[RFI] Refrigerator RFI

[Alan Higbie]

Hi Jim McCook 'YA

My refrigerator RFI story . . .

I had what sounded like broadband white noise. Noticed it on 80 meters
(during the day while band was closed).

Shut off power to my house, and the white noise disappeared. The source was
something in our house.

Then turned power back on.  Used an SDR receiver - and zoomed way in until
looking at a total span of only 1.5 kHz.

Now, zoomed in, and could see spikes every 50 cycles or so.

This was not "white noise" as from an atmospheric source

Using an SDR receiver, I sniffed around with small loop located source --
our refrigerator.  The fridge is approximately 75 feet from my 80 meter
antenna (with common mode choke at feed point).

Kenwood Elite Model 795.71049.010.  From Sears (is that still a thing?)

*REMEDY*: Wrapped the refrigerator's power cord several times through one
large #31 snap-on ferrite.
That reduced RFI quite a bit.  But did not completely eliminate it.

So I placed a second snap-on along the power cord.  With two big snap-on
ferrites the RFI was completely eliminated.

73, ~ Alan K0AV



On Thu, Sep 7, 2023 at 7:37 PM Dave (NK7Z) <dave at nk7z.net> wrote:

> I took a portable SW receiver to the showroom when we bought our new
> fridge and listened, and got the most RF quiet one my wife liked...
>
> I also told them, I wanted THAT refer, not a different one when I bought
> it.
>
> 73, and thanks,
> Dave (NK7Z)
> https://www.nk7z.net
> ARRL Volunteer Examiner
> ARRL Technical Specialist, RFI
> ARRL Asst. Director, NW Division, Technical Resources
>
> On 9/7/23 17:04, Jim McCook wrote:
> > Help!  We suddenly need a new refrigerator, so am looking to find out
> > which ones are RFI generators and which ones are established as clean.
> > Any input?   73, Jim W6YA
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> > RFI at contesting.com
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