[RFI] Inexpensive sources of 31 mix Ferrite

N6KI Dennis Vernacchia n6ki_73 at sbcglobal.net
Sun Feb 18 15:31:22 EST 2007

Thought this may be of interest to those reading the recent
threads on 31 mix ferrite

I have no pecuniary interest in the matter

73, Dennis N6KI


  I was in the process of making a group buy for our local radio club
of some -31 Mix Ferrite clamp on beads
that will fit tightly on RG-213 size coax and also be good for smaller 
cables that I could
thread thru several times for efficacy. ( Hole is approx 0.400" )

    I discovered that Mouser Electronics now sells at least this one 
particular -31 Mix Ferrite
bead that works well for RFI problems per Jim Brown's recommendations in 
the past
on this reflector. ( These do well in place of 43 or 77 mix and I now 
use this
mix from 160 thru 6 mtr band to resolve RFI probs with good results )

    They are $2.70 in small quantity but drop to $1.70 for 100 pieces, 
so get together with
a few buddies or your local contest or DX club and snap up the discount !

You can get to Mouser's order page by typing


in Google search and it will be the first hit you get

or go to www.mouser.com and enter part number  623-0431167281

Part # 	Mfr.'s
Part # 	Manufacturer
Your Part# 	Order
Qty. 	Availability* 	Price 	Ext.
  	623-0431167281 	0431167281

*NOTE: Important !*
I found one anomaly with these and that is that if you do use them to 
snap directly onto
RG-213 type coax ( approx 0.400" Diameter) or coax with the same 
diameter, the plastic shell that comes
with the bead has a slightly* smaller *diameter than the hole in the 
ferrite bead itself and will not allow
you to clamp the bead onto the coax until you take a pair of diagonal 
cutters and trim the
plastic making the hole bigger. Just a nuisance for now as I have 
alerted Mouser  and Fair-rite
and hopefully they will use the correct plastic shell in the future.

    Also, if you would like to buy 2.4" Round ( Donut ) type, ( 
Fair-Rite P/N *2631803802  )
*and these are really great for really tough RFI problems, you can order 
them from Dexter Magnetic Technologies   
     I am not sure what their minimum order is but when I do my group 
buys of 100 pieces
I have gotten a piece cost down near $3, though I hear the price will be 
rising sharply soon
due to the price of one of the materials use in making the -31 MIX - ( 
like going to $4.28 ea in 100 Qty ! )

DEXTER MAGNETIC TECHNOLOGIES <http://www.dextermag.com>

or go to www.fair-rite.com

click on PRODUCTS ( First Pull Down Tab)
Then enter the part number *2631803802 ( 2.4 inch Donut -31 Mix )

*and something like this info below will come up shopping who has stock.

2631803802 	160 	11/26/2006 	Amidon Inductive Components 
<http://www.amidoncorp.com> 	800/898-1883

2631803802 	305 	11/24/2006 	Kreger Components, Inc 
<http://www.kregercomponents.com> 	800/609-8186

2631803802 	211 	11/20/2006 	DEXTER MAGNETIC TECHNOLOGIES 
<http://www.dextermag.com> 	800/775-3829

73, Dennis Vernacchia N6KI
San Diego

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