[RFI] FCC Limits on Harmful Interference: Clarification

EDWARDS, EDDIE J eedwards at oppd.com
Tue Dec 31 08:21:07 EST 2019


Kim has it right again!  

Kurt, the worded definition is better than any numbers.  Why?  Because all the utility needs to do is find an instrument that shows the number the FCC wants it to be in order to send data to the FCC proving the utility doesn't have to do anything since they met the number.  One number on one HF frequency and they're off the hook.

You do NOT want a specific number that can satisfy the FCC and utility.  The verbal definition requires that the ham be satisfied, not a specific data number.  

Do you get it now?  

73, de ed 

-----Original Message-----
From: RFI <rfi-bounces+eedwards=oppd.com at contesting.com> On Behalf Of Kim Elmore
Do you mean -120 dBm? How do you measure that? At what point is the 
radiated power measured? How do you connect to a device to measure it?

Besides, why stop there? Why not simply make it *undetectable*? As in, 
nothing known, no matter how it's connected, can detect if the system is 
operating?

Well, put simply, nothing will pass such a test. A level of -120 dBm is 
around the MDS for many receivers at the input terminals. I still say 
that if we *insist* on a standardized limit, someone will inevitably get 
screwed because you can bet your sweet bippy it won't be -120 dBm no 
matter how it's measured.

Kim N5OP

On 12/30/2019 10:01 PM, KD7JYK DM09 wrote:
> "We do NOT want a measured level of interference to define "harmful 
> interference"."
>
> How about just making it very, very low.?? -120dB at one meter from mHz 
> (1/100th of 1 Hertz) upward is adequate, should keep everyone, and 
> everything happy, and not unreasonable for equipment that shouldn't be 
> spewing interference anyway.
>
> This allows for a wide range of very poor design, without negative 
> affects.
>
> We have RFI because its allowed, why not flip it from "fine, within 
> these levels", to "knock that crap off"?
>
> Kurt
-- 
Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP 
SEL/MEL/Glider, N5OP, 2nd Class Radiotelegraph, GROL)

/"In theory there is no difference between theory and practice. But, in 
practice, there is." //??? Attributed to many people; it???s so true that it 
doesn???t matter who said it./



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