Subject: Europa-List: Re: Ground/earth
From: "rampil" <ira.rampil@gmail.com>
Hi Ferg!
Sorry, but there is no Ground but The Ground in a composite aircraft!
That is to say, the negative side of the battery.
>From that it is simply a matter of practice in
minimizing the resistance back to that point. Noise is created when changing
current flows move across a resistance, and those changes in current occur
at high enough frequency to radiate to adjacent conductors.
Prevention of noise therefore seeks to minimize resistance to ground, and
improve shielding. Ira
Ira,
Quite right regarding the term "Ground" and its complications.
SO I added the UK 'earth', trying to show that it's not so simple when
radios are added. Radiating to adjacent conductors is OK provided they
aren't part of a radio installation. The purpose of the coax is to shield
such conductors from noise nearby. That can be accomplished only if the coax
is 'grounded' to the radio's prescribed point. Often, installations design a
circuit to forestall noise coming from the aircraft ground and so direct
coaxes to a radio ground, not the aircraft one. Old-style strobes can bang
out mighty peaks - and added to the audio noise.
What we need is another word for ground/earth and all I wanted
to do was suggest strict attention to installation instructions.
Cheers, Ferg
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