OT: Big Ferrite Split Beads @ B.G. Micro

[Jim Sheldon]

Anyone needing those big ferrite, snap together, split beads for reducing RFI on cables,   B.G. Micro has them in stock at a pretty good price.  $1.43 each plus shipping.

Jim - W0EB

http://www.bgmicro.com/COL1066.aspx
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[ab2tc]

Any idea what the ferrite material is?

AB2TC - Knut

Jim Sheldon-2 wrote

Anyone needing those big ferrite, snap together, split beads for reducing RFI on cables,   B.G. Micro has them in stock at a pretty good price.  $1.43 each plus shipping.

Jim - W0EB
<snip>

[Jim Sheldon]

They didn't list the material type in the ad, so no, I don't.  I suspect they are surplus from a computer power supply manufacturer as they are about the same size as those used around the output leads of many of the switching supplies used in computers.

I've had several queries on this so I'm posting here - I have no idea what ferrite material is used in these cores and by the time the ones I ordered get here and I test them with my antenna analyzer and a 5 turn loop, they'll probably be sold out.  

Jim - W0EB

>
> Any idea what the ferrite material is?
>
> AB2TC - Knut
>
>
> Jim Sheldon-2 wrote:
>
>> Anyone needing those big ferrite, snap together, split beads for
>> reducing
>> RFI on cables,   B.G. Micro has them in stock at a pretty good
>> price.
>> $1.43 each plus shipping.
>>
>> Jim - W0EB
>> <snip>

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[ab2tc]

For the record, Mouser has a similar snap-on ferrite in the preferred (for HF) #31 material here:

http://www.mouser.com/ProductDetail/Fair-Rite/0431167281/?qs=KmHvPbTOE4S79xB57hcPyQ%3d%3d

The part number is 623-0431167281. The hole is about 0.4". A smaller version is this part# 623-0431164281

These are not terrible expensive either and can be bought in any small quantities. I used 4 of them to bring down the noise on the Ethernet cable from my Dell computer. Dell seems to be particularly bad for common mode noise from the Ethernet port. The router and my GB switch also in the shack are fine.

AB2TC - Knut

Jim Sheldon-2 wrote

They didn't list the material type in the ad, so no, I don't.  I suspect they are surplus from a computer power supply manufacturer as they are about the same size as those used around the output leads of many of the switching supplies used in computers.

I've had several queries on this so I'm posting here - I have no idea what ferrite material is used in these cores and by the time the ones I ordered get here and I test them with my antenna analyzer and a 5 turn loop, they'll probably be sold out.  

Jim - W0EB

<snip>

[ab2tc]

Here is another useful link:

http://www.mouser.com/catalog/catalogUSD/642/952.pdf

[Leigh L. Klotz Jr WA5ZNU]

ab2tc wrote

I used 4 of them to bring down the noise on the Ethernet cable from my Dell computer.

Did you use 4 in series or 4 on different cables?

Leigh/WA5ZNU

[ab2tc]

[ab2tc]

In series on one cable. It took that many to bring the spurs (fairly clean carriers every 61kHz, peaking in the 15m band) down to the antenna noise level on that band.

AB2TC - Knut

Leigh L. Klotz Jr WA5ZNU wrote

ab2tc wrote

I used 4 of them to bring down the noise on the Ethernet cable from my Dell computer.

Did you use 4 in series or 4 on different cables?

Leigh/WA5ZNU

[Russ Tobolic]

The ad says "44 & 43 materiel".  Going by the P/N it looks like #43 ferrite.

Russ,
N3CO

----- Original Message -----
From: "Jim Sheldon" <[hidden email]>
To: "ab2tc" <[hidden email]>; <[hidden email]>
Sent: Wednesday, January 19, 2011 11:21 AM
Subject: Re: [Elecraft] OT: Big Ferrite Split Beads @ B.G. Micro

> They didn't list the material type in the ad, so no, I don't.  I suspect
> they are surplus from a computer power supply manufacturer as they are
> about the same size as those used around the output leads of many of the
> switching supplies used in computers.
>
> I've had several queries on this so I'm posting here - I have no idea what
> ferrite material is used in these cores and by the time the ones I ordered
> get here and I test them with my antenna analyzer and a 5 turn loop,
> they'll probably be sold out.
>
> Jim - W0EB
>
>>
>> Any idea what the ferrite material is?
>>
>> AB2TC - Knut
>>
>>
>> Jim Sheldon-2 wrote:
>>
>>> Anyone needing those big ferrite, snap together, split beads for
>>> reducing
>>> RFI on cables,   B.G. Micro has them in stock at a pretty good
>>> price.
>>> $1.43 each plus shipping.
>>>
>>> Jim - W0EB
>>> <snip>
> ______________________________________________________________
> Elecraft mailing list
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html 

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[Guy, K2AV]

>From a link earlier in the thread, Mouser sells the Fair-Rite #31 material
snapons and has them in stock:

623-0431164181 0431164181 B 100 156 260 - - - - - - 1.220 0.512 1.550 0.600
3.64 3.60 2.87
623-0431164281 0431164281 B 113 188 310 - - - - - - 0.788 0.260 1.550 0.385
2.13 1.81 1.48
623-0431164951 0431164951 B 100 169 280 - - - - - - 0.680 0.200 1.420 0.331
1.64 1.37 1.33
623-0431167281 0431167281 B 81 144 240 - - - - - - 0.933 0.400 1.550 0.460
2.64 2.33 1.80
623-0431173951 0431173951 B 60 100 180 - - - - - - 0.504 0.200 0.984 0.220
1.27 1.19 .909
623-0431176451 0431176451 B 130 225 380 - - - - - - 1.520 0.722 1.870 0.754
6.99 6.30 6.17
623-0431177081 0431177081 B 145 235 375 - - - - - - 2.220 1.000 1.690 1.080
16.41 12.62 11.47

The second figure in the right side numbers is the diameter of the hole when
the snapon is closed.  Have a look at K9YC's excellent web page on the
characteristics for the ferrite type.  #31 is what you want to use for
suppression purposes 160-30 meters.

http://www.mouser.com/catalog/catalogUSD/642/952.pdf

I have ordered some 623-0431176451 because I want to put 5 or 6 turns of
cat5 through them to mitigate some problems with AT&T Uverse, whose VDSL
uses 1-12 MHz baseband.  These should put over 1000 ohms of resistive
suppression at 160m.  Suppression is hard to come by on 160 and #31 is
superior to the rest.  The Fair-rite catalog contains measured suppression
resistance at 1 and 5 MHz.  These numbers are not in the Mouser catalog.

