[RFI] The FCC's Class B Standards

Dave Cole (NK7Z) dave at nk7z.net
Wed Mar 21 02:54:01 EDT 2018


I don't know why, but that bothers me, and it seems like a lessening of 
the rules, as opposed to what I think should be a tightening of the rules...

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

On 03/20/2018 07:45 PM, David Eckhardt wrote:
> Yep.  Correct.  Only in the User's Manual.
> 
> On Wed, Mar 21, 2018 at 1:10 AM, Dave Cole (NK7Z) <dave at nk7z.net 
> <mailto:dave at nk7z.net>> wrote:
> 
>     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 <mailto: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=
>             <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
>             <http://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=
>             <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
>             <http://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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> 
> 
> 
> 
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> 
> 
> 
> -- 
> *Dave - WØLEV
> *
> */Just Let Darwin Work/*


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