[AMRadio] FCC Non-cooperation (was ILLEGAL STUFF ON E BAY)


Robert Nickels ranickel at comcast.net
Wed Mar 17 12:35:43 EDT 2010


Not to detract from Steve's point, because I agree that RFI from 
unintentional radiators is a major problem for hams, especially those 
who enjoy full-range AM audio on HF.  But it's important to understand 
how the FCC approaches the wide range of Part 15 issues - here are a 
couple of good resources:

FCC:  http://www.fcc.gov/oet/ea/procedures.html#sec1
ARRL:  http://www.arrl.org/tis/info/part15.html#Myths
An A2LA-certified RF test lab:  www.radiomet.com/documents/FCC_Guide.pdf

Once you're familiar with the terminology used to characterize 
unlicensed devices,  I think most will agree that our problems stem 
primarily from both Class A (intended for commercial, industrial, and 
business use) and B (residential)  Unintentional Radiators.  This can 
involve both Conducted (interference that is carried along power lines 
and other conductors to other devices, i.e. our receivers) and Radiated 
emissions (what Steve measured with his spectrum analyzer).  The vast 
majority of such devices are subject to Verification, which is the 
lowest level of compliance.  Manufacturers are on the "honor system" to 
do the appropriate testing and label the product accordingly.

Even when manufacturers make a good faith effort to comply with Part 15 
Verification requirements, the real world implementation may not reflect 
what was seen in the laboratory.  Take for example the noisy LED traffic 
light that Steve posted about some time ago.  Suppose the manufacturer 
recommended that shielded cable be used between the switchmode 
controller and the lights to mitigate radiated RFI, but the installers 
just re-used the unshielded wires that were used for the old 
incandescent systems.   Instant antenna!  As hams, we know the length of 
the wires and whether they're run inside a metal pole or along the side 
of a wooden one will make a big difference also.  Just a made-up example 
to show that the problem may often not be as simple as going back on the 
manufacturer of one of the devices in question.

Still, the intent of Part 15 is to protect licensed users from 
interference from unlicensed devices, and the best option we have to 
enforce current regulations (or potentially get better ones)  is to 
continue to elevate our concerns to the FCC and those who oversee the 
agency.

73, Bob W9RAN




More information about the AMRadio mailing list

This page last updated 15 Dec 2017.