Re: [RFI] Light fixtures

[Bob K6UJ <k6uj@pacbell.net>]

Dave,
You are not alone.  I put in some LED strip lights under our kitchen 
cabinets.  They should have their
own call sign they were making so much RF noise. :-)
I returned them and put in fluorescent lights.  Now no problem.

Bob
K6UJ





On 7/1/16 12:36 PM, Hare, Ed W1RFI wrote:
>  From antenna modeling I have done, the decay of noise with distance depends on 
> how the noise is being coupled on to conductors and how imbalanced those 
> conductors are.
>
> If noise is coupled onto wires in the common mode, noise will generally decay 
> at a power rate of the inverse of the distance squared.
>
> If noise is coupled onto well-balanced wiring in the differential mode, 
> radiation will generally decay at much higher rates, as high as 1/D^3.
>
> For differential-mode coupling onto poorly balanced wiring, the decay rate is 
> somewhere between those two extremes.
>
> Interestingly, the balance of wiring can vary as loads are changed.  One 
> obvious change is what happens when a light fixture is switched. When the 
> switch is closed, the balance of the electrical wiring at RF is fair, and most 
> power is conducted to the load.  When the switch is opened, it opens only the 
> hot lead, effectively adding a short piece of end-fed wire to the 
> electrical-wiring transmission line, and emissions will increase by 10 dB or 
> more.
>
> -----Original Message-----
> From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of Dave Cole
> Sent: Wednesday, June 29, 2016 6:59 PM
> To: rfi@contesting.com
> Subject: Re: [RFI] Light fixtures
>
> On Wed, 2016-06-29 at 20:38 +0000, Hare, Ed  W1RFI wrote:
> > Also, where do we draw the line?  There is a major difference in kind
> > between a ham that buys a device, installs it in his or her own home
> > and has S9 noise to an antenna close to the house, and S9 from a
> > device in a neighbor's home.
> I never even thought about that...  I have a light I put up with in the Laundry 
> Room, it is LED, noisy, (S9), and about 30 feet from one antenna, and maybe 100 
> feet from the other...
>
> I only hear it on the closer antenna...  Not even detectable on the far antenna.
>
> --
> 73's, and thanks,
> Dave (NK7Z)
> For software/hardware reviews see:
> http://www.nk7z.net
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi