5 06 2010

By Ed Schumacher WA9GQK

With AT&T U-verse service becoming more established in our area, some of my experiences with it may be of interest to other hams. My first incident of RFI with the system was actually interference between two components of the AT&T equipment itself! I am classifying this as RFI because it did involve a radiated signal from one device interfering with another and is not carried over the connecting cables.

Backing up for just a moment here, the system installed basically consists of a separate modem that separates the telephone (VOIP), internet and cable television signals all being received off of your original copper wire telephone feed. The television is routed to digital receivers at each set, two being included in the basic package, with one master DVR box usually located at the first set closest to the modem location. The VOIP telephone is distributed via original wiring to all the phone jacks. The internet can be distributed via phone wiring, new cable or a wi-fi. There is also a battery backup unit located with the modem.

A short time after our system was installed, I became aware of a tapping sound on the television audio and soon determined that it was present on most signals (goood luck trying to find any dead air time on most network channels in order to listen for this with non-stop wall of sound). I eventually noticed the tapping matched the pulse of one of the LEDs in the modem and simply repositioning the modem eliminated it.

The next incident was a little more serious. Now I was chasing a dx’pedition which gave me plenty of opportunity to operate several different bands on phone and CW as well as a couple of times with the amp. It didn’t take long to finally completely blow away the U-verse. This was eventually easily solved by rerouting the CAT-5 cable (unshielded of course, you didn’t really think AT&T was going to install shielded CAT-5 did you?). The main offending mode was CW which apparently the modem saw as confusing digital signals on the input (can’t copy code?). Also, high power simply overloaded the line and caused the same thing, modem lockup. Keeping the AT&T cable away from proximity to my feedlines cured this problem. The tech who came out advised me they do have shielded cable but it is not on the trucks for general installation in homes. At least he knew what ham radio was, his brother is a ham.

All is well with the world now, right? NO. Annoying burbles have been appearing in our bands for years now with the digital revolution but the one that was parking right next to the 20 meter Salvation Army daily net frequency was really starting to annoy me. However, I had lost the use of my old portable short wave radio and it seemed every time I went out to the mobile, the signal had moved or something. Finally the day came when I had the time to do some driving around and I could copy the offending signal on the mobile rig. It didn’t take much driving around to definitely locate the signal back to my QTH for sure. By this time I did have another portable SW receiver which was also capable of copying the signal and imagine my dismay when it zeroed in on the very northwest corner of my house! A veritable antenna! To keep this story short, the receiver on the upstairs tv was putting out an incredible amount of trash via the power cube back onto the house wiring.

I eventually tried one of those little snapon ferrite cubes from Radio Shack and the signal was reduced enough to live with but still not completely gone. Now comes the big mistake. I found that the tech who did the original installation had left another power cube that had not only a ferrite cube snapped and tie wrapped on the low voltage cable, but it also had a large core on the 110v cord with the cord wrapped through it several times. AHA! (did I steal that from Oprah?). AT&T must have had some problems and maybe this was a fix for me too. Finally got everything together and connected and guess what? 20dB over S9 noise was what!

The next time I had the hours that I knew talking to AT&T would take, I made the fateful call. In the meantime I found yet another issue for them to fix. My vintage all analog Signal One transceiver would knock out the VOIP phone on 40 meters. My Ten-Tec Orion at the same power level did not. A low pass filter had no effect and I also verified that it was the signal off of the antenna and not something radiated in the shack which is right below the location of the U-verse equipment in the room upstairs.

Of course the phone tech had to attempt what I told him would be useless procedures of reprogramming the modem over the lines.  This only shifted the burble up frequency and did nothing to stop the 40M signal getting into the totally unshielded equipment. After blowing him off the phone three times with the radio he finally accepted this and contacted his supervisor for “permission” to send out a real live tech. All of this ate up a good hour or more to prove that I knew what I was talking about and the phone tech had no grasp of the technicalities involved, obviously not a radio guy.

