Severe OTA Interference From New Digital Services Tower - Page 6 - Canadian TV, Computing and Home Theatre Forums

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post #76 of 149 (permalink) Old 2011-02-19, 12:49 PM
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I dont understand why Industry Canada would not make Rogers wait until August .

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post #77 of 149 (permalink) Old 2011-02-19, 01:10 PM
 
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Since Rogers is the only broadcaster in Ottawa on channels 52+, maybe they were able to waive their protection and accept the interference from their wireless division.
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post #78 of 149 (permalink) Old 2011-02-19, 01:21 PM
 
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Quote:
Originally Posted by majortom View Post
GeorgeMx,

I agree any communication with the suspect operator, Rogers, should be civil, etc. But if your insinuating that every form of consumer electronics known to man should have a Faraday Shield around it in order to function properly to accomodate Wireless operators all over the world, I think that's just going a little overboard.
Just face it, in a cellular system, they have no real need to be transmitting 1000 W ERP for any technology, anywhere. Much less in the city.
I am not suggesting anything like that - I live in the real world. Consumer electronics manufacturers should build designs with sufficient protection to keep RF out of the circuitry. In many cases they simply require a bypass capacitor to short RF to ground.

The ERP for a transmitter is not an arbitrary decision, it is based on signal level calculations. Customers want these high data rates into tiny devices with miserable antennas. The only way to achieve results requires bandwidth and power. Shannon's theorem provides the underlying physics of the communications channel - the actual implementation will require more power.
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post #79 of 149 (permalink) Old 2011-02-19, 01:59 PM
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GerryB mentioned that his telephone was picking up the interference too. I know that telephones in Canada require IC certification, but I take it that approval covers the telephone's own emissions and not it's shielding. Anyone know for sure?
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post #80 of 149 (permalink) Old 2011-02-19, 02:26 PM
 
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Originally Posted by GerryB View Post
Hi GeorgeMX

I dont disagree with anything you are saying. I calculated the 17 dB below safety code 6. ... I havent sent anything to the media, but I am seriously creeped out that I can light up a lamp with the radio energy coming through my window. ...
I respect your personal concern about RF exposure but you might think about the amount of power involved. LEDs don't require much power to light so making one flicker from ambient RF might not mean much. To put the observation into context, how big would a 30% efficient solar cell have to be to light the same LED in the same way? A couple of square centimeters? I make the comparison because the power density in sunlight is really low.
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post #81 of 149 (permalink) Old 2011-02-19, 02:29 PM
 
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Stampeder, I recall the IC certification deals with the telephone not causing any risk to the telephone network. The FCC and IC don't care how well the phone works as long as it doesn't screw up the public network.
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post #82 of 149 (permalink) Old 2011-02-19, 02:35 PM Thread Starter
 
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Sent to: OfficeOfThePresident@rci.rogers.com

Quote:
Please direct to Wireless Engineering

Dear Sir or Madam,

I am writing to seek your help in a case of radio interference that is so strong that I can "light up a lamp" in my apartment with the radio energy from what I believe is your PCS and LTE base station. I live at 169 Lees Avenue on the top floor facing southeast, toward a building that is 68 meters away, 180 Lees Avenue, on which you have newly licensed approximately 4000 watts ERP of combined PCS 1.8 GHz, cellular 800 MHz, and new experimental LTE 700 MHz base station power directed at my apartment, at an azimuth of 290 degrees. The tilt angle also appears to be pointed directly at my apartment.

The types of interference I am experiencing are myriad - my Yamaha professional electronic piano makes a very high pitched loud ringing sound when I turn it on, worse depending on how it is oriented. My landline telephone makes the same sound. My television set, to which I have connected rabbit ears to receive over-the-air channels, has distracting thick horizontal lines in the UHF band on stations (to which I have line-of-sight) that were otherwise so strong I could pick them up with a paperclip before. Channel 60, Omni1 Television, is particularly affected.

