Tony,
I assume water got into the pores or onto the surface of the cores and cracked
when the water froze.
I always enclose my cores, as well as my connectors and protective devices
(transzorbs), in an enclosure such as a NEMA box. I run my connections into the
box from the bottom or from the side with the cable facing downwards so that
water does not run into the enclosure. I cover the side cables with
electricians putty to further keep out water. I have put sccreening over the
went holes on the bottom to keep out insects.
Mike N2MS
> On June 19, 2017 at 8:03 AM "N2TK, Tony" <tony.kaz@verizon.net> wrote:
>
>
> The cores that came apart were not snap-ons. They were solid cores.
> N2TK, Tony
>
> -----Original Message-----
> From: Charles Coldwell [mailto:coldwell@gmail.com]
> Sent: Monday, June 19, 2017 7:44 AM
> To: N2TK, Tony <tony.kaz@verizon.net>
> Cc: RFI RFI <rfi@contesting.com>
> Subject: Re: [RFI] Snap-on Ferrites
>
> Could this have something to do with the unavoidable gap in the
> high-permeability material in a snap-on ferrite? The majority of the MMF is
> usually in the air gap.
>
> On Mon, Jun 19, 2017 at 6:47 AM, N2TK, Tony <tony.kaz@verizon.net> wrote:
> > Here in upstate NY I have Fair-Rite FT-240 #31 cores on my RG6 receive
> > antennas - 8 turns. This spring when I did an inspection I saw that
> > several cores had split or had chunks out of them. Do the cores need
> > to be protected from the weather? I replaced the broken cores with the
> > biggest clamp-on, #0431177081, #31 ferrite with 8 turns. They are just
> > lying on the ground.
> > Should I enclose them?
> >
> > I made up four 3/4 wave length RG6 lines for my 80M 4-square. I used
> > the same biggest clamp-on ferrite with 8 turns at the feedpoint.
> > Should I do anything additional such as tie wrap them and/or enclose the
> > ferrite?
> >
> > 73,
> > N2TK, Tony
> >
> > -----Original Message-----
> > From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of Ed K0iL
> > Sent: Sunday, June 18, 2017 11:20 PM
> > To: john@kk9a.com; rfi@contesting.com
> > Subject: Re: [RFI] Snap-on Ferrites
> >
> > John,
> >
> > Seems we can always get more turns around a toroid ferrite (several)
> > than you can on a snap on ferrite (maybe one). This would make
> > snap-ons less effective than a toroid core based on number of turns.
> >
> > 73, de ed -K0iL
> >
> > -----Original Message-----
> > From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of
> > john@kk9a.com
> > Sent: Sunday, June 18, 2017 9:44 PM
> > To: towertalk@contesting.com; rfi@contesting.com
> > Subject: [RFI] Snap-on Ferrites
> >
> > I was reading the recent QST article RF Mayhem by WB8IMY. The author
> > said to avoid using snap-on ferrites for problems caused by HF signals
> > as they rarely work well at HF. It is best to stick with circular cores.
> >
> > Is this correct? I was not aware that snap-ons were less effective.
> >
> > John KK9A
> >
> > _______________________________________________
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> > RFI@contesting.com
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> >
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>
>
>
> --
> Charles M. Coldwell, W1CMC
> Belmont, Massachusetts, New England
> "Turn on, log in, tune out"
>
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