ARRL

Forum Home - Rules - Help - Login - Forgot Password
Members can access, post and reply to the forums below. Before you do, please first read the RULES.

Uverse RFI

Oct 4th 2013, 23:04

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I live in a 57 year old subdivision in Houston. For quite a few months I have been seeing all sorts of broadband garbage on my DMU-2000 pan adapter. After hooking up an IFR-A7550 spectrum analyzer the interference source was evident. I have called AT&T several times and they can't even understand what the spectrum analyzer displays.
Our Uverse is fiber to the pole boxes and from there on old unshielded POTS drops to the houses to be hooked into the old unshielded POTS wiring in homes.My noise level is S9+10 every 60 or so Khz and these high signals move up and down in frequency several Khz. I am net manager of the West Gulf Emergency Net which has been in constant operation since 1953 and one of these noisy clumps of RF energy is on the frequency we operate on 75 meters.
I've done internet searches and on one forum have discovered that the FCC is supposed to be working with AT&T Uverse to eliminate amateur radio interfering with their service. On the Uverse site they tell amateurs how to use antennas with less ERP and how to prevent coaxial shield from radiating by grounding.the shield. I always used a balun for decoupling coaxial cable. How can this be the fault of amateur operators when the frequencies in question are assigned to our community on a primary basis and AT&T is allowed to use these frequencies in a non interfering basis. They are supposed to be in a shielded environment.to protect Uverse from amateur radio transmission. I refuse to use the word RFI because because unless the amateur transmission interferes with another primary user we are NOT interfering.
This has become a Pandora's box when Uverse is wired using such
prehistoric techniques.
I had a conversation with 3 separate Uverse technicians on how their service could work quite well in close proximity of amateur radio transmitters.
They could run fiber to a different POTS box and convert at this point to WIFi or shielded coaxial cable to an indoor modem. The WiFi frequencies used to belong to the amateur community. Lets hope the HF amateur bands don't go the same way.
I'd bet when AT&T was allowed to use these frequencies open wire feeders and existing home POTS lines were not authorized. But if the cat is away the mice will play. Uverse has become our worse threat on the lower HF bands. since their signals involve so many square waves the harmonics are seen at 21 Mhz on my dipole.
AT&T Uverse brags their system is quite robust and designed to operate in high RF fields which is very true. It can frequency hop in an instant to avoid interference and as soon as the RFI is gone hop right back..
We will be blamed for cutting our neighbors Uverse modem off and splattering their TV, Internet and telephone by AT&T Uverse..
I am certain all parts of the country are not wired to AT&T Uverse using such shoddy practices as in my neighborhood. With proper wiring techniques we could coexist very well. Many years ago when Comcast moved unto our neighborhood the same issues arose but they cleaned up their act.
If any of us as amateur radio operators have similar problems do something about it.
AT&T Uverse is designed to survive and keep on working in any RF environment regardless of power levels. It's like placing an armored fox in the chicken coop.
Oct 6th 2013, 22:02

AA6E

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I have a fair amount of experience with Uverse -- until I dumped them for cable this past year. All my troubles were related to ham signals at the 50 W level and higher (HF) getting into Uverse and clobbering my Uverse service. The incoming Uverse signal was just about undetectable in my receivers. My service was FTTN (fiber to the neighborhood), not on the pole. I don't know if that would change the situation.

So I have to ask why do you think your problems come from Uverse? Can you disconnect and make it go away? Probably not, I know.

The noise problems you describe are the kind I see on all kinds of equipment powered by switching-type power supplies. Have you tried shutting off all devices in your house (switch off all breakers one by one) to see if it goes away?

