The device  being discussed, I think, is more properly called a 
split ferrite bead.  A toroid  is sort of a doughnut made of 
ferrite material or powdered iron and the cable or wire is wound 
through it several times.  There are ferrite beads that slip over 
a wire but they have to be put on before  plugs or connectors are 
installed.  The advantage of split beads, of course, is that they 
can be applied to a cord or cable and snapped together like the 
Radio Shack item, or the two halves are sometimes held together 
with tape.

Unless they come in different sizes, the split beads I got from 
Radio Shack would not fit a heavy air conditioner cord.  However, 
there are large split ferrite beads that can fit RG8-sized cable 
available from such places as Amidon Associates, The Wireman and 
Ppalomar Engineers.

Amidon, Inc.
240 Briggs Avenue
Costa Mesa, CA 92626
1-800-898-1883
Fax (714) 850-1163
www.amidoncorp.comwww.thewireman.com

Palomar Engineers
P.O. Box 462222
Escondido, CA 92046
(760) 747-3343
FAX: (760) 747-3346
http://www.palomar-engineers.com
E-mail: [log in to unmask]

The wireMan
261 Pittman Road
Landrum, SC 29356
Orders only: (800) 727-9473
Tech Help: (864)895-4195
http://www.thewireman.com


73.

Mike, K9AZS
> ----- Original Message -----
>From: Ed Malmgren <[log in to unmask]
>To: [log in to unmask]
>Date: Fri, 2 Jun 2006 09:39:36 -0600
>Subject: Re: rfi question

>Tom, the last ones that I have gotten were different, they open 
up from the
>side and you have two half's of the magnet.  They are more 
convenient to use
>than the ones your talking about.  Ed K7UC