> Just to say that switch mode supplies CAN be made to be as RF quiet as any
> linear supply.
Charlie,
The problem is not pervasive with legitimate companies like Astron, Samlex
and scores of other switch-mode producing technology companies. To a large
extent, the problem comes from off-shore Asian suppliers of subassemblies
that become embedded into appliances -- appliances that require no FCC
certification in the U.S. under Sec. 15.103(d). Moreover, importation rules
under Sec. 2.1204(a)(2) exempt from certification and equipment
authorization all radio frequency devices being imported into the U.S. where
such devices do not otherwise require FCC certification (e.g., appliances
under Sec 15.103(d).) Quality companies seek some form of certification for
their devices whether they are compelled to comply -- or not. Most
importers don't care and seek only to design their products with the minimal
amount of quality and testing required (if at all) to get the product into
the market.
As another example, I recently installed halogen accent lighting in my home
office and discovered that a switch-mode "electronic transformer" was
spraying gross amounts of RF into my home electrical wiring. The unit
contains no certification labeling and is imported from Malaysia. This was
no on-line Internet purchase; it was purchased from my neighborhood Home
Depot.
So, when I state that the problem is growing as a result of the expanded
proliferation of switch-mode technology, it's a fact. Unfortunately, the
bad guys are out-numbering the good guys -- and it will stay this way until
the Commission acts on it own or through a Petition for Rulemaking to amend
Part 15 to reflect the reality of the times.
Paul, W9AC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|