Severe OTA Interference From New Digital Services Tower

[GerryB]

Here is a video where I turn a simple non-amplified dipole around 360 degrees a few times. At one point I can get channel 60, but when I moved my own body the signal quickly went bad. Again, I used to get this channel perfectly no matter where I held the antenna.

http://s214.photobucket.com/albums/c...ipoleunamp.mp4

Confirmed Rogers is testing in 700 MHz band for LTE:
http://www.reuters.com/article/2010/...6950MG20101006

[ShawnD]

Originally Posted by majortom

What both you guys are saying is unreasonable. Your expecting every consumer electronics manufacturer to design every product assuming that there's 1000W ERP or more entering in every consumers front window, from a distance of 70 meters away. Silly.

But it is possible to specify performance limits to ensure products work as expected in typical environments.

In Europe the EMC (Electromagnetic Compatibility) regulations require susceptibility testing to ensure products work in typical environments. I don't remember the limits, but the industry specific standard for a product I was involved with required field strengths of 20V/m in some bands with no unacceptable degradation in performance. This is a strong enough signal that it would have been unsafe to be in the test chamber while the test was running.

Let's compare the requirements:

North America (FCC Part 15, IC ???)

• Radiated Emissions
• Conducted Emissions (Power, Ground and signal cables)

Europe (EN 61000-*-* and other industry specific standards)

• Radiated Emissions
• Conducted Emissions (Power, Ground and signal cables)
• Radiated Susceptibility
• Conducted Susceptibility (Power, Ground and signal cables)
• Surge (Power, Ground and signal cables)
• Fast Transient (Power, Ground and signal cables)
• ESD (Electrostatic Discharge)

[GeorgeMx]

Originally Posted by stampeder

...While giving advice to GerryB to "move out" of his home is understandable, the gist of this thread is really about what recourse he has to getting the RF radiation effects reduced or stopped.

As Stampeder, the moderator of this forum, participated in the RF safety discussion I believe it is on topic in this thread.

Almost every human endeavour has both risks and rewards. As a society, we accept the principle that benefits to the population as a whole outweigh losses to the few. For example, every transportation system in existence has risks of injury and death for both users and bystanders. The risks are well known and quantified but we continue to use these systems because of the social and economic benefits, and convenience. Telecommunication and broadcast systems provide social and economic benefits and convenience, and RF technology is a key component. Use of RF energy is regulated based on the things we know about risks to human health and set at a level that allows practical use of radio systems. Exposure level regulations are the manifestation of the tradeoff between benefits and risk.

For another example, consider individuals with severe allergies to nuts or seafood that cause discomfort, ill health or even death. As a society we don't ban the production, packaging or use of these substances which are extremely dangerous to some people. Instead, food is labeled and restaurants put warnings on the menu. Persons susceptible to the allergies are told to get an epi pen, know how to use it and carry it at all times. The responsibility to mitigate the risk lies with the individual affected because we as a society are not willing to give up the benefits of having these foods.

When it comes to issues about RF exposure, very few individuals have the qualifications to assess the research and determine if relevant regulations should be tightened or loosened. There is no evidence of any epidemic of disease linked to wireless usage. If and when repeatable studies show clear evidence that current levels of RF exposure are responsible for health issues then the experts can balance the benefits against the risks. A possible outcome from expert analysis and deliberation might still leave the RF exposure regulations at current levels on the principle that the benefits outweigh the risks.

[ota_canuck]

Of course health risks are a very important part of this discussion as well as the fact that current regulatory considerations do not protect those who choose OTA rather than paying the fat cats. The average guy can't afford to hire lobbyists to get their voices heard at the front line of IC discussions. The fat cats hire lobbyists to force the issue of squeezing the airwaves of OTA to force viewers to pay and then they raise their rates to be able to pay off the lobbyists.

It's all about the money, It's all about wringing out the spectrum to make everyone pay. It's about squeezing an end to free OTA. It's about bending over to please the fat cats even at the risk of health or inconvenience to the general public.

A possible outcome from expert analysis and deliberation might still leave the RF exposure regulations at current levels on the principle that the benefits outweigh the risks.