73 Martin AA6E
Oct 12th 2013, 03:20

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I hate to disagree with you but my commercial spectrum analyzer tells me it is Uverse transmitting their information on old non shielded copper pairs in my subdivision. Would you care to enlighten me how an entity can transmit on amateur radio frequencies with no RF shielding and not be seen by a spectrum analyzer.. Why do you think amateur operators get into the Uverse system? Improper shielding with the Uverse system. We are the primary user and as such the secondary user is responsible to clean up their system. Check my 4 uploads on Utube at "Uverse interference" using my FT-2000 pan adapter and IFR spectrum analyzer. I can walk around our home with the spectrum analyzer and when near an old POTS line it jumps up in amplitude..
I'm in the back yard and under the dipole which is hooked to to the S/A and it's still there. I unhook the service drop from my POTS box and it's still there. All that rambling aside the Uverse tech said it was their signal but they weren't going to do anything about it. This started when Uverse was being installed in my neighborhood and gradually put me off the air. I also know what switching power supplies can do. I had a Diawa switcher and it had issues with birdies on 75 meters but had a heterodyne present and this stuff is constantly shifting frequency with no heterodyne. All that aside all Uverse needs to do to prove I am the guilty party is to bring their own spectrum analyzer. These people don't own one nor have the knowledge to operate the instrument. If I were operating as a secondary user on frequencies assigned to other primary users this would be my first instrument. I used to work for for SW Bell in a central office in Houston as a network technician and know what purpose 8 Khz multiplexer pulses serve and I have some spectrum captured that shows these pulses.at times.I forwarded some spectrum analyzer scans to our local FCC spectrum management engineer and he seemed interested but is on paid leave due to the federal government shutdown. I will wait and see how this plays out. Charlie W5VIN..... .. . .
Oct 12th 2013, 21:38

AA6E

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Charlie,

I can't argue with what you're experiencing. Sounds like no fun at all.

Maybe your U-verse is structured different from mine. Mine uses VDSL2 modulation, which combines 1000s of individual carrier tones into a very wideband noise-like signal. It has a flat spectrum up to 7 or 8 MHz with no peaks that I could see. In my situation, my line length was over 2000 ft from the "VRAD" (fiber to copper box in the neighborhood). The receive levels at my house were very low -- practically undetectable with my spectrum analyzer or ham receiver.

The low receive levels are why we have trouble with ham transmitters. Our rigs generate high level signals that can overwhelm the sensitive Uverse receiver in your RG (residential gateway) and cause freezing up or resetting.

There are more details at my site - http://www.aa6e.net/wiki/Uverse.

Good luck with your interference!

73 Martin AA6E
Oct 13th 2013, 01:50

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
As the primary user of the frequencies in question the secondary user should operate in a shielded environment so their sensitive receivers don't overload. Potting radio signals on unshielded wiring is not exactly a well designed system. Especially when the signals in question are assigned on a primary basis to other users.
AI&T wanted to make an end run by doing things cheaper so they built a transmitting system capable of withstanding an EMP and then cry wolf when the primary frequency user trips out their modems and gets into the neighbors TV and Internet.
Had AT&T designed the system to transition from fiber to WiFi at the POTS enclosure or ran coaxial cable to the POTS enclosure and then in shielded cable to the modem they would not be hollering uncle
How come don't amateurs have issues with cable transmission systems? Because they operate in a shielded environment and did so from day one. In my area they also do not use the lower HF amateur radio bands to transmit their information. I had an issue with them after the company started and the FCC did a search and made them redo the aluminum shields where they had crawled out from the fittings. Problem solved.
I put up another two Utube videos on the interference AT&T is causing me at my home and neighborhood. It's under Uverse interference. I want the entire amateur radio community to see what can happen to frequencies assigned to them on a primary basis. Someone dropped the ball on this pathetic Uverse distribution and I can tell you why.
AT&T did not want the additional cost of having to put their service in a shielded environment all the way to the modem so they cut corners allowing them to cut monthly rates. Most of the time this works, until that amateur certain radio operator with quality test equipment calls then out.
As you probably still do I once worked for the local phone company
as a network technician in a central office. In my day we weren't dumb enough to transmit on frequencies as secondary users without using shielding.
I don't care what type of signal they transmit if it occupies the same space as the signal I am interested in communicating with. Two signals cannot occupy the same frequency without raising the noise floor and causing the receivers AGC to pump and destroy communications for CW and SSB operators.
Perhaps amateur radio operators should just allow the secondary user the first 60 dbm above the -130 dbm noise floor and then we can coexist in a friendly atmosphere.
The 160, 80-75 and 40 meter bands are important to amateur radio as one may work for local ground wave communications and then stretch out for longer coverage. There are probably dozens of nets on 75 and 40 meters which perform communication duty in disasters or emergencies.I am net manager of a 75 meter net which has been in constant existance since a hurricane roared through Orange, Texas in 1953. As net manager I can't even get on the air because Uverse refuses to lower it's power level as they expect from me. No I'm not happy because a 95 year old retired physician is having to take my place as net control station. One of those famous energy bumps Uverse transmits manages to hang around our net frequency.
December 31, 2013 I will have my license 50 years. What a wonderful present from AT&T. 73 Charlie .
Oct 13th 2013, 12:05

