Re: Way of topic--ferrite cores

David Cutter

If you are running appreciable power compared to the size of the choke, then exposed to the elements aids cooling, particularly in RTTY and AM.  See Jim Brown's amazing research on chokes.

David G3UNA


From: [] On Behalf Of Chris Moulding
Sent: 14 August 2018 16:51
Subject: Re: [CrossCountryWireless] Way of topic--ferrite cores


I've left a few open ferrite baluns out exposed to the elements for a year or two.*

On inspection there was a fine white powder on the ferrite probably caused by corrosion with exposure to rain water. The properties of the ferrite were unchanged so it doesn't look like water soaks in, just corrodes the metal exposed on the surface.

*By the way it's the perfect example of the old saying "The cobbler's son is always worst shod". We make baluns housed in watertight polycarbonate enclosures with stainless steel fittings. I get to use the unboxed prototypes if I'm lucky!



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