to find a receiver unit that had just been restored, still in the conserva- tor’s workshop and was able to examine it closely and take many photographs. It was a later version of the same unit, but it gave me an idea of the sizes of the unit. Herr Hoppe said that they had some of the transmitter parts stored at another site, so I was not able to see them. However, I was able to look through the archives of the Telefunken papers and old catalogues to see equip- ment that matched the Hurley/Sawyer photos. The earliest that the papers went back to, was 1917; some of the pic- tures were very similar and had circuits that I was able to understand. When I saw the receiver unit, I was surprised at the complex rotary knife switching mechanism, that is not visible in the AAE photos and the aerial changeover switch that was operated by a lever, like the old one-armed-bandit poker machines. Some of the contacts that are operated by this handle, switch the detector diodes out of the circuit when the unit is in transmission mode and apply power to the transmitter unit. I can see how condensation in the cold workshop room, could easily have built up a film of ice in these switches and not be noticed because they were at the back of the unit. This could explain how contact with Macquarie Island was first made in late February, when the room may have been above freezing for some time and later, when the set was brought into the main hut where it was considerably warmer; it would also have prevented the build-up of ice on the switches. For some time while researching the fate of the original wireless set, I had been on the look out for suitable materi- al to use to build a replica of the spark gap transmitter. The Leyden jar con- densers (early capacitors) were a big problem. I had no idea of the size neces- sary, only a rough dimension scaled from the photos. I had found plans of a Quenched Spark Gap unit on the inter- net. When I first saw the switching mech- anism on the receiver unit, I thought that it would be too difficult to replicate it. However, after studying the photos I had taken, to figure out how everything worked, I began looking for material to Antenne Sekundar Model 5E receiver that has just been restored in Berlin. — Photo by John Gillies Back view of restored Model 5E receiver unit in Berlin. — Photo by John Gillies use to make the wireless set as similar as possible. I analysed the photos I had taken and scaled the transmitter unit from the catalogue dimensions of the Leyden jars and the dimensions of the receiver unit, I thought I would have a go at constructing a replica for the Centenary of the AAE in 2011. Fortunately the ANARE Club President, Brian Harvey, has a large col- lection of material in his factory, togeth- er with a large lathe that has enabled me to get started on building a replica. To be continued.