At our Contest Station ED1R we are limited in space. Therefore we have to install before the contests our low band verticals and beverages - and of course, after the contests, take them down and bring them into the storage again. Over the last years, we started optimizing the way how to rapidly deploy and remove radials. Earlier we used a bunch of garden hose carts, which were inexpensive, but after three contest seasons, they started falling apart. A more solid solution was needed. This time we build a solid cart, using surplus military equipment.

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Once your contest station grows bigger and you add more antennas to turn, it becomes quite annoying to move around the physical rotator controllers between the operating positions inside the shack. Desperate for a better solution, I developed a server software that provides access to the Rotators through the network. Now all rotators can be controlled either directly through Win-Test, TCP socket, or through a Web-Interface.

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At our contest station ED1R we have no space for permanent Lowband Verticals. Each Contest, the verticals have to be installed temporarily in a field nearly. Especially the deployment and removal of the antenna radials are very time-consuming. Over time we optimized our system which reduced the required time from 2 hours down to 30 minutes.

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Over the last few years, I spent a lot of time simulating antennas. One annoyance I encountered over and over was the unavailability of values for ground conductivity and the relative permittivity. Two figures have quite an impact on the antenna performance, especially on vertical antennas. This finally led to the conclusion that both figures need to be measured. In early 2012 I built a measurement kit and finally determined ground conductivity and relative permittivity at our contest station.

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Author's picture

Tobias Wellnitz, DH1TW


Software Engineer

Germany