DIY Spark Gap Transmitter

Simple spark gap transmitter built from a handful of components on a acrylic glass base

This article plunges you into the mesmerrizing world of early radio technology through the assembly and analysis of a DIY spark gap transmitter. This project offers a practical insight into the fascinating dynamics of damped harmonic oscillators and explains charasteristics such the logarithmic decrement, decay rate, damping factor, q factor, and beyond. Prepare to spark your curiosity in a technology that once revolutionized global communication.

DIY: Adjustable 30 kV High Voltage Power Supply

Spark-gap transmitter used for testing the high voltage power supply

High voltage power supplies can open interesting doors to research topics such as laser, x-ray, spark gap transmitters. And many other specialized niches. Unfortunately, laboratory grade high voltage power supplies are rather costly. Luckily, there is a much less expensive way to put high voltage experiments into the hobbyists reach. This article shows how to build an inexpensive and adjustable 5 kV to 30 kV high voltage supply from a commercial laser supply.

Critical length of a PCB trace and when to treat it as a transmission line

SAW filter PCB with SMA connectors for 1090 MHz (ADS-B). Mismatched input and output traces (Z=100 Ohms, l=3,5mm) have been deemed acceptable.

Ideally, the impedance of PCB traces should be matched to the load and source impedances. This becomes especially important in high-frequency and high-speed digital PCB designs. Various rules of thumb are available to determine the critical length at which a PCB trace should be treated as a transmission line. Below this critical length, an impedance mismatch can safely be ignored. Or can it?

Universal Clock Translator using Renesas VersaClock 6E Devices

Programming Kit for VersaClock 6E devices, such as the 5P49V6965 and 5P49V6975

Due to the popularity of the QO-100 geostationary amateur radio communication satellite, precision GPS reference frequency sources (GPSDO) are becoming more and more common in home labs. The desire to derive different, fixed frequency signals from a GPSDO has similarly been increasing as different devices requiere different reference clocks with different frequencies. Therefore, this article is taking a closer look at the VersaClock 6E devices from Renesas.