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I have 4 very nice video clips on Utube showing the effects of Uverse on communications through out the 75 and 80 meter amateur radio band. I am going to be adding some more video clips of the 160.and 40 meter amateur band also. This garbage about how we should be kind and share our frequencies with Uverse is just that. So it's wonderful technology and the amateur high power transmitter causes it havoc. I could care less about Uverse technology as they are leaking their RF into the ether in my neighborhood at levels so high I'm off the air except for very close contacts. A station has to an S9+ to be armchair copy. Unfortunately most of my net members reside f85 to 240 miles away and I am unable to copy these at 0800 CST. I also belong to another 75 meter net which meets at 1830 CST and can't copy 50 percent of the stations.
.I'm biding my time and waiting for the FCC spectrum Management engineer to get back to me after he is allowed to return to work. Any entity that places an RF signal on a twisted pair phone line is doing nothing but causing interference for primary users of these frequencies. I find it hard believing this was allowed to fly under the radar. Once that Genie's bottle is opened it's hard to get it back in.
It's like having an armored fox with a Klingon cloaking device watching the chicken coop.
Martin, you must be the Uverse engineer Mike Gruber of ARRL headquarters said could help me with my Uverse QRM problem..
Telling me how Uverse operates is not going to solve a thing. They are invading amateur radio spectrum ever since their signals appeared on our receivers. Charlie W5VIN..
Oct 13th 2013, 21:14

AA6E

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Charlie,

I have no relationship with AT&T except I am a former customer. (I'm retired and a volunteer at the ARRL Lab.) I agree that Uverse has problems with ham radio, but the fact is I just did not see incoming interference that I could pin on AT&T. (I've got plenty of other interference, apparently coming from neighborhood sources over power lines.)

I'm not saying you don't have incoming interference, but how do you know if it is coming from Uverse?

Could you make an RF probe (small loop) connected to your receiver or spectrum analyzer and sniff the fields around the Uverse cable? If they're radiating anything, the signal should be a lot stronger when you're listening close to the cable.

My Uverse connection was "POTS" from the neighborhood VRAD to my power pole. As part of the installation, AT&T installed a new "drop" cable from the pole to the house. They said it was twisted pair, which should be much better than the old style untwisted (?) drop. It made no difference for me.

73 Martin AA6E
Oct 13th 2013, 23:22

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I have been searching for a 4 to 1 balanced to unbalanced instrument balun but will probably just use a T pad resistive attenuator and hook this to my service drop at the pots box and use the spectrum analyzer to measure signal levels and signal signature at the source. Yes I do believe my QRM is AT&T Uverse for at least 2 reasons. This garbage service started perhaps 6 months to a year ago. I had Center Point Energy out numerous times and they had the power lines cleaned for a 20 block area around me. The other reason is the second ATT t-ech looked at my spectrum analyzer and confirmed the signal was theirs but they weren't going to do anything about it.Tomorrow I may do some measurements at the service drop.
I believe I figured out on my own how this system operates. Every 90 or so Khz the RF energy bumps are sending and receiving packet clusters. If a certain percentage are dropped the power output is increased and then lowered as the packet cluster loss becomes less. These clumps are constantly moving at a slow rate over 12 to 20 Khz area but go up and down in frequency.This abomination does not operate in the MDS RF levels but occupies everything from -128 dbm to at least -70 dbm power levels as measured at 50 ohms. That's a huge chunk of operating level. The constantly changing power level is causing my receiver AGC to pump which effects amateur conversation even if the garbage is non detected by my form of demodulation. Tomorrow I will do the nice thing and perform those tests at the POTS box so there are no more questions. This RFI is not the Martians trying to communicate with me. If I receive the signal in our home especially when near phone lines and from 2 separate dipoles antenna and it started when Uverse was being installed in our neighborhood what else can it be..I could add the FCC spectrum management engineer was interested in my QRM issue after I told him I only checked signal levels at my dipole. I sent him the same photo's I had sent to Mike Gruber. Hopefully he will have his teeth sharpened after a drive through my neighborhood. After reading some of that material on the AT&T RFI forum I was convinced Uverse is in trouble. The author never admits one error AT&T committed. The entire article is ATT
pontificating and blaming interference on amateur radio operators.
If one was to believe their spiel we would all be transmitting into dummy loads. Charlie W5VIN
Oct 14th 2013, 20:39

