June 23, 2020: Jim Marr AA6QI: Troubleshooting methodology with examples

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.

This month's speaker is our club’s vice-president, Jim Marr. Jim will describe a systematic approach to the troubleshooting of problems in electronic equipment. To demonstrate the methodology he will use a couple of recent examples involving the failure of power supplies at the local W6MPH repeater. He has also tested the methodology in restoring a bunch of older ham gear recently received from an estate. Jim’s approach is modeled on his many years of experience with NASA. In the past, he led the Flight Electronics Group in the Guidance and Control Section and was Section Manager of the Command and Data Systems Section, both at JPL, which involved working through many hundreds of Problem/Failure Reports (PFRs) that document issues identified during spacecraft flight electronics testing. Closure of a PFR requires careful systematic demonstration that the problem has been correctly identified and the corrective action completely verified. This experience carries over into Jim’s approach to his ham electronics troubleshooting and repair, which he will discuss in this talk.

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.