[RFI] Help on speed drive motor controller RFI

Tom Rauch w8ji at contesting.com
Mon Jan 29 05:36:55 EST 2007

> Please read what was actually written, Tom.

The EA5's post must have choked in a spam filter, but  my 
points are twofold.

1.) even when the supply meets or exceeds FCC and CE specs, 
it can cause bad RFI problems.

2.) even if we don't see an obvious filter it may have one

I certainly agree a unit that fails CE and is labeled CE in 
theory gives a complainer great power, but I can tell 
everyone from first hand experience units that meet or 
exceed CE can cause slight problems a mile way and can be 
devastating within a few hundred meters.

There is a chicken farm about two miles from that has a 
controlled made in the Netherlands that does pass CE and FCC 
but still has birdies several dB out of my noise on 160 

I worked on good three phase controllers at another location 
that were several hundred feet from the receiving antenna 
and caused bad problems in a moderate background noise 

It is virtually impossible for most people to test for CE or 
FCC compliance or to know if there are really filters in the 
unit (if they are necessary to pass). The bottom line is if 
it bothers the radio... and a device that passes certainly 
can be a problem. In such cases, and they are common, 
filters from the manufacturer often are useless.

73 Tom 

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