Speaker

July 28, 2026: Jim Marr AA6QI: Building and using a quadrifilar helicoidal antenna for working amateur satellites

PLEASE  NOTE: We are currently meeting at our standard location for in-person meetings, the Kaiser Permanente Walnut Center in Pasadena. Our monthly meetings are also viewable on Zoom. (See top of this  page for details.)

This talk by club member Jim Marr AA6QI follows last month’s Field Day 2026, when some PRC members experienced working amateur satellites with Carol (KE6SRN) and Tom (KE6SRO) Bruegge and might now be thinking about how they can work satellites themselves. This month’s talk addresses an alternative, specialized use-case of working satellites from a home QTH using a quadrifilar helicoidal antenna (QHA). The talk will cover deciding what to build for satellite antennas, designing the antennas, building them, testing and troubleshooting them, configuring an entire station, and finally using/evaluating the antennas/station to find out how well the whole arrangement works. 

The is a modified version of the presentation that Jim gave in 2016 when first developing QHA antennas and setting up his satellite station.

Jim began his amateur experience in 1963 as Novice WN6LOA, upgrading to General WB6LOA a few months later, then finally upgrading to Extra as AA6QI in 1989. He has been active in the JPL Amateur Radio Club since the early 1980s and the PRC since 2014. Jim is a US Navy veteran (nuclear submarines) and was a long-time JPL engineer/manager (now retired). He holds a B.S. in Engineering and Applied Science and an M.S. in Mechanical Engineering (dynamic systems control), both from Caltech.