The Carrington Event

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At 11:18 am on September 1st 1859 the English astronomer Richard Carrington in his observatory was recording sunspots on an image of the sun projected through his telescope onto a screen. Carrington in his report noted “Two patches of intensely … Continued

Notice of Annual General Meeting

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Members,   The 2017 DARC AGM will be held on Wednesday 1st March 2017 at the Knuckey Lagoons Recreation Reserve commencing at 1900Hrs   Attached is the formal notice of the meeting (as required by the DARC Constitution) with Proxy … Continued

NEWSWEST Amateur Radio News

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Another great place to get Amateur Radio News http://www.vk6.net/ The NewsWest broadcast happens every Sunday morning at 0930 WST following the 0900 National News.  The news is transmitted through the linked repeater network, originating on VK6RAP 146.700,  and various HF … Continued

The humble half wave dipole antenna

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Many amateurs think that the half wave dipole antenna has a 50 ohm feed point impedance! From Wikipedia “A true half-wave dipole is one half of the wavelength λ in length, where λ=c/f in free space. Such a dipole has … Continued

What is so special about 50 ohms?

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Have you ever wondered why most of our Amateur Radio equipment is designed for 50 Ohm transmission lines? The following graph was originally produced by two researchers, Lloyd Espenscheid and Herman Affel, working for Bell Labs in 1929. The graph … Continued