Adjusting an MSK 007 Leapfrog VCF to its best possible operation involves a tricky process of feeding in a 740Hz sine wave and measuring phase differences between different test points. I also had reason to measure phase differences in my recent experiments on recognizing fake coins. Although my oscilloscope has a mode for measuring phase differences that works well enough, it can be annoying to use, and I thought it'd be a fun project to build a better tool. READ MORE

Here's a little project I put together to solve a specific problem: checking power cables for shorts. I made it using the parts I had on hand, and if you build one yourself you may well end up wanting to make changes, so I'm not going to prepare a complete set of documentation or sell kits or anything. I don't think it's going to be popular enough for selling them to be profitable. But if, like me, you're in a position of needing to check a lot of power cables, you might find these notes useful in designing your own tester. READ MORE