S11 (return losses) is another expression for SWR (standing waves ratio) and IMO a better one. It is the ratio of port #1 to port #1, in other words, what comes out of port #1 relative to what you injected in port #1. When you send power to an antenna, some of it is reflected […]

This is an aircraft light I designed a few years back. I decided to make a tutorial for it so others can make and hopefully continue to improve the design. The light is base around CREE’s XM-L or XHP-70 LED. Supply list: CREE X-ML2 or XHP70 mounted on 20mm copper MCPCB. 20x20mm star shaped heat-sink. […]