Topband: Radio World; Noise Floor; Where do we go from here?

Guy Olinger K2AV k2av.guy at
Sun Dec 18 18:53:17 EST 2016

On Fri, Dec 16, 2016 at 2:38 PM, Art Snapper <art at> wrote:
> There are numerous reports on the web from hams experiencing RFI from and to
> Uverse.  My main point is AT&T was complaining about receiving RFI, without
> keeping their own house clean.
> 73,

I'm sorry, Art. Just can't go along with you here. Nothing personal.

I spent some time looking up hams, RFI, Uverse, etc., based on your email.

An awful lot of the reports I found are over five years old, They
predate discontinuance of the 2-Wire (brand name) model 3800 gateway
box that AT&T used heavily on early Uverse.

That actually is a big clue, because it verifies what I've always
thought, that the 2-Wire 3800 model gateway box was the source of a
lot of their troubles. The changes between a 3800 and 3801 were
extensive, including a massive increase of buffering memory (10 or 20
to 1 increase?) to improve the built in error correction. There was a
long list that our AT&T mentor told me about, and their experience was
that the 3801 could soak up a lot of trouble out in the cables. The
drop-off in troubles attributable to the gateway is testimony to the
success of that project, as is my and my neighbor's experience with
the upgrade.

The 3800 was severely susceptible to strong ham signals on 160/80/40,
with certain frequencies capable of making the gateway reboot with 20
watts on the antenna, much less 1.5 kW. My old problem of rebooting my
and my neighbor's 3800 gateway with QRO on 160 was finally eliminated
with the 3801, which had just come out, and at that time was available
in restricted quantities. This time they were not going to lead off
with mass deployment. And they were keenly interested in my case,
described below

Several reports that looked current (2016 in email header) in
references I saw, in the text were actually referring to much older
events. One 2016 email was complaining about something the email
itself said occurred in 2001. I thought that was interesting, still
complaining about something that happened 15 years ago.

The 2-Wire 3800 is no longer manufactured, the Uverse tech support
"book" now has a list of customer complaints that automatically get an
existing 3800 replaced, regardless. No clue as to how many have been
deprecated. Nobody on my block has one anymore. Read on.

They have gone to a practice of using coax from the interface where
the cable comes up from underground to the gateway box. Twisted pair
is no longer used for that. With certain repair activities, they will
automatically replace older twisted pair from cable entrance to
gateway box with coax.

AT&T has a group, headquartered in New Jersey that is a national group
specifically formed to deal with ham radio issues with Uverse. It's
director is a well-known east coast ham, and they have the authority
to force local repair groups to follow certain procedures in
ham-related cases, and mark certain customers for automatic referral
to their group.

Anyone who has a current problem of this sort, should get in touch
with the ARRL RFI task force, who will do an entry level triage to
eliminate common issues, and then give cases that pass triage to the
AT&T group I am talking about.

They were good with my problems, really good.

They simply do not fit your description, and I do not see current
timeframe references on the internet to paint them with the colors you
are using.

What good does it do us to push and haggle to get a major company to
do the right stuff, and when they do, keep on beating them up
regardless, bringing up things that have been fixed for years?

In my case, 2010-2011...

1) I had problems with temporary main telephone cable routing due to
the construction of NC Toll 540 (extension of I-540) and its
intersection with US 64. At some point ALL the old cable was replaced.
Things were dicey with cables where they were moving roadways back and
forth to maintain traffic while bridges were being built and old
roadways dug up and replaced with heavier construction to interstate

2) The 650 foot buried drop cables from the pole out on US 64 service
road to both my and my neighbor's house were replaced and reburied
using a different route. Since 1980, when my house was first built,
widening US 64 from 2 to divided 4 lane roadway, stuff related to the
540 highway, including some mistaken contractor digs, and a couple
cable-melting lightning strikes, over time had put so many splices in
the drop, that the cable itself was way out of spec and a problem.

3) Neighbor's in-house wiring was cleaned up and rerouted to reduce
lengths and avoid some wear points.

4) The Gateway box in my house was moved to a spot recommended by AT&T
after walking around the house describing the ethernet lines. This
replaced a 120 foot ethernet run from cable entrance to gateway with a
scant 8 feet, with the gateway in my wife's office. The cable entrance
is directly underneath the window in her office. AT&T did most of the
crawlspace crawling around under the house, even though technically it
was my problem and my expense.

5) Telco Common mode current blocks designed for the frequencies and
cables in use were added at strategic points on the ethernet around
the house. They were better than my #31 material FT240 choke wraps
made after K9YC specifications. (That is NOT a dump on K9YC.)

6) 3800 gateways at both houses were swapped out for 3801's

7) These items were done one at a time followed by a retest at 1.825
watching changes in power levels necessary to reduce error correction
counts and reboots. We did this in the wee hours so we wouldn't knock
the neighbor off her IP-phone line and internet. She worked a lot
logged in to VPN from home and had a lot of conference calls.

This stretched out procedure kept me at low power until all fixed, but
it DID allow evaluation of individual steps taken, which they were
very happy to have.

If I live to be 100 and keep Uverse until my last gasp, there is no
way they will ever recoup the money they spent fixing my
extraordinary, ridiculous case from the monthly Uverse bill. But they
did get a bunch of proven facts to use on procedures in their "book"
for these kinds of troubles.

Again, anyone having RFI trouble either way with an AT&T Uverse
device, getting confused looks from local tech people who don't know
what to do, should go via the ARRL RFI task force.

73, and a great holiday season to all.

Guy K2AV

More information about the Topband mailing list