Are you suggesting that it's OK to risk killing people with potential health issues in order to make the fat cats happy?

[GerryB]

Well it has been almost 2 weeks and no response from Rogers. The only change Ive seen is an increasing level of measured RF signal from them. Ive ordered a low pass filter for 600 MHz and below, which should arrive in the next few weeks.

[GeorgeMx]

Originally Posted by GerryB

... Ive ordered a low pass filter for 600 MHz and below, which should arrive in the next few weeks.

Where did you order the filter and what did it cost, if you don't mind disclosing this information?

[GerryB]

http://www.***********/Channel-Plus-.../dp/B00006JPE6

Amazon actually distributes them. There was a Chinese manufacturer I was looking at for a while, but I lost contact with them (http://www.soontai.com/LPF.html). There was also this company: http://www.sadoun.com/Sat/Products/P...ss-Filter.html but they only have 550 MHz or 700 MHz, which wouldnt have a steep enough rolloff by 730 MHz.

I told the Chinese manufacturer I was getting into manufacturing of low noise preamps for the TV band and needed a very good 700 MHz block solution. If he comes through with a good price I might actually get into it. I work with a PCB manufacturer on lighting designs and he was very open to the idea of building preamps.

Cost from Amazon was $35

[morehp]

2 weeks and no reply.... I'd make contact with Rogers again or send the same email again and if they ignore you again and a week passes I'd contract a local tv news channel to see if they would be interested in running a story on it and see if they can get Rogers to comment on your concerns....

Wondering if the CBC show Market Place would/could be of help getting Rogers to respond... their show seems to favour the consumer and at least they might be able to get Rogers to respond to your complaints/concerns.

[GerryB]

Im not actually a consumer of any of Rogers products. I severed ties with them almost 5 years ago when I switched to Bell for DSL and OTA for television. In this case they are simply a bad neighbor interfering with (granted it is their own) broadcast television signals. My electronics devices that arent rigorously RF shielded have probably no rights.

The only other concern is the potential health risks, but real verifiable microwave sickness doesnt reliably kick in until about 10 dB to 15 dB higher than what I have here.

But then it does beg the question - if I operate a wireless phone near my head which is less than 1% less than the SAR (Specific Absorption Rate) limit of 1.6 watts / KG over 6 minutes - or whatever it is - and there are a few of them that literally JUST pass the test - then technically the level at my head could go as high as 10% above the safety limit for the time it is operating.

[GerryB]

Someone from Rogers called in response to the letter today and they are actually coming over on Tuesday.

Also, I got the filter in the mail a few days ago. Seems to work above channel 36 - just cuts it out entirely. Very sharp cutoff

[Jase88]

Someone from the cable division likely just sent you what they use to trap out channels for lower-tier customers.

[GerryB]

No they are actually 2 unrelated events. I ordered the filter a few weeks back - and it finally came. I think the person from Rogers is with wireless - but you gave me a good idea - they probably have good filters that cut off at 680 MHz instead of 600 MHz. I will ask.

[tvlurker]

I doubt it. Rogers in Ottawa traps cable channels 29 to 60, which is about 250 MHz to about 440 MHz. They probably have other traps, but I don't see why they would stock 680 MHz low pass filters.

[Trip]

Originally Posted by GerryB

Someone from Rogers called in response to the letter today and they are actually coming over on Tuesday.

Let us know what happens; I'm curious to find out what they say/do.

- Trip

[GerryB]

They definitely came and saw. I knew they were not used to it when one of them said "it's off the charts". They had a preamp on their spectrum analyser so they had to shut it off. It was one of those integrated spectrum analysers with a log-periodic antenna - the expensive kind.

They were super-courteous and knowledgeable, which was nice. Normally they look for interference into Rogers systems as opposed to the other way around.

When they shut down their systems temporarily, as expected, all the interference went away. I kept pointing out my main beef with the whole thing was the 700 MHz transmitter, which apparently is still just a set of carriers, which really worried me if they fire it up for real what it will do to the TV, being within the passband.