Hi, Dale and others. Many of these new industrial high efficiency lighting
systems are generating significant broadband noises from near 650 MHz to close
to 900 MHz. They fall under Part 18. They impact many licensed radio services,
including Public Safety, both uplink and downlink. Fortunately, two of the
manufacturers have acknowledged the problem and engineered a fix and are
replacing hardware. A few issues remain, but the process has been pretty good.
Some large national retail stores changed out their lighting and changed it out
again.
You can imagine how a building owner might react to getting a knock on the door
letting them know their brand new (expensive) high efficiency lighting system
is the source of interference to numerous licensed radios systems requiring
them to disable it. The lighting often is either primary in building lighting
or outdoor parking/security lighting. Not a good situation. Most owners are
cooperative to seek a solution, a very small few are not.
Disclaimer, I do indeed work for AT&T (Mobility side) and interference ingress
and egress is one of the areas I am involved with. It's amazing the amount of
broken (faulty) electronics we encounter every day. It seems like an unlimited
supply.
tnx
Mike / W5JR
> On Oct 29, 2013, at 12:45 AM, Dale <svetanoff@earthlink.net> wrote:
>
> Tom,
>
> I suspect that your post will generate several replies. Mine is as follows:
>
> 1. Amateur radio is also a LICENSED service. We CAN invoke the FCC, but
> admittedly, it takes several more steps to get action than what AT&T had to
> do in Houston. It should be noted that 705 MHz DOES fall within the range of
> controlled emissions for Part 15 devices, whereas 3.5 MHz does not.
>
> 2. This case seems to be pretty much like the situation hams face when a
> neighbor has a plasma TV or touch lamp or battery charger that are incidental
> radiators and cause grief to radio systems. FCC may not do anything about
> radiated interference on HF because of non-coverage under Part 15, so you,
> the ham, then have the option of confronting the neighbor directly about an
> offending device; the result is often similar to what the defendant in this
> case is doing to AT&T. The difference is, of course, he'll probably lose.
>
> 3. The one area in which FCC has gone to bat for hams has been with the
> electric power companies when the interference can be shown to emanate from
> distribution power lines and associated equipment. I have had two
> situations, one in IL and the other here in IA, in which the local power
> company was very helpful and even quick in fixing severe RFI problems that
> were affecting me. I did not invoke FCC, but I think the power companies
> were well aware of the sort of pressure or fines that can come from amateur
> radio RFI complaints.
>
> 4. The situation here is not related to power distribution problems, and
> neither are plasma TV or other consumer garbage RFI sources, so I suspect
> that the fact that the light fixtures are putting out big sigs on 705 MHz is
> a huge help for AT&T in getting action. Incidentally, it sure would be
> interesting to learn just how devices made to operate at relatively low
> frequencies can generate strong harmonics or spurs way up into the UHF range.
>
> 73, Dale
> WA9ENA
>
>
>
>
>
>
> -----Original Message-----
>> From: K8TB <k8tb@bosscher.org>
>> Sent: Oct 28, 2013 3:26 PM
>> To: rfi@contesting.com
>> Subject: [RFI] If you're ATT, you can do something about RFI...
>>
>> Interesting read...
>>
>> "http://transition.fcc.gov/Daily_Releases/Daily_Business/2013/db1028/DA-13-2077A1.pdf";
>>
>> But if it is on 75 meters?
>>
>> Tom K8TB
>>
>>
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>
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