I recently bought two Diamond MX-2000N triplexors because at my current place I only have one space for one RF cable from the shack to the roof. The idea was to have one triplexor in the shack and another one below the antennas. Before installing the triplexors I decided to bring them on the bench and check if the claimed performance is met by the devices.

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Recently my Yaesu FT857 became deaf. It turned out that the plastic enclosure of the FT857 filters over time consensated moisture which ruined the filters. In this post I’ll show you how I replaced the filters and brought the radio back to life.

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My standard development environment was for some years a 24” standard HD monitor together with the 15” Retina display from my Macbook Pro. Recently I felt more and more frustrated about continous window tabbing. The available screen estate was just not enough anymore.

In my search for a bigger screen, I wondered if it wouldn’t be possible to use a 4k TV instead of a pair of > 28” PC monitors. The advantage of the 4K display is of course its resolution of 3840px x 2160px and much more afforable price than a comparable set of PC monitors.

There are several things to consider when upgrading to 4k displays, but in my case, everything worked out well - almost out of the box. I couldn’t be happier with the result!

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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 appart. 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 which 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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A few years ago I migrated almost entirely to OSX & Ubuntu. However I still had to maintain a Windows copy on one of my harddrive partitions, since a few applications were just available for Windows. In particular, DG8SAQ’s superb Vector Network Analyzer (VNWA) software. I can already use most of the applications in a Virtual machine, with the benefit of not having to reboot and change the OS, but DG8SAQ’s software with it’s USB I/O always gave me hard time. Finally I figured out what need’s to be changed. Now the VNWA runs also smoothly in a Virtual Machine.

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Author's picture

Tobias Wellnitz, DH1TW


Software Engineer

Germany