| Re: Mobile phone interference |
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Group: aus.aviation · Group Profile
Author: B J FosterB J Foster Date: Sep 20, 2008 00:29
Paul Saccani wrote:
> On Sat, 20 Sep 2008 13:28:52 +1000, B J Foster yahoo.com>
> wrote:
> >> David Lesher wrote:
>>> B J Foster yahoo.com> writes:
>>>>>>>> Yep, all sorts of nW1+/-mW2 stuff. And these days you can not assume that
>>>>> the circuit designer actualy knows the craft (i.e. the practical stuff).
>>>> Particular phone models could be quality accredited and permitted.
>>> As delivered, new; great. Now, who inspects them and tests leakage of
>>> each one a year later as you board with a very beat-up unit?
>>>
>>>> It is easy to shield the circuits with a metal box, or foil-wrapped plastic
>>> And how many phones come in metal boxes any more?
>>>
>>>
>> I had a V3 two years ago. Then it had a state-of-the-art metal case when
>> all the other phones were polycarbonate. In any case, the polycarbonate
>> phones have a foil lining inside the case. Same applies to laptops.
>
> Arrant nonsense.
"to achieve the extraordinary thinness of the MOTORAZRâ„¢ V3, we had
to use metal rather than plastic for the casing to provide the necessary
strength"
(Motorola company report, 2006)
"The radiation of electromagnetic energy is an important concern for the
designers of almost all electronic devices.
...
An otherwise clean device will violate the specs if even a single
frequency in the emission spectrum exceeds the radiation limit. Because
of their ubiquity and periodic nature, clock signals are usually a major
source of radiated energy.
Two EMI reduction methods are suppression (filtering) and containment
(shielding),..."
Source: Mobile handset design line
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