Speaker

August 25, 2020: Jim Marr AA6QI: Antenna Analyzers, Feedlines, and Antenna Tuners

PLEASE NOTE: Because our meeting location is unavailable due to the coronavirus situation, this presentation will be webcast on the internet. See the IMPORTANT NOTE at the top of this page.

Our August 2020 speaker will again be Jim Marr AA6QI who will talk about Antenna Analyzers, Feedlines and Antenna Tuners.  The suggestion for this talk came from PRC member Gus, N6UQ, several months ago.  In this talk, Jim will discuss some of the currently available antenna analyzers, including options and features, including some cautions to be aware of when using any antenna analyzer.  He will discuss some of the things you can do with an antenna analyzer besides measure SWR, including characterization of feedlines (length, characteristic impedance, velocity factor, loss & fault location).  He will also discuss what antenna tuners do and how they do it. To enable some of this discussion, Jim will provide an overview of the Smith Chart and present results using Smith Chart plots derived using SimSmith.

Jim Marr AA6QI has been licensed since 1965 (formerly WB6LOA), but was relatively inactive through a substantial part of his working years. He is actively enjoying the hobby again since his retirement in 2015. Jim has a BS in Engineering and Applied Sciences, and an MS in mechanical Engineering from Caltech. He spent seven years with the U.S. Navy operating submarine nuclear propulsion systems, and four years with Tetra Tech, Inc., leading their Marine Systems and Services Department. He was with NASA’s Jet Propulsion Laboratory for 31 years, mostly in line and project management. A most significant experience was leading the team that reprogrammed the Galileo Jupiter mission spacecraft while in flight to Jupiter, while simultaneously redesigning NASA’s Deep Space Network to support Galileo’s mission at Jupiter using its S-band 7 dBi low gain antenna after its X-band 43 dBi high-gain antenna failed to deploy.