Tom is confusing Faraday shield with Electrostatic shield and whole reasoning
that the grounded shield of small loop antenna is THE antenna is all wrong.
Wire loops inside the electrostatic shield are perfectly OK to receive the RF
and ARE the antenna. Electrostatic shield in small loop antennas reduces the
interference, electrical noise locally generated (prevalent electrical fields).
Faraday shield is the cage, cube, tube of conductive material that is
completely enclosed and prevents RF from penetration to the inside of the
enclosure. Electrostatic shield has a slot, opening and prevents, attenuates
electrical fields by virtue of its capacitance to the surroundings. Locally
generated electrical noise, signals withing half wave or so are electrical
fields in nature and are attenuated by the electrostatic shields, such as in
properly designed small loop antennas.
I have built bunch of them, verified their performance and saw the effect.
Interesting combination was using small loop in the proximity of Beverage, but
that is another story.
73
Yuri Blanarovich, K3BU
----- Original Message -----
From: Donald Chester <k4kyv@hotmail.com>
Date: Sunday, May 14, 2006 5:39 pm
Subject: Re: Topband: QST Jun 06 RX Loop
>
> >From: "Tom Rauch" <w8ji@contesting.com>
>
> >...It is a very well known physical property of a "shield" more
> >than several skin depths thick that essentially nothing goes
> >through that shield. It's a Faraday cage, and when the
> >time-varying electric field goes to zero so does the
> >magnetic field.
>
>
> Tom:
>
> One question that some readers of this forum might ask: If that
> is the
> case, how does an inductively coupled network, where two resonant
> inductors
> are separated by a Faraday shield, transfer energy?
>
That is another example of the Electrostatic shield. Also used in AC and audio
transformers.
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