[TenTec] Induction Field [WAS - PS grounding]

[Ken Brown]

David McClafferty wrote:

>To induce a current into a conductor the magnetic
>field must be varying or the conductor or field must
>be moving. The magnetism in an MRI machine is steady,
>so unless they wheeled you in there quite fast, you
>wouldn't get much current induced into your body.
>  
>
Excuse me, but if there is no change in the field, it will not make 
anything resonate. I'll look at the url you included later and see what 
they say. If they say that it is a constant, non varying magnetic field, 
then I say they are wrong. I took my VX-5 handheld radio and listened 
outside the lab while my wife was in the MRI machine. And I heard lots 
of varying  pulse rates and bandwidth signals around the 60 MHz area. 
What I heard defininately came from the MRI machine, and it is not 
surprising that water molecules have a resonance around 60 MHz, human 
bodys being mostly water. Also the spare 3CX800A7s that I have for my 
Titan 425 are pulls from a MRI machine. If it was a constant magnetic 
field and not a varying one (at RF frequencies where ther are resonances 
with things in the body) they could just use a switch of some sort and 
not need a power amplifier tube>