On Thu, Jan 20, 2011 at 12:17 PM, Russ <[hidden email]> wrote:

> The ad says "44 & 43 materiel".  Going by the P/N it looks like #43
> ferrite.
>
> Russ,
> N3CO
>
> ----- Original Message -----
> From: "Jim Sheldon" <[hidden email]>
> To: "ab2tc" <[hidden email]>; <[hidden email]>
> Sent: Wednesday, January 19, 2011 11:21 AM
> Subject: Re: [Elecraft] OT: Big Ferrite Split Beads @ B.G. Micro
>
>
> > They didn't list the material type in the ad, so no, I don't.  I suspect
> > they are surplus from a computer power supply manufacturer as they are
> > about the same size as those used around the output leads of many of the
> > switching supplies used in computers.
> >
> > I've had several queries on this so I'm posting here - I have no idea
> what
> > ferrite material is used in these cores and by the time the ones I
> ordered
> > get here and I test them with my antenna analyzer and a 5 turn loop,
> > they'll probably be sold out.
> >
> > Jim - W0EB
> >
> >>
> >> Any idea what the ferrite material is?
> >>
> >> AB2TC - Knut
> >>
> >>
> >> Jim Sheldon-2 wrote:
> >>
> >>> Anyone needing those big ferrite, snap together, split beads for
> >>> reducing
> >>> RFI on cables,   B.G. Micro has them in stock at a pretty good
> >>> price.
> >>> $1.43 each plus shipping.
> >>>
> >>> Jim - W0EB
> >>> <snip>
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>

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[Craig Smith]

I'd like to follow up on K2AV's excellent recent post.

Thanks to K9AY's previous work, I also was turned on to the type 31 material
for RF suppression at HF.  I have found it to be substantially better than
type 43, especially on the lower bands and for broadband use.

A hint for those of you who are contemplating placing an order for some of
the clamp-ons:  The smaller diameter clamp-ons look attractive at first
glance due to their low prices and ability to fit most of the small cables
in your shack.  But remember the choking impedance goes with the square of
the number of turns.  A more expensive core with a larger aperture will be a
much better bang-for-the-buck.  For example, a core that allows 3 turns of a
given cable will be 9 times more effective than a single turn core and might
only cost only 50% more.  Needing to use several single turn cores adds up
quickly cost-wise.

I use lots of the 0431164181 clamp-ons here.  They will accommodate one pass
of RG-8 size coax or several turns of computer cables, audio cables, etc.
For example, it will allow 6 or 7 turns of RG-174.

73  Craig  AC0DS





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[Jim Brown-10]

On 1/19/2011 8:21 AM, Jim Sheldon wrote:
> I've had several queries on this so I'm posting here - I have no idea what ferrite material is

It makes no sense to buy unknown ferrite cores, especially for use on
the HF bands. Study my tutorial on RFI to understand why.

http://audiosystemsgroup.com/RFI-Ham.pdf

73, Jim Brown K9YC
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[Jim Brown-10]

On 1/20/2011 11:34 AM, Craig D. Smith wrote:
> A hint for those of you who are contemplating placing an order for some of
> the clamp-ons:  The smaller diameter clamp-ons look attractive at first
> glance due to their low prices and ability to fit most of the small cables
> in your shack.  But remember the choking impedance goes with the square of
> the number of turns.  A more expensive core with a larger aperture will be a
> much better bang-for-the-buck.  For example, a core that allows 3 turns of a
> given cable will be 9 times more effective than a single turn core and might
> only cost only 50% more.  Needing to use several single turn cores adds up
> quickly cost-wise.

Good advice. -- but there's more. RFI suppression comes from a high
resistive impedance, which in turn occurs around the resonance of the
choke. A single pass through a typical #31 or #43 core is resonant
around 200 MHz -- USELESS on HF.  Multiple turns moves the resonance of
the choke lower in frequency where we need it.   My RFI tutorial
includes graphs of MEASURED data for some useful cores, and it also
includes a list of ferrite cores that are most useful on the HF and VHF
bands.  See Appendix One.   See my previous post in this thread for a
link to the tutorial.

> I use lots of the 0431164181 clamp-ons here.

Yes,something this size is quite useful for quieting down noisy computer
and audio gear.

73, Jim Brown K9YC

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[ab2tc]

Hi all,

I followed the advice about the advantage of the larger cores and ordered a few those and a few of these: 0431176451. They came in today and the latter ones are *huge* and heavy; I was shocked when I open the parcel from UPS (Mouser sure packs them well). But hopefully they will come in handy as long as there is something solid to support their weight. Not something you can have hanging off your router or switch.

AB2TC - Knut

Craig D. Smith wrote

<snip>
I use lots of the 0431164181 clamp-ons here.  They will accommodate one pass
of RG-8 size coax or several turns of computer cables, audio cables, etc.
For example, it will allow 6 or 7 turns of RG-174.

73  Craig  AC0DS

<snip again>