Sometimes household appliances cause (significant) electromagnetic interferences in our receivers. Unfortunately, replacing them isn’t always an option. Fortunately, adding common-mode chokes to the input and/or output cables can drastically reduce the emitted interferences. Choosing the right ferrite material is probably the most important success factor. In this post, I compare three different materials and show how you can measure and evaluate (random) ferrite cores by yourself!
Both ICOM radios, the IC7300 and the IC9700 allow a variable transmission (TX) delay. This comes in handy if external peripherals like amplifiers and/or pre-amplifiers are used. These devices often have slow mechanical relays. It is good practice to wait until the complete transmission chain is ready before RF is applied. Out of curiosity, I measured and verified the adjustable tx delay on both radios.
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.
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 continuous 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 affordable 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!
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.
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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