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Re: [RFI] FW: ARLB022 FCC's OET Clarifies Emissions Compliance Testing f

To: rfi@contesting.com
Subject: Re: [RFI] FW: ARLB022 FCC's OET Clarifies Emissions Compliance Testing for RF LED Lighting Devices
From: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Sat, 2 Jul 2016 03:57:00 -0400
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
Kurt, your mention " If something was to change, what about the millions of RFI generating devices that already exist and are causing the current problems?" reminds me of the lousy signal (IM products) put out by most SS finals (RFI) and the drive for cleaner signals. Were ALL manufacturers forced to use dynamic predistortion in rigs and amps, it most likely would be decades before we'd see any noticeable difference in the bands. With switch mode wall warts, it most likely would be many times that as those are thing that "get thrown in a drawer" and will show up from time to time until they fail.

I believe, most people connect the new wall wart to the new device and though the old device may be thrown in the trash, the SMPS gets thrown in drawer. I have "boxes of the things". Many were power for I know not what.

Every time a new one shows up, I have to test it. Fortunately for us and unfortunately for many users, they often use them if the connector fits whether the voltage and current are proper or not. The ones I have vary from 5VDC to 19 or 20VDC. Many are AC over a similar range. Current capacity varies from a few hundred MA to over 10A. Unfortunately those for external drives vary more with the connectors than voltage or current.

"SOMETHING" has shown up in the neighborhood that totally wipes out 160 and 75. 40 is useful in spots. Two or three weeks ago, the band was quiet. It's audible above 40, but near the noise floor with a noise that sounds like arcing. On the higher bands it can be heard across the bands, but it's every 60 to 70 KHz on 40 and peaks at 10 over On 75/80 it's more it's twenty over close to every 388 KHz. On 160 it peaks at ten over on 1.862, 1.925, & 1.987, or about every 62-3 KHz

It has a pause every 30 to 60 seconds that has a Berriee sound, followed immediately buy the buzzing sound (a series of pulses close enough together
 to sound like a buzz. .

73

Roger (K8RI)



On 6/30/2016 Thursday 6:07 PM, KD7JYK DM09 wrote:
: I'd guess it's a start, at least!

I predict no change other than a run on Part 15 labels which the products
have always had.  Adding an "a" or a "b" to the report before manufacturing
is unlikely to mean anything except the maufacturer for a moment, long
enough to push the same junk through.

"[W]e have found that emissions from RF LED lighting devices are
non-periodic, broadband in nature, and are produced as a byproduct
of the internal driver circuitry within the RF LED lighting device,"

What is a "RF LED lighting device" and since LEDs run on DC, why does such a
potentially troubling circuit exist beyond a battery and rheostat?

the OET "knowledge database" paper said. "These types of emissions
have adequate energy and potential to generate radiated emissions
well above 30 MHz."

Yes, I hear them well into the 300 MHz range when I'm out and about.

"was pleased to see the FCC's OET clarify the test measurement requirements.
He said ARRL is generally hearing more RFI complaints stemming from RF LED
bulbs."

Can someone clarify an RF LED bulb?

"the Lab has seen LED lighting devices causing problems in the 2 meter band.
"Since conducted emissions limits do not apply above 30 MHz, radiated
emissions limits can be the first line of defense against RFI at these
higher frequencies."

That would be nice.  I've been working with aircraft communications since
mid-last year and noise is a big problem at ground level, often rendering a
receiver useless.

If something was to change, what about the millions of RFI generating
devices that already exist and are causing the current problems?

Kurt

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