[RFI] Variable speed drives

[Kelly Johnson]

Variable speed motors don't necessarily have to cause RFI.  I bought
an LG High Efficiency Washer/Dryer pair 1.5 years ago.  It clearly
uses this type of microcontrolled technology and it is RF quiet.
There is less RFI from these devices than from my 13 year old CRT
television.  My tower is only about 30 feet away from the washer/dryer
and 65 feet tall.  I've never heard a peep from them.  My FT-817
doesn't register anything on the S-Meter until it is about 12 inches
from the front panel where, I assume, the micontroller is.  My FT-817
registers noise from my TV at about 24 inches.

Some manufacturers cut corners and build junk and others know how to
shield things properly.  Variable speed motors aren't the problem.
Bad engineering of whatever technology is the problem.

What we really need (and will never get) is an FCC requirement that
manufacturers fix, replace, or refund money for any device found to
cause harmful interference.  The real problem is that there isn't
enough incentive on the manufacturers to clean up their act.  There
aren't enough hams to make it an issue.  The manufacturer just tells
your neighbor that "it's that ham operator's fault".  If the consumer
could force the manufacturer to resolve the issue (or refund your
money) things would be much better.  Unfortunately, it will never
happen.



On 3/26/07, dgsvetan at rockwellcollins.com <dgsvetan at rockwellcollins.com> wrote:
>
> All,
>
> Knowing the many previous posts on this reflector regarding variable speed
> drives for home applications, here is an article that probably will not
> make you rejoice.  There is a lot of interesting information, but I am sure
> you all will note the complete non-mention of RFI.
>
> 73, Dale,
> WA9ENA
>
> http://www.electronicproducts.com/ShowPage.asp?Filename=irf.aug2006.html
>
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