Just remember you get what you pay for. I bought a bag of these and
tested them per K0BG's procedure ( http://www.k0bg.com/beads.html )
using an MFJ-259B.
I don't know what mix they are but they are definitely not 43 or 31.
With five turns thru the bead I get a reactance of ~140 and an
inductance of 11 uH. If they were 43 they should have a reactance of
~500 and an inductance of ~40 uH.
I have tried this procedure on some other ferrite beads I have and I do
get the mix 43 values so K0BG's procedure does work.
I snapped some of these on the wires going to the fuel pump on my truck
and they made absolutely no difference in the noise. I took them off
and snapped on a couple of split beads I had from Radio Shack and the
noise dropped to almost nothing.
So, it seems questionable how effective these cheap ferrites beads are.
73,
Alan N5NA
Mac McDaniel wrote:
>Hi all,
>
>I have been reading the archives and found them very helpful.
>It was good to see some activity from the group today.
>
>I think that I have my problem figured out. With line isolators
>and RFI chokes. I wanted to share something that I found on
>eBay. I paid a lot of money for these RFI chokes at Radio Shack
>and other places. Check out this guy's prices!
>
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=296&item=5754435473&rd=1&ssPageName=WDVW
>
>I hope they help someone as much as they did me. You can't
>beat the price! I shared them with another group and they bought
>one of his auctions out. He must have a bunch because he keeps
>putting them back on another auction.
>
>73, Mac N0OB
>_______________________________________________
>RFI mailing list
>RFI@contesting.com
>http://lists.contesting.com/mailman/listinfo/rfi
>
>
>
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