From my experience, I've had about 15 2.4" toroids hanging at the
antennas, unprotected for about 5 to 10 years with out a chip. I either
super glue, or epoxy the cores together. An example:
http://www.rogerhalstead.com/ham_files/AntennaFeed2.htm
73, Roger (K8RI)
On 6/19/2017 Monday 8:03 AM, N2TK, Tony 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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--
Charles M. Coldwell, W1CMC
Belmont, Massachusetts, New England
"Turn on, log in, tune out"
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