[RFI] 3" ID core for RFI suppression

[Joseph Bouchard]

Howard,
If it were me, and I have a bunch of 240-31’s, I would make a short extension cord with the cores I have.  I’d start with 1, go to 2 if necessary.  If you have to order something, you might as well get the 3” one.  Look around, there may be places cheaper then Palomar.

Good luck,
Joe K1VW

> On Dec 29, 2020, at 8:07 PM, Howard Lester <howard220 at gmail.com> wrote:
> 
> Very long story short: A particular circuit card (I am guessing so) of my 2-1/2 year-old Maytag HE washing machine is susceptible to RFI from… my propane-fueled furnace! The symptom is occasional: A loud 2-step snapping sound that emanates from parts of the back of the machine’s control panel when the furnace first gets the signal from the thermostat, and then begins its cycling on. It happens just once in a while, and I can prevent it from happening at all simply by unplugging the washer from the AC outlet. What could be easier? 
> 
> When the snapping recently occurred when my 16KW Generac generator kicked on for its weekly 5-minute exercising, I got even more suspicious. And when yesterday I transmitted with 75 watts on 20 m SSB, using my MFJ Hi-Q Loop up in the attic about 15-20 feet away from the washer, and I heard the snapping multiple times, I then said, “This means war!”  ;-) (That was the first time I ever heard the washer do that from me transmitting on any band. I rarely use more than 50 watts.)
> 
> The flat AC cord is a bit under 1/2” across and has a large plug. The plug size requires about a 2” I.D. core, but I cannot find anything specifically of Type 31 or 77 or, really, anything — except this:
> 
> https://palomar-engineers.com/ferrite-products/AC-Cable-Noise-Filter-for-Large-Plugs-3-ID-p75172171 <https://palomar-engineers.com/ferrite-products/AC-Cable-Noise-Filter-for-Large-Plugs-3-ID-p75172171>
> 
> But it’s $40+, and I don’t want to spend that kind of money if it’s not the right tool for the job. No, I will not cut the AC cord. The washer is past its 1 year full parts and labor warranty, so I’m out of luck there. (Until last November, well past the 1 year, I thought all along it was the furnace making the snapping sounds.)
> 
> Thanks for any ideas. No, I’m not going to replace the washer. As I said, I can just unplug the thing except for the few times a week I use it. 
> 
> Howard N7SO
> 
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