Date: Sun, 04 Feb 2007 12:22:49 -0500
From: Finn Lassen <finn.lassen@verizon.net>
Subject: Re: [FlyRotary] Re: wire routing
In-reply-to: <list-1809967@logan.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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Alu will shield RF emissions just fine.
Don't know of any Alu that will shield a magnetic field.

Mu-metal (whatever that is) /will/ shield a magnetic field. Found around 
the "picture" tube in (presumably now old) oscilloscopes.

Finn

Lehanover@aol.com wrote:
> In a message dated 2/3/2007 11:56:08 P.M. Eastern Standard Time, 
> jwvoto@itlnet.net writes:
>
>     Am I wrong, I believe that aluminum will not shield magnetic flux,
>     giving only electrostatic shielding; only steel will shield
>     magnetic flux.
>      
>     Wendell
>
> Notice that your IF cans have aluminum all around?  Never seen an IF can?
>  
> In the olden days radios had big vacuum tubes, and open core 
> capacitors to adjust tank circuits and control frequencies. The 
> Inter-frequency  transformers had to be shielded to control phasing 
> and awful noise in the output. Thus the aluminum can shielding. Good 
> for wave guides as well.
>  
> Ferris metals concentrate flux fields (conduct flux lines well) and 
> are used in the cores of transformers and solenoids.  
>  
> Lynn E. Hanover