[RFI] AC Line filters- Direct-Drive Washers

Paul Christensen w9ac at arrl.net
Fri Apr 4 10:04:20 EDT 2008

For the past year, I have been fighting an issue with my own GE Harmony 
direct-drive clothes washer.  It's a great clothes washer, complete with 
serial I/O port to the dryer and a touch-screen display.  Unfortunately, 
under 47 CFR 15.103(d) such appliances are still exempt from the specific 
technical and certification standards, notwithstanding the general Part 15 
requirement that a user of such a device holds no unconditional right to its 
use when it causes harmful interference to another service.

I suspect that the last time this section within Part 15 was revised, it 
wasn't foreseeable that appliances like clothes washers could hold as much 
processing power as a personal computer.  The amount of RFI being generated 
by this washer is mind-boggling.  On 80M, it is producing signals at +50 
dB/S9 every 50 kHz or so on my Icom 7800.  If this RFI was loosely coupled 
to a resonant dipole, I imagine that its effect could be heard to the same 
extent as some QRPp transmissions -- it's that strong.

I have tried using some robust AC line filters on the line cord with zero 
effect, but I know that I need to dig deep and attack the problem closer to 
the source.  However, I need to first let the warranty period expire.

I had an opportunity to speak with two of the GE Harmony designers.  They 
were quite surprised when I found their direct inline-dial numbers on the 
Internet.  In fact, one of the engineers was responsible for the entire 
digital interface.  The first words uttered, were "look, we're exempt from 
certification with that product."   No further assistance was provided and 
of course, this was the first complaint he had heard relating to the 

Anyone have any similar experiences with the new direct-drive washers and if 
so, what specific remedy was used to mitigate RFI?  I am completely familiar 
with the general concepts of RFI/EMI abatement, but I am looking for 
case-specific solutions with actual experiences with direct-drive washers. 

Paul, W9AC

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