Re: Faraday Cage

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Dave,

At 10:25 PM 12/17/2002 -0500, you wrote:
>>If you want a frustrating experiment with a Faraday cage,
>>exactly in frequencies close to microwaves, put a cell
>>phone inside a microwave oven, close the door, and call
>>it.
>
>         Different freqs.  and cell phones are exquisitely
>         sensitive, to keep Tx power requirements down.

Incredibly(!),  If you put some of the new fancy cell phones inside a 
little (10 inch dia.) solid copper shell and call them with the transmitter 
reasonably near, those darn little devilish things still ring!!  The 
transmit sections can pull ring signals right out of the either noise at 
like -140dB down!!!

Just the signals hitting the copper and causing 'little' eddy currents, 
allows enough to leak inside to the phone's hypersensitive circuits...

I fun trick at sites that have like fancy TUV RF shielded chambers is have 
someone call you while inside the supposed dead quite' RF chamber ;-))


>>(Of course don't turn the oven on!)

Personally, I prefer to turn the oven on to rid my self of the little cell 
phone devils ;-)))

>>I wonder if the oven keeps its own radiation inside...

"Enough" of it ;-))

On a more serious note...

I think even a "poor" cage would do wonders in keeping the "E" fields 
down.  But the "B" (magnetic fields) off that high current primary will go 
right through a cage and that may be what a pacemaker is most sensitive to 
anyway.  A person's body will attenuated E-fields pretty fast (non-contact) 
but high magnetic fields induced on a pacemaker's lead and all may not be 
good.  Pacemakers are actually pretty good at defending themselves against 
stray fields (like direct contact defibrillators) but amateur experimenting 
is pretty rough here!!

There actually have been a few coilers that have "mentioned" they could do 
pacemaker tests (they had access to the bare machines) but we have never 
heard back as to any results :-(

Ebay does not have any pacemakers listed so we just can't just "buy one one 
see"...  Pacemakers have a lot of "details" depending on the situation so 
there are no "fit all" recommendations...  Too many and, if, ors, and buts 
on this subject....

Cheers,

         Terry


>         best
>         dwp