[time-nuts] Noise and non-linear behaviour of ferrite

Kit Scally kitscally at iprimus.com.au
Sun Jul 20 01:43:36 EDT 2014


>From my (past) CATV experience, ferrite-based devices don't introduce
"noise" as such but they can certainly pick up noise (or transmit) unless
they are toroidal or otherwise well screened.
However, they can introduce distortion if the winding flux density
approaches the ferrite's saturation level.  In the CATV world where
amplifier launch-levels approach +40 to 50 dBmV, close-by "splitters" being
fed this level produce not-so-subtle IM and distortion artefacts.  Drop the
level "3dB" and it all disappears.


Message: 3
Date: Sun, 20 Jul 2014 00:09:00 +0200
From: Attila Kinali <attila at kinali.ch>
To: time-nuts at febo.com
Subject: [time-nuts] Noise and non-linear behaviour of ferrite
Message-ID: <20140720000900.f23007cffc95862dfbb9e86c at kinali.ch>
Content-Type: text/plain; charset=US-ASCII


I'm currently looking at some way of breaking the ground loop between
several systems. The obvious idea would be to use transformers. I would like
to have some kind of rule of thumb to guess how much noise such a
transformer would add. But unfortunately i cannot find any theory or
measurements of this. Does anyone have some pointers to documents on what
kind of noise i could expect (type, and strength) and what/how strong the
non-linear behaviour of transformers would be?

Thanks in advance

			Attila Kinali

PS: although this started as something with a real application in mind, i'm
now interested in this as an endavour of its own. So all and any data,
theory or rule of thumb would be appreciated

I pity people who can't find laughter or at least some bit of amusement in
the little doings of the day. I believe I could find something ridiculous
even in the saddest moment, if necessary. It has nothing to do with being
superficial. It's a matter of joy in life.
			-- Sophie Scholl

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