Imagine my disappointment when upon arrival and listening to my explanation, the real live tech told me that 1. no one in their department knew anything at all about rfi issues, read no training whatsoever, and 2. he knew of no parts, filters or anything else for curing rfi being available from the company. He asked me what I could think of instead! After showing him my tests, demonstrating the offending signals and my filter on the receiver power cube, describing the loss of phone service when running the particular transmitter, etc. he just flat out stated that I knew more about this stuff than he or anyone else in his department including his supervisor! He also allowed that he thought this ham radio stuff was just about the coolest thing he had ever seen and told his supervisor the same thing in very excited tones.

I went back upstairs and removed the “filtered” AT&T cube from the one receiver (the tech took one look at it and said that those had caused interference problems between the modems and the DVRs and weren’t being used anymore) reinstalled my ferrite snapon and watched the noise drop way back down and went for a cold beer. He also told me that most of the technicians had finally been told about the tapping noise problem finally and knew to solve it the same way I did. What a relief, I followed accepted company practice!

I am now waiting for a burst of inspiration which may be some time in coming as I write this. If and when I solve all of this to my complete satisfaction, rest assured that AT&T will not be the first folks I go running to with the answers. At least not for free. I will get it all published in a ham radio forum and then offer my services to AT&T as a retired old dog engineer with some common sense and real world experience. The price? Still up in the air but believe me, it will be worth my while for the time and aggravation. Oh, the manufacturer of this mighty fine equipment? This is all the better stuff they went to from CISCO. Guess CISCO could use a couple of old engineers over there too, any takers? My first advice to them is get out of the ham bands and then shield the boxes. I would be embarrassed if something I designed for a system interfered with another part of the same system. And they just raised the equipment charge for this junk!




10 responses

31 12 2010
Robert Granville

Thanks for this. I don’t understand everything you said but this will help me navigate At&t’s customer support when I contact them tomorrow. Just got Uverse installed today and this tapping noise is driving me nuts.

18 05 2011

Thanks for everything you put there. I wish more people would take the time to write things that AT@T are doing. Yes you are right the techs they send out dont know anything about RFI. He called his boss and his boss told him to tell me to call an electrician to find the rfi. Wow. They have been here three times and nobody knows what to do. One tech even admitted to not having any training with UVERSE so he didnt know what to do. Another guy came and said let me check your ground connection. He put a meter on it and within three feet away it was 5 Ohms. He staed that was fine anything below 10 Ohms is acceptable. I just moved and Uverse is the only internet I can get here. My wife works from home so this is causing problems. Anyway if anyone has a fix for me please email me right away or a good argument with them. My modem locks up when IM on 15-17-20 meters at power of 75 watts and up. I need help with this RFI and UVERSE ISSUe. hELP PLEASE

29 11 2011

So, what do the Ham Radio guy do? When I’m on the radio, I can’t watch cable, use the internet, or the telephone.

