involve the airplane's actual instruments. However, though I have a
passing interest in radio, I am not an engineer, so I yield to your
authority.
Personally, if it keeps me from having to hear a hundred iterations
of "Hello, Nancy? Can you hear me? CAN YOU HEAR ME NOW? Guess
where I'M calling from?" during my next flight, I'm all for
continuing the ban.
-- Bill
On Jun 1, 2006, at 4:53 PM, Christopher Erickson wrote:
> With all due respect, YOU are missing the point. Even though the
> avionics
> themselves may be shielded, the GPS receiving antennas obviously can't
> be. Otherwise they wouldn't be able to pick up the faint GPS
> satellite
> signals.
> And it is at the antenna that the signal interference would take
> place. The
> first through fourth harmonics of the cellphone signal (depending
> on which
> of the four RF bands the phone is operating on) sits right on top
> of the GPS
> band and make it very difficult for the avionics to pick up the
> weaker GPS
> signal. Sort of like trying to have a conversation with somebody
> in a tiled
> health club shower room while someone else is loudly singing in
> between.
>
> FWIW, I design RF networks for a living so I feel comfortably
> qualified to
> speak on this subject.
>
> -Christopher Erickson
> Network Design Engineer
> 5432 E. Northern Lights Blvd., Suite 529
> Anchorage, AK 99508
> N61° 11.710' W149° 46.723'
> www.data-plumber.com
>
>
> On 6/1/06, Bill Sheehan <[EMAIL PROTECTED]> wrote:
>>
>> You're missing the point.
>>
>> IN THEORY, IEEE is correct. Mobile phones and other consumer
>> electronics produce radio emissions, some of which are THEORETICALLY
>> capable of interfering with navigation.
>>
>> IN PRACTICE, airline systems are shielded. You may not take a
>> cigarette lighter on board with you, because the pressure difference
>> may cause unexpected results; a defective lighter may explode (and
>> you can't smoke on board in any case). They let you take mobile
>> phones on board, but restrict their use. If there were any real
>> danger of a mobile phone causing problems, you can bet your
>> plastique-
>> soled booties that you wouldn't be able to take it on board.
>>
>> -- Bill
>>
>>
>>
>> On Jun 1, 2006, at 4:00 PM, Christopher Erickson wrote:
>>
>>> First, the Mythbusters episode had nothing to do with the IEEE story
>>> and the research it reports.
>>>
>>> Second, the interference is caused by obscuring the reception of the
>>> faint GPS signals, not by directly disrupting the avionics.
>>>
>>> -Christopher Erickson
>>> Network Design Engineer
>>> 5432 E. Northern Lights Blvd., Suite 529
>>> Anchorage, AK 99508
>>> N61° 11.710' W149° 46.723'
>>> www.data-plumber.com
>>>
>>>
>>> On 6/1/06, Bill Sheehan <[EMAIL PROTECTED]> wrote:
>>>>
>>>> That's the theory, which was borne out by MythBusters. In reality,
>>>> airline systems are shielded.
>>>>
>>>> If there really were a threat to airline safety from some twitnit
>>>> deciding to call home, they'd confiscate the bloody phones. Just
>>>> look at the paranoid precautions airline passengers must silently
>>>> suffer nowadays.
>>>>
>>>> -- Bill
>>>>
>>
>
>
> [Non-text portions of this message have been removed]
>
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