Speaker

February 27, 2024: Jim Marr AA6QI: Antenna tuners

PLEASE NOTE: Our monthly general meeting is IN-PERSON, as well as webcast on the internet. See the notes at the top of this page for details.

Our monthly speaker once again is Jim Marr AA6QI, who will discuss Antenna Tuners. This is part three of his three part discussion of Analyzers, Feedlines and Tuners. The talk will discuss the characteristics and effects of RF reflections due to mismatched feedline-to-antenna impedances and how antenna tuners deal with the reflection to result in tuning the entire system to resonance, resulting in all transmitter power reaching the antenna (less feedline losses).

Jim Marr AA6QI has been licensed since 1964 (formerly WN6LOA, then WB6LOA), upgrading to Extra Class in 1989 (when 20 wpm CW was still required).  While relatively inactive during much of his working career, Jim 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, mainly 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, simultaneously redesigning NASA’s Deep Space Network to support Galileo at Jupiter using its S-band 7 dBi low gain antenna after its X-band 43 dBi high-gain antenna failed to deploy.