Washing Machine RFI -- A Tidal Wave?

My wife and I have a Whirlpool Duet washer and dryer. The RF noise that the washer makes is terrible. I used my Elecraft KX1 and a clip lead antenna for finding where the noise was strongest. It all comes from the front control panel, which is plastic. Little comes from the power cord. I also found tremendous noise used on AM and FM broadcast radios in the house.

I posted a message to an RFI mailing list, and found a few other people with similar problems, using Gibson and Maytag Neptune brands.

The Gibson washer was quieted by an AC line filter, but nothing has helped the Whirlpool Duet or Maytag Neptune. It appears that the noise comes from the control panel and the variable-frequency AC motor circuits.

I asked Whirlpool for their Part 15 certification, and found out by reading the regulations that they don't have to have a certification number for computer and control circuits in appliances.

While these front-loading, computer-controlled washing machines are on the higher end of the price range right now, it is my belief that this new generation of washers is going to produce noise on a tremendous scale as consumers begin to demand them and prices come down. I believe that the manufacturers are exploiting a loophole in Part 15, and one that isn't even mentioned in the ARRL's Part 15 page. See Part 15.103, "Exempted Devices":

Sec. 15.103 Exempted devices.

The following devices are subject only to the general conditions of operation in Sec. Sec. 15.5 and 15.29 and are exempt from the specific technical standards and other requirements contained in this part. The operator of the exempted device shall be required to stop operating the device upon a finding by the Commission or its representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected. Although not mandatory, it is strongly recommended that the manufacturer of an exempted device endeavor to have the device meet the specific technical standards in this part.

(d) A digital device utilized exclusively in an appliance, e.g., microwave oven, dishwasher, clothes dryer, air conditioner (central or window), etc.

So, in summary, I believe that we are headed for an onslaught of RFI from washing machines.


Here are the details for my Whirlpool Duet.

Whirlpool has sent me a new motor and control unit to install and see if the problem is particular to my unit, but they said there were no hardware changes in the parts at all. Unfortunately I've been unable to this because the washer is now in storage during construction work, and I'm trying to decide whether to get a new washer.

Spectrum Images

The images below are waterfall images from my PSK program connected to two different receivers. Note that the band starts out quiet, with weak PSK signals present, and then gets a broad noise, followed by discrete bands of "carriers" at multiple frequencies, which then shift and move, and finally stop.

K2 Images

FT817 Images

I switched to my FT-817 for general-coverage operations.