I created a device to assist in morse code transmission, commonly called a keyer. It has nearly all the features you'd expect from a keyer, and can be built for less than $40 including project box (but not including the key or the radio of course). The source code is open and the schematics are available later in this article. All I ask is you let me know if you build one too!
I want to start better documenting my cheese-making efforts, beginning with this tomme I started Feb 2, 2017. This is mostly just for my own reference, but I've been asked before about my technique, so you might find it interesting. Just ask me if you have any questions!
Daniel Lemire has written an interesting blog post entitled Counting exactly the number of distinct elements: sorted arrays vs. hash sets?. I've used Judy arrays for similar tasks in the past and was curious how they would stack up, so I've taken Daniel's code and modified it slightly to measure this.
Sorry to disappoint people who come here for radio content, but this post has nothing to do with log-periodic antennas. On the other hand, for anyone who comes here to read about neat software stuff I'm working on, please keep reading!
In April 2009 I wrote up a simple utility over a weekend called
vmtouch. It helped me solve a few problems I was experiencing on the job and, most pressingly, let me run a series of experiments to satisfy my curiosity about how the filesystem page cache works. I have found
vmtouch very useful over the past 7 or so years, and apparently a few other people have too.