Speaker

January 23, 2024: Jim Marr AA6QI: Antenna feedlines

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.

This month’s guest speaker will be Jim Marr AA6QI giving Part 2 of his three part talk “Analyzers, Feedlines & Tuners”.  Part 1 about antenna analyzers was given at our November 2023 meeting and is still available on Jim’s DropBox at the link previously distributed (send Jim an email if you need that link again — aa6qi (at) arrl (dot) net).

Since the Smith Chart is an essential tool for discussing feedlines and tuners, Jim will begin Part 2 showing how the Smith Chart is derived and will briefly demonstrate its use using a computer program called SimSmith. Then Jim will discuss the various types of feedlines and their properties, connectors to use with them, how to measure feedline properties using your antenna analyzer, and how to verify that your feedline is ok to use.

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.