I recently bought two Diamond MX-2000N triplexors because at my current place I only have space for one RF cable from the shack to the roof. The idea is 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.
Recently my Yaesu FT857 became deaf. It turned out that the plastic enclosure of the FT857 filters over time consented to moisture which ruined the filters. In this post, I’ll show you how I replaced the filters and brought the radio back to life.
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.
At our Contest Station ED1R, we have on each highband 3 Yagis available. In 2012 I built 4 high-power Stackmatches to switch and combine them properly. Since I never liked the way of WX0B’s stackmatch controllers with the rotative knob, a microcontroller and button-based solution were the answer. After a few contests, the solution has proven its reliability and comfort.
One of last year’s projects was the improvement of our Contest Station ED1R. For the various Yagis, we needed smart ways to combine antennas. Instead of buying commercial stackmatches (antenna combiners), I decided to build them up by myself and adjust them to our needs.
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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