12 10 2013
Charlie Mazoch

The technicians who do Uverse installs don’t know a thing about RFI. I had 3 separate ones at our home in Houston. The first was lucky to find our house. The second was better and understood it was a Uverse signal on m y IFR-A7550 spectrum analyzer whch I had hooked to my dipole. I had the instrument on our patio in clear view if the feed line and antenna so there was no hidden hookup yo the S/A. He said the signal was coming from our home so I had him disconnect from inside their POTS box and the signal remained the same level. After listening to my spiel on how they could prevent RFI to the 3 lower amateur bands he looked at me and said AT&T wasn’t going to do anything about my issue with RFI. I called the trouble with service number and that was a run around.
They sent out a third idiot who looked at my commercial spectrum analyzer and said their service is all over the Houston area and I’m the first radio operator to complain. He didn’t have enough time on service to substantiate that remark That evening I received a machine call from AT&T which announced the issue had been resolved and hung up. I called the number back and after a prolonged wait someone answered, I asked that an AT&T Uverse engineer be sent to our home as I wanted a person who could talk on my level of expertise. All has remained very quiet ever since. Later that evening I hooked up my S/A and discovered Uverse power levels had been reduced by 10 dbm. Whopee! Thats 3 S units a joke at best. I have been corresponding with Mike Gruber, W1MG at ARRL but feel this may be a dead end. He keeps recommending I work with AT&T to resolve this issue.
I also have sent correspondence to the resident FCC spectrum management engineer. He seems very interested but our stupid government put him on paid leave. That won’t last forever and I am not going anywhere either.
Amateur radio operators are listed as the primary operators of these bands in question. They are all ITU bands assigned by a committee under the auspices of the United Nations. The amateur bands are also under the Department of Homeland Security.
Having commercial grade instrumentation does help. I can move around our home with the spectrum analyzer and find all the in wall POTS, plain old telephone service as there are signals on the amateur bands.
Here in Houston AT7T does Uverse differently. IN older subdivisions they remove the old POTS service drop at the pole and tie it into the fiber to copper output. This in shielded wire then feeds all the old telephone wires in the house making antennas at every house. If that’s not funny enough to hook up copper pair telephone they tie the service drop to a stack box somewhere in the subdivision Unless there are high pass filters in every hookup this RFI is spread even farther.
Getting into the legal auspices the secondary user of these frequencies in question has the responsibility to shield their system from our legal transmissions. It is not our duty to be running around installing chokes on neighbors POTS boxes who complain of RFI. That is the responsibility of the secondary user. The secondary user also has the responsibility to not cause radio frequency interference to the primary user..
Check my comments on ARRL site under Uverse RFI forums. Also look at my utube videos on Uverse Interference.
Sorry about the rambing but I wanted you to know that there are others just as upset. 73
Charlie Mazoch W5VIN

12 10 2013
Charlie Mazoch

Sorry about the typos. I never took typing in school. My brain outraces my fingers but the crux of the conversation is there. Don’t allow this to become a conversation about me when Uverse RFI to radio amateur bands is much more important. If anyone needs to contact me, feel free to do so.
Charlie Mazoch

12 10 2013
Charlie Mazoch

I forgot to mention the very noisy spots seem to occur every 90 Khz + – here in Houston on 75 meters. I haven’t tested other bands yet.

27 10 2013
Charlie Mazoch

I still have the issues with Uverse RFI and on 160 meters the spikes are S9 +35 dbm. I have been busy sending the resident FCC engineer even more spectral images. ATT is nothing but a bunch of crooks. We used to have 5 Mbps copper DSL and suddenly it slowed to 1 Mbps. I called and the salesperson said ATT was having issues with copper wire DSL. I live less then 4 thousand feet from the area central office so my speed should not slow, except by a keyboard command changing it from 5 mbps to 1mbps. I once worked in one of these C.O.’s and know that to be factual.
The ARRL doesn’t even know what if any license to transmit radio frequency ATT Uverse has. A friend and I spent considerable time researching this and we reached the conclusion they are not licensed at all. Instead they use an old FCC rule under part 15 which allows them to use these ITU, international bands because they are enclosed in wires. When initial testing was done it was probably under controlled conditions.
I have been keeping a daily log on what signal levels are on 75-80 and 160 meters. I take photos of the spectrum analyzer rf levels and document everything , even the time of testing. On 75 meters the noise runs about an S7 on my FT-2000 using no RF preamplifier which translates to a -74 dbm.
The ARRL sent me an envelope seeking donations to their spectrum fund but they remain quiet on Uverse interference issues. When I asked the RFI engineer about Uverse and their license he agreed they are just probably operating unlicensed.
When GW Bush was president he signed into law a bill which places the amateur radio operator community under the Department of Homeland be used in emergency or disaster communications.
I have an initial letter all penned and will include a lot of data with copies to the FCC Gettysburg and the resident agent also seeking a claim number based on the level of radio frequency interference. The only thing I am waiting on now is for the resident FCC spectrum engineer to inform me when he is finished with priority work and can get some official readings off my tuned feeder balanced inverted V antenna. If the FCC and ARRL are going to allow ATT Uverse to just take over the lower 3 HF ITU bands by sheer money I want an answer other than the I don’t know ones I’ve gotten to date. If we are the emergency communications for the Department of Homeland Security the I guess that ATT Uverse will keep the masses happy with entertainment as all amateur radio operators remain silent.
The 80-75 and 40 meter bands are the backbone for emergency communications as when one drops out the other takes iver. I am net manager of the West Gulf Emergency net on 75 meters. It has been in constant service since 1953.
This garbage makes BPL look small when compared to Uverse over the lower 3 ITU HF bands. The ARRL took after this push in broadband and won the fight. Now it appears they have been silenced. One of my posts was never approved. Remember to follow the money.. I answer e-mail.
I have videos on Utube and have penned some stuff on my call sign page.
I have called Gettysburg FCC on 3 separate occasions asking to speak to an agent. I left messages on the 3’s voice mail and never heard back or spoke to anyone.
Follow the money is probably the only answer we will ever get.
Licensed fifty years in December and chased off the air on an unlicensed entertainment business.
Charlie W5VIN

