[Amps] placement of RF choke bypass cap.

[Gary Schafer]

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
> On Behalf Of Bill, W6WRT
> Sent: Thursday, March 18, 2010 2:29 PM
> To: amps at contesting.com
> Subject: Re: [Amps] placement of RF choke bypass cap.
> 
> ORIGINAL MESSAGE:
> 
> On Thu, 18 Mar 2010 13:15:03 -0400, "Gary Schafer"
> <garyschafer at comcast.net> wrote:
> 
> >
> >Not directly thru the chassis.
> >Hear is a little example:
> >
> >http://www.w8ji.com/skindepth.htm
> >
> >73
> >Gary  K4FMX
> 
> REPLY:
> 
> Ok, it seems my padding capacitors are not connected. I wonder how I
> am able to tune up on 160 meters?
> 
> Seriously though, W8JI is injecting a signal on only one side of the
> sheet, using one side of the sheet as part of a loop. This is
> different from using the whole thickness of the sheet as a conductor,
> which is what the original discussion was about, and what is happening
> in my example above.
> 
> I have to admit, W8JI's experiment is fascinating even if not exactly
> relevant.
> 
> 73, Bill W6WRT

But it is relevant. It is the same thing. He has part of one surface
conducting RF between the two terminals. Measuring on the other side of the
sheet shows no current on the other side. 
If you think about it the sheet of copper or your chassis, as far as RF is
concerned, is two very thin sheets with an insulator in the middle. The
insulator comes about because of skin effect.

It is no different than the shield on a coax cable. No RF energy can
penetrate the shield because of skin effect. 

73
Gary K4FMX