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Re: [Amps] placement of RF choke bypass cap.

To: <amps@contesting.com>
Subject: Re: [Amps] placement of RF choke bypass cap.
From: "DF3KV" <df3kv@t-online.de>
Date: Thu, 25 Mar 2010 01:46:25 +0100
List-post: <amps@contesting.com">mailto:amps@contesting.com>
OK, lets talk about a water tight chassis used for a GG amplifier.

The grid of the tube is screwed to the top of the chassis.
Under the chassis the driving signal is connected via a pi network to the
cathode.
How could the rf input signal develop a drive signal between grid and
cathode when there is no rf path to the grid through the chassis?

73
Peter


-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Gary Schafer
Sent: Mittwoch, 24. März 2010 22:24
To: dezrat1242@yahoo.com; amps@contesting.com
Subject: Re: [Amps] placement of RF choke bypass cap.



> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
> On Behalf Of Bill, W6WRT
> Sent: Wednesday, March 24, 2010 4:23 PM
> To: amps@contesting.com
> Subject: Re: [Amps] placement of RF choke bypass cap.
> 
> ORIGINAL MESSAGE:
> 
> On Wed, 24 Mar 2010 15:45:02 -0400, "Gary Schafer"
> <garyschafer@comcast.net> wrote:
> 
> >
> >Bill,
> >How many times do you want me to quote you saying that "skin effect
> does not
> >keep RF from flowing thru a plate"? it has been in almost every one of
> your
> >posts. That is what started this whole thread and continues it.
> 
> REPLY:
> 
> At this point I'm not sure what you are arguing about, Gary. I said
> that skin effect certainly exists but it does not prevent the
> simultaneous flow of electrons through a plate at 90 degrees to the
> skin current. Both events can happen at the same time, as was proven
> by the two gentlemen with the disk experiment. Skin effect current was
> flowing over the surface of the disk as a result of the disk's
> capacitance, and at the same time antenna current was flowing straight
> through the disk to reach the far end of the antenna or loop, WITHOUT
> having to flow around the radius of the disk in the form of skin
> current.
> 
> This is analogous to the chassis in the original discussion that was
> carrying skin current but was also passing RF through the thickness of
> the sheet metal. Both events are happening at the same time.
> 
> It's perfectly clear to me. Where are we mis-communicating?
> 
> 73, Bill W6WRT

It is analogous to nothing! One is an antenna and the other is a chassis
that we were talking about. Very different things going on there. And no,
the current still doesn't flow thru the antenna disks as you would like to
believe.

How is it that you say you believe skin effect exists and still insist that
RF current can flow thru a surface by some other means?

How about addressing the chassis rather than trying to divert the discussion
to something else.

Why do you think that w8JI's experiment shows that RF current doesn't pass
thru the sheet? 

Why do you think RF does not pass thru a screen room wall. You can connect
whatever you like to one side and it still will not pass thru to the other
side.

73
Gary  K4FMX

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