At ED1R we use industrial ball bearings on our towers to turn the antennas. The ball bearings are reliable IF you protect them properly. We learned this lesson the hard way. After almost three years in service, I feel confident sharing our solution for adequately protecting the SKF bearings on antenna towers.
Some years ago, SDR-Kits used to sell a small prototyping PCB perfect for experimenting with a Vector Network Analyzer. After many experiments, the female pin headers on my prototyping board wore out. Since SDR-Kits no longer sells it, I designed my version of this PCB. The KiCad sources of the VNA prototyping/test board are available on my Github profile.
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!
