There may be another possibility for such a ban , that is not related to any RF signal interference. It might be some left over residue of the 911 paranoia. ----- Of all the things I have lost ----- -------- I miss my mind the most -------- Team Nine Lives wrote: > As AZcachemeister said, receivers also typically transmit, usually on > some harmonic frequency of the transmit frequency. AM and FM radios > are dangerously close in the spectrum to airline frequencies (close to > FM, but the signal has AM characteristics in the carrier method, as I > understand it--doubtless ShadowAce or somebody will fine tune this if > it isn't accurate). > > There are reports that some spies have been detected based on > detection of the transmitter elements of their receivers. > > So the "logic" probably goes like this: Since radio receivers also > transmit, they might interfere with aircraft electronics or > communications. A GPS receiver is a radio receiver, so it too must be > capable of interfering. Ergo, we can't allow it. (Never mind the > details of the frequency and modulation....) Perhaps now somebody is > doing some actual RF emissions testing and deciding GPSr's are > acceptable. > > On Fri, Mar 21, 2008 at 5:00 PM, Bill Brightman > wrote: > > Does anyone have an idea of the logic behind banning use of GPS > units in flight? > I can see why devices which emit a signal, like a cell phone, > could be suspected of possibly interfering with the plane's > electronics. But it seems like a GPS would be more along the lines > of an MP3 player or something. Just wondering if I'm missing the > point here... > > Bill B. > > > ------------------------------------------------------------------------ > > ____________________________________________________________ > Az-Geocaching mailing list listserv@azgeocaching.com > To edit your setting, subscribe or unsubscribe visit: > http://listserv.azgeocaching.com/mailman/listinfo/az-geocaching > > Arizona's Geocaching Resource > http://www.azgeocaching.com >