28 10 2013
Charlie Mazoch

It’s me again with some news. I have been busy on the phone and Internet.
After conversing with the RFI engineer at ARRL headquarters I have been informed the radio frequency energy my receiver is hearing on 75 meters is not Uverse. It is a switching power supply that is changing switching rate at about 1 Khz per minute. I have worked on switching power supplies and the chopper oscillator remains on a constant frequency with the pulse width determining output voltage.
Uverse transmits using the differential method on balanced lines and this has no leakage outside the copper wires. I’ve heard of differential transmission in intra wafer wiring inside IC’s but not over telephone wires.
Most if not all transmission theory was developed before 1930 but this is a method unfamiliar to me. The ARRL is asking for donations to the protection of our spectrum but nowhere do they mention the 3 lower high frequency bands allocated to the amateur radio service on a primary basis.
I’m still working this differential transmission through balanced lines through my gray matter. It could be one RF particle of positive energy and on particle of RF energy negatively charged, In theory these would cancel each other out and RF output would be net zero. The balanced lines are somewhat harder as all the house POTS lines are of varying lengths all tied to 2 terminal posts inside the POTS box. Since the wires are all of different lengths and the frequency range is 1 to over 8 Mhz the standing waves on this mess could never be calculated.
I a way Uverse reminds me of spread spectrum transmissions. As their numbers grow the noise floor is raised. In short there are no free lunches.
All the mumbo jumbo aside if Uverse was really invisible we would not near it and it wouldn’t be shifting frequency as we transmit on legally allocated frequencies.
If anyone comes up with a design for this supposed clandestine transmission method a fortune can be made marketing the product for black ops. The transmissions would not be visible on a direction finder or spectrum analyzer Just imagine if Seal team 6 had such communications. 73
Charlie W5VIN

30 10 2013
Charlie Mazoch

More news today. I was tuning around on 75 meters and came across one of the spikes on 75 meters. Mine are about 90+ Khz apart but spoke to an amateur in Florida today whose spikes are about 80 Khz apart. I had the spectrum analyzer audio turned up and at zero sweep it sounded like modulation. I switched the FT-2000 to FM mode and was able to listen to 2 different male voices in conversation. I was unable to pick out any words.
I’ll bet my spikes are Uverse phone service. I believe these RF spikes are there and mostly unused as not all that many people around here have Uverse phone service.
I’m perplexed about this because an RFI engineer had told me these spikes were from switching power supplies. I have all sorts of silly theories which could be discussed but will adhere ti reality on thiis site. Several years ago I did have harmonics on a Diawa switching power supply but it didn’t employ any modulation method.
Charlie W5VIN…

16 11 2013
Charlie Mazoch

Hi Everyone:
I had a couple of official people with very expensive equipment drop by my QTH and collect data.about Uverse interference to my station. The backyard signals were strong enough they were hearing it throughout the neighborhood..This is finally out of my hands and I will no longer be the subject of jokes by these intelligent Uverse people who know all about RFI.
Charlie W5VIN

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