Meeting Review, November 17, 2010
11/17/10
Meeting Highlights Topic:�������������� Audio in an RF World Presented by:��� Scott Brumm, Roger Grinnip, Mike Moffit, Marty Reiling The November 2010 meeting of the Chicago AES Section was
held at Shure Incorporated, located in The presentation started with acknowledging the challenge that audio developers have with the proliferation of wireless devices in our lives.� �Ambient RF from broadcast sources, personal communications devices, data signals, and a host of others all have a direct effect on audio products. � The �yakkitta-yakkitta-buzz-buzz� of interfering RF signals being demodulated in an audio product was demonstrated by holding a GSM enabled phone within a few inches from an �unprotected� device.� Then the phone was held close to a �protected� or immune device and the audience cheered when no audible interference was detected.� The presenters
related their experiences in addressing interference and signal disruption
and offered various design considerations and test methods. They reviewed
several lessons that they learned as key takeaways such as �copper tape is
your friend�consider it RF duct tape�, avoid � wavelength product dimensions,
and proper shielding and wiring practices are critical � double serve shield
with foil was found to provide the highest level of immunity. Many
great questions from the audience were posed ranging from options of
simulating the interference in an anechoic chamber, the level of involvement
the FCC has provided in terms of testing the GSM affect on devices,
investigating the full RF spectrum that created the GSM interference, and
various shielding considerations such as using conduit for cable runs to
questions regarding the product/project design and cost limitations when
considering dimensional changes to address immunity. The
Chicago AES Section would like to extend a special thanks to Scott Brumm, Roger Grinnip, Mike Moffit, and Marty Reiling for a
wonderful presentation and interactive discussion. |