[RFI] The FCC's Class B Standards

[Dave Cole (NK7Z)]

Thanks for the info Dave...  I saw, or heard someplace that the FCC no 
longer requires a mark on the device, but just in the book...  Have you 
heard anything about this?  I can't remember where I heard it.

73s and thanks,
Dave
NK7Z
https://www.nk7z.net

On 03/20/2018 01:25 PM, David Eckhardt wrote:
> Only the FCC logo is REQUIRED to be on the device if it is Class B, home
> and small office.  The statement and other regulatory information, more
> times than not, is contained in the 'User's Manual'.  Most have a
> regulatory section devoted to this kind of stuff.  If there is no FCC logo
> on the product, assume it is either Class A (Industrial) or the supplier
> doesn't know much about the regulatory world and required markings (no
> attehtion to EMC/RFI).  This is based on some 30 years of doing EMC/RFI for
> a living.  What I write is from experience.  When we had a real FCC, things
> were very different!!!!
> 
> If it is from China or the PacRim, just assume it has not been tested nor
> any attention paid to EMC/RFI.  I have read many,.....many,.....bogus
> 'reports' on Chinese products, many of which are assembled from other
> products and piece mealed from other reports and really don't even apply.
> I've also experiencef many, . . . . many, .  . . . .  instances of false
> labeling from China.
> 
> Bottom line:  1)  When you shop for something, take a battery operated
> radio with you and request a test of the item.
>                     2)  It's hard to find otherwise, but don't buy if the
> electronics or products are 'Made in China".
>                     3)  Don't buy if in the inttruction manual or posted on
> the product, "Made of Foreign and Domestic Parts".  That's a
>                          license for Chinese switchers with, again, no
> attentioin paid to EMC/RFI.
> 
> However, the biggies like Apple and the like know the game and are usually
> to be trusted (except for their wall warts).
> 
> I realize all this reads rather negative, but its reality these days!  Just
> believe me ! ! !
> 
> Dave - WØLEV
> 
> On Tue, Mar 20, 2018 at 7:40 PM, Leonard Halvorsen <lhalvors at pppl.gov>
> wrote:
> 
>> Has everyone come to the same conclusion...
>> "*...**IF* you can find them." ???
>>
>> [RFI] LED Bulb noise Eleta E12
>>
>> I read a while ago that to avoid, or at least mitigate to great extent,
>> interference, an RF noise source must meet FCC standards for a "Class B"
>> device. What I read stated it was defined in Part 17 (it seems to be Part
>> 15 instead; possibly a typo) of the FCC rules, but I found many references
>> to it in this *official* 120-page pdf document
>> <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=
>> 0ahUKEwjgprG4lLPZAhVHulMKHQF5AQQQFggoMAA&url=https%3A%2F%
>> 2Fwww.gpo.gov%2Ffdsys%2Fpkg%2FCFR-2009-title47-vol1%2Fpdf%
>> 2FCFR-2009-title47-vol1-part15.pdf&usg=AOvVaw1Op9mrNNvD_YdVp_5mAmKU>.
>> This passage on page 23 states what manufacturers must put on such
>> devices..
>>
>> (b) For a Class B digital device or peripheral,
>> the instructions furnished the
>> user shall include the following or
>> similar statement, placed in a prominent
>> location in the text of the manual:
>>
>> NOTE: This equipment has been tested and
>> found to comply with the limits for a Class
>> B digital device, pursuant to part 15 of the
>> FCC Rules. These limits are designed to provide
>> reasonable protection against harmful
>> interference in a residential installation.
>> This equipment generates, uses and can radiate
>> radio frequency energy and, if not installed
>> and used in accordance with the instructions,
>> may cause harmful interference
>> to radio communications. However, there is
>> no guarantee that interference will not occur
>> in a particular installation. If this equipment
>> does cause harmful interference to
>> radio or television reception, which can be
>> determined by turning the equipment off and
>> on, the user is encouraged to try to correct
>> the interference by one or more of the following
>> measures:
>> —Reorient or relocate the receiving antenna.
>> —Increase the separation between the equipment
>> and receiver.
>> —Connect the equipment into an outlet on a
>> circuit different from that to which the receiver
>> is connected.
>> —Consult the dealer or an experienced radio/
>> TV technician for help.
>>
>> I tried to locate devices that adhered to this at places like Home Depot
>> and Lowes, but was unsuccessful.
>>
>> This 7-page pdf document
>> <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=
>> 0ahUKEwjSsf7jl7PZAhWStlkKHQtWCB0QFggyMAA&url=https%3A%2F%
>> 2Fwww.cableorganizer.com%2Fimages%2Fkensington%
>> 2Fmicrosaver-alarm-lock%2FFCC-rules.pdf&usg=AOvVaw2kXOZ71VpqTqByfN3bb6HO>
>>    attempts to abbreviate and interpret the legalese above. In it is this
>> passage on page two...
>>
>> Two levels of radiation and conducted emissions limits for unintentional
>> radiators are specified in FCC Part 15 Subpart B.
>>
>> The two levels are Class A digital devices, the higher less strict limits,
>> and Class B digital devices, the lower more strict limits.
>>
>> Manufacturers are encouraged to meet the Class B digital device limits.
>>
>>
>>
>> So, *the key* seems to be to find devices that meet "Class B" standards ...
>> *IF* you can find them.
>> If they are made  someplace in the Far East, that is probably impossible.
>> Compliance costs are probably too high, and most people probably don't
>> care.
>> And if you can find them, they are probably expensive.
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> 
> 
>