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Marvin: Today I completely disconnected the AT&T service drop. The interference may have dropped by 5 dbm. I went back to the POTS box and removed all phone lines except the Cat 5 modem cable. The interference increased to within a couple of dbm of the level of having all lines connected. The signal still looks the same. I took quite a few video clips at different spectrum widths and filter widths. The signal dropping by so small an amount after removal of all phone lines except the Cat 5 a large area around our home will have to be cleaned up. Cat 5 is NOT shielded cable and will radiate RF. It's twist only allows a faster data transfer rate. If this system sends out packet clusters and then looks at return loss percentage this tells me when first set up in the neighborhood some power level is set initially and after this if data loss occurs the power is turned up. There is no data available online about the system and relatively few comments pro or con.
The data collected today shows the different spectrum analyzer settings and is video of an open input or hooked up to the dipole antenna.
I'm tired of this CYA and circle the wagons phone company and at this time am waiting on the federal government shutdown to end.so I can turn this over to the local FCC spectrum enforcement engineer.
When I was dealing with the AT&T technicians the only name I got was the techs first name and phone number. When I asked for his supervisors name and number at first he claimed to not know. After 14 years he didn't know his supervisors name. He finally coughed up that name and number.This was the tech that said my spectrum analyzer was displaying a Uverse signal.He probably suspected I wasn't going away quietly Later when I called his supervisor he would not answer the phone. I waited a few minutes and called back using a cell phone and the man answered.
Like someone once said it ain't over till the fat lady sings.Who knows she may also be paroled by our federal government. 73
Charlie W5VIN .
Oct 16th 2013, 01:07

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I capacitor coupled my spectrum analyzer to the service drop inside the POTS enclosure. Somehow I created a band pass filter that passed from 3.75 Mhz to 4.8 Mhz.Doing this made my dipole signal to have the same pass band. That indicates the service drop is radiating a lot of RF. Probably every service drop is if they are unshielded, not grounded and near my QTH.. I wish to add this interference was in full swing long before I got Uverse internet. I was already off the air several months ago.
I just took a test lead and wrapped several turns around the service drop and got some inductive coupling. The signal there looks exactly as my dipole receives. It's time to quit chasing my tail and file a formal complaint with the FCC. It will be worded to the effect that no radiator shall be allowed to generate harmful interference to any other licensee, in my case a part 97 licensee. and primary user of the frequencies in question This will cause a complaint number to be generated and assigned for clearance.This also gets me out of the loop as the interfering party will be dealing with the FCC instead of me. After being told by one Uverse employee they will not rectify the problem and another that they have this system all over Houston and I'm the first ham to complain.I asked for a Uverse engineer to come over and instead received a robotic call informing me the problem had been resolved. Then the line went dead. it's time for someone else to collect official data on RF levels in the neighborhood. 73
Charlie
The Uverse people don't even own spectrum analyzers or tunable RF field strength meters.much less know how to use the equipment. They just run wires from pole to house and all is well in the RF spectrum...
Dec 18th 2013, 19:52

W5VIN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
ATT Uverse came out and cleaned up the 4 interconnect enclosures closest to our home. They also added more grounding bonds On my recommendation they added some brass screen wire to the inside of the cover. Those enclosures are not RFI proofed. Before this work the enclosure had a strong signal on my Bendix 555 Marine DF unit After the mods I had to advance it's RF gain to full in order to hear it at 20 feet distance. I still have Comcast leakage from the next door neighbor. When the modem starts communicating it wipes out 18 and 21 Mhz. Tomorrow a field service tech is supposed to come out....If I didn't get lied to.
Unfortunately until the FCC got involved ATT Uverse was the same way. It took some time even after the FCC kept calling.
Comcast's technician said he knew exactly what the problem was.
Yesterday evening before the neighbor got on Comcast my S meter was on zero for the first time in a year.
Charlie W5VIN
Jan 6th, 07:50

WA3HSC

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I too am having havoc created by U-verse equipment here in Orlando, Florida. The internet boxes put out so much RF as to make all of HF and AM radio unusable. Also, the cable coming into the house causes S9 to 40 over S9 interference!

Has anyone had any luck with ATT, U-verse fixing the problem?
Jan 29th, 18:42

N8KC

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Wow.. glad I came across this. We had ATT Uverse put in months ago. At the time, I was not terribly active on the lower bands and failed to notice the dramatic change in my noise levels on 40m. When I did first notice it, I had thought it was a return off local Edison power line problems... a near constant source of RFI issues near me (old hardware that they refuse to replace until it breaks). But, this RFI sounded different upon listening closer and hadn't been there prior to the Uverse installation. It's not the typical "buzz" with a distinct AC note like Edison's RFI... it's more of a constant low "rushing" sound.....

Back to Top