Current bugbears

[Jerry Van Baren]

IIRC, the radio receiver ban dates back to when relatively inexpensive 
aircraft band receivers (things passengers took on board, not the radios 
the airplane was fitted with) were often regenerative/superregen and 
thus interfered with aircraft communications if mis-adjusted (and were 
often mis-adjusted by John Q. Public).  After a few incidents where 
passengers took radios on board to listen in to the aircraft 
communications and inadvertently *prevented* aircraft communications, 
all radio receivers were banned.

<http://en.wikipedia.org/wiki/Regenerative_circuit>

There is tremendous inertia in relaxing restrictions once in place, 
especially where safety was once involved.

Best regards,
gvb


Claes Mogren wrote:
> I call bullshit on this signal restriction. How come they've 
> successfully had wifi on planes without any problems? And I know that 
> people have their phones on all the time while flying and I've never 
> heard that it has caused a crash or even been noticed in any way. Can't 
> imagine that there's any GSM signal to pick up a 30000ft anyway when you 
> move at 800km/h.
> 
> Also, if GPS is bad for the planes, how come the US is going to use it 
> to navigate the planes?
> (http://www.theregister.co.uk/2007/09/04/gps_satnav_air_traffic_for_america/ 
> <http://www.theregister.co.uk/2007/09/04/gps_satnav_air_traffic_for_america/>)
> 
> Anyway, back to OpenMoko. I agree that it's good to have the option to 
> turn all wireless communication off on boot, with a timeout of 10 
> seconds or so. Default should be the same settings as you had when you 
> turned off though.
> 
> Regards,
>  Claes Mogren
> 
> On 9/4/07, *Richi Plana* <myopenmoko at richip.dhs.org 
> <mailto:myopenmoko at richip.dhs.org>> wrote:
> 
>     On Tue, 2007-09-04 at 10:27 -0700, John Seghers wrote:
>      > Part of the process of receiving signals involves
>     heterodyning--basically
>      > mixing a received signal with lower intermediate frequencies (IFs) to
>      > amplify the desired actual signal, while making the carrier
>     signal something
>      > easier to work with. See http://en.wikipedia.org/wiki/Heterodyne
>     for a very
>      > basic description.
> 
>     Fascinating. So "passive receivers" really aren't? Or are there classes
>     of receivers which are (no amplification or very sensitive pickups)?
>     Prolly off-topic, but I sure am curious. Are there no radar detectors
>     which don't give off their presence?
>     --
> 
>     Richi Plana
> 
> 
> 
> 
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