I've been watching this discussion with interest. It appears you are agreeing with each other - at some length. (grin) The subject of interference to airborne navigation and communications receivers seems never to go away. Since it was the probability of just such interference which lead the FAA to impose its PED regulations, this is perhaps appropriate. I have seen emissions from non-ITE PED's (CD players) that greatly exceeded the FCC class B limit, and it is not unreasonable to expect interference to receivers from many kinds of device.
I seem to recall mention in one of the EMC magazines (Conformity?) a couple of years ago about a GSM telephone *in checked baggage* having been identified as causing direct EMI to aircraft systems. This, apparently because GSM amplitude modulation is more conducive to rectified logic upset than a steadily emitting frequency-modulation. And of course the hold is NOT a typical location for customer-carried PED's. There was also mention further back (this may be on the FAA Web site - a useful compendium of reports) of a test in which a handy-talky of some type was, as an experiment, used to transmit inside the cockpit of an airliner, with noticeable upset to instruments at the flight engineer's station. This could be direct interference from a PED, though hardly _likely_ in flight, especially with today's security restrictions on where passengers may go. I personally recall an incident about 7 years ago in which a product of my then-employer, a laptop computer, was reported to have caused an aircraft on a long over-water flight to take a left bank of two degrees, which trim upset went away when the computer was turned off. However we were unable to identify emissions which could have caused this. I do not believe that passenger AC power, MOST likely culprit, was provided at the time, so that seems to be ruled out, and the energy in the LCD backlight inverter was far enough away from wiring that it SHOULD not have done so. Cortland ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
