What happens if we have a case where AT&T is the culprit (via radiation into
ham bands from the Uverse's utilization of POTS wiring) blanketing much of
the lower HF bands?
73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie
-----Original Message-----
From: W5JR.Mike
Sent: Tuesday, October 29, 2013 2:23 AM
To: Dale
Cc: rfi@contesting.com
Subject: Re: [RFI] If you're ATT, you can do something about RFI...
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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