RFI
[Top] [All Lists]

Re: [RFI] Ferrite bead disintegration

To: Ken Winterling <wa2lbi@frontiernet.net>
Subject: Re: [RFI] Ferrite bead disintegration
From: Pete Smith <n4zr@contesting.com>
Reply-to: n4zr@contesting.com
Date: Mon, 23 Aug 2010 10:12:27 -0400
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
They were lying in the grass, largely during the winter months, under no 
physical stress at all, unless sun heat might have been a factor due to 
the use of black vinyl electrical tape to wrap the beads after they were 
put on the RG-59.  But this is another reason to be worried about the 
bead chokes at my array feedpoints, because they are up year-round, 
subjected to whatever stresses are imposed by the wind, weight of the 
coax, etc.

73, Pete N4ZR

The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at 
reversebeacon.blogspot.com,
spots at telnet.reversebeacon.net, port 7000


On 8/23/2010 9:29 AM, Ken Winterling wrote:
> Pete,
>
> I have seen mechanical stress do this.  You didn't indicate the 
> physical construction technique used to build the choke but it is 
> possible that movement of the beads against one another caused them to 
> crack.
>
> Ken, WA2LBI
>
>
> On Mon, Aug 23, 2010 at 09:10, Pete Smith <n4zr@contesting.com 
> <mailto:n4zr@contesting.com>> wrote:
>
>     I took apart a home-made 100 bead receiving-only common mode choke
>     yesterday.  As I peeled off the electrical tape I was surprised when
>     each bead that came out of the wrapping disintegrated into dozens of
>     fragments.  I think I saved about 5 beads out of a 100-bead choke.
>
>     What could have caused this?  The choke was used over 300 feet
>     away from
>     my transmit antennas, and never used for transmitting.  Morte to the
>     point, can I expect to see the same thing in the feedpoint chokes
>     of my
>     80m 4-dipole lazy vee array, which have been up and in use for ~10
>     years?
>
>     --
>     73, Pete N4ZR
>
>
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi

<Prev in Thread] Current Thread [Next in Thread>