A Growing Concern
When it comes to understanding the performance of HF antenna systems, there are only a few tools. You can measure the impedance match with an antenna analyzer, you can model the antenna to see what you might expect the antenna to do, and you can listen and talk on the air to see how well [...]
My bamboo pull-up hex beam has been a work horse antenna for the last couple of years. It underwent a few changes from the initial design. I removed the 30 meter wires because the antenna was just too large to turn easily and get up and down between the branches with the space needed for [...]
After a two-year Covid hiatus, Burning Man was back for 2022. We planned this year to stay for the entire event including the temple burn on Sunday evening. The weather was very hot and dusty, but the art was hotter. Our Playa Home The first dust storm destroyed the pop-up shade garage. But the rest [...]
With Burning Man in the future, the DateTrikE needed to be off the grid, the trike's cloth canopy to be replaced with solar panels. This is all mildly expensive, so I wanted the solar canopy to be able to do double-duty as solar for our RV. The canopy needed to be lightweight but still robust. [...]
After more than twenty years of growing squash here in Eugene Oregon, I never saw a squash bug (Anasa tristis) until two or three years ago. Since then they have become much more common and there have been reports from many local gardeners having to deal with them. I knew what they were, however, because [...]
When the DateTrike made its debut ten years ago, electric bikes were still just a curiosity. But times change, technology advances, and today e-bikes are the rage. I have been considering adding some electric assist for awhile now. I'm not as young as I was ten years ago, and the hills are just as steep. [...]
With the world atwitter over a new coronavirus variant, it seems a good time for armchair epidemiologists to take a look at what is coming. Before we dive into Omicron, lets look back at the Delta surge, and before that Alpha. The figure above from the New York Times shows US new cases since the [...]
PSK Reporter is really a very cool program that collects reception reports from a myriad of users and displays the results, filtered in just about anyway you can imagine, on a map on your computer screen. I use it all the time to help me understand which parts for the world are open to communicating [...]
After doing the ferrite transformer scaling experiments last time, and learning a bit more about what matters in these transformers, it was time to make a stab at designing one. Let me review the salient observations from the previous work. 1) More primary turns and primary inductance improve the transformer efficiency and low end performance. [...]
There are quite a few recipes for building a suitable transformer for an end fed half wave antenna (EFHW), but I was never sure I really understood the main principles. So, I wound a bunch of transformers, made measurements on them using my NanoVNA, learned how to get what I really wanted out of the [...]
Squash Practice 