Category: Blog

As expected, the antenna did not perform as modeled on my balcony. I think my F/B ratio is not great, but I seem to have a strong beam towards CA / NM / AZ. Once I mount it above the railing, I should be able to turn it , but I’m guessing South will always…

I took some measurements of my balcony, and modified my EZNEC file, adding some straight sections at the end. The goal is to make it easy to disassemble and tune, so I bought 4 cheap telescoping sections (max length 74 cm) from Amazon (4 pack for $12). EZNEC says the reflector should only be 4…

Years ago, (probably the late ’90s) I played with EZNEC and haven’t really used it much… until today. I was trying to find information on reduced size yagis using meander techniques. There really wasn’t much out there, so I tried my own. Ignore the W8JK name – I guess I forgot to update the comments…

The idea is to design a clean switch-mode power supply that can envelope-track (class H) a SSB or digital narrow-band signal, and use it to drive a Class F ultra-low-loss amplifier with some extra harmonic filtering. Simulations look pretty good, except for how sensitive it is to reactive loads. Targeting 20 meters, 1 kW, >85%…

For most of my career, the goal has been isolating from magnetic fields coupling where they shouldn’t, so building something to intentionally radiate was a refreshing change of pace. Design I already had some 4 inch aluminum tape and 1 inch copper tape. My first thought was to cover some PVC pipes, but I didn’t…

If you’ve ever tried to simulate a circuit using nothing but paper and pencil, or tried to match your antenna to 50 ohms by making an educated guess, you’ve probably found yourself looking for some of these tools. Everyone has their favorite tools. Here’s my list! Impedance Matching https://www.analog.com/en/design-center/interactive-design-tools/rf-impedance-matching-calculator.html Just a handy, free calculator when…