As an experiment, I connected a small LED lamp to an inductor coil, a diode, and a piece of 6 inches of wire (similar to a classic crystal radio set). No batteries. I held this by the window, and it lit up brightly on and off, which I assume corresponds to your transmitter periodically linking up to cellphones, etc. I note that the power level for Safety Code 6 is 4 watts/ meter squared at low UHF frequencies. I calculated that, if the licenses below are in fact in operation, the level here would be within about 17 dB of safety code 6 but not over and therefore compliant with Canadian levels. Here is a photo of the antenna ( http://s214.photobucket.com/albums/c...estations2.jpg ), a photo of the best reception I could get on channel 60 ( http://s214.photobucket.com/albums/c...gs12/intf3.jpg ), a sample of the noise emitted by my piano ( http://s214.photobucket.com/albums/c...terference.mp4 ), and finally the LED powered by, to my best guess, your radio waves ( http://s214.photobucket.com/albums/c...crowaveLED.mp4 ).

Below is some of the information I have compiled on the licenses of these stations from the publicly available Spectrum Direct website offered by Industry Canada that, if you are interested in helping me resolve this interference, may be useful to you. There are other Rogers PCS stations on the building with many more thousands of watts ERP, but pointed elsewhere.


TX Frequency 734 MHz
Callsign VX9FIT
License Number 5110000
ERP 1,202 watts
Azimuth 360 degrees
Location 180 Lees Avenue


TX Frequency 1970 MHz
Callsign SITE575233
License Number 1382963
ERP Power 955 watts
Azimuth 290.0
Location 180 Lees Avenue

TX Frequency 1930 MHz
Callsign SITE575233
License Number 1382963
ERP Power 955 watts
Azimuth 290.0
Location 180 Lees Avenue


TX Frequency 869 MHz
Callsign SITE575233
License Number 1382963
ERP Power 602 watts
Azimuth 290.0
Location 180 Lees Avenue


I have contacted an online community of radio frequency experts with whom I normally discuss over-the-air television and the new HDTV. They have suggested that I contact you directly (I tried this once at the very start a few weeks ago but the people who answered the phone had no idea what I was talking about). I also tried contacting Industry Canada's district office, who told me they do not deal with interference complaints from the public.

Thanks in advance for any help you could offer, such as possibly raising the antennas on tall masts so the main beam is not pointed in mine and my neighbours' front windows.

Respectfully Yours,
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post #83 of 149 (permalink) Old 2011-02-19, 02:48 PM
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Quote:
But if your insinuating that every form of consumer electronics known to man should have a Faraday Shield around it in order to function properly to accomodate Wireless operators all over the world, I think that's just going a little overboard.
Not a Faraday shield, but properly engineered. Many companies cut costs by scrimping on shielding, bypassing etc. As mentioned, this has long been a problem for many services. It is not the responsibility of the radio service when this happens, as it's due to a defect in the device being interfered with, at least with non-radio devices, such as that piano etc. Also, many radio services are licenced for a lot of power and some of them are close to residential areas. For example, there are condos almost directly under the CN Tower, where there's a *LOT* of power broadcast. Also, amateur radio operators are licenced for up to 1 KW and many of them live in residential areas. If a ham living next door gets into your audio equipment, then it's your problem and not his, as audio gear should not be responding to RF. If interfering with radio or TV, then it's his responsibility to ensure his signal is clean, but once he's done that, it's your problem again. ISM band equipment, such as WiFi, cordless phones etc. get absolutely no protection from and must not interfere with licenced services. So, if your WiFi is interfereing with the ham next door, who's operating on the band that overlaps WiFi, then it's again your problem to resolve.

Quote:
but I take it that approval covers the telephone's own emissions and not it's shielding. Anyone know for sure?
That's certification for connection to the phone network, but there's also laws regarding emmisions that all electronic devices have to comply with.

Meanwhile, back at the ranch...
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post #84 of 149 (permalink) Old 2011-02-19, 02:57 PM
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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.
Noone designs anything waterproof either. Why? because it's not meant to get wet in normal operation.
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post #85 of 149 (permalink) Old 2011-02-19, 03:00 PM
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^^^^
So, you're expecting licenced radio services to change their operation because they're interfering with some crappy equipment????

Meanwhile, back at the ranch...
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post #86 of 149 (permalink) Old 2011-02-19, 03:04 PM Thread Starter
 
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>>To put the observation into context, how big would a 30% efficient solar cell have to be to light the same LED in the same way? A couple of square centimeters? I make the comparison because the power density in sunlight is really low.

The solar cell would have to be about 3 times the size of the LED assuming the LED has the same brightness flux as the sun. The sun puts out up to 100 watts per square foot at the equator at noon. We're talking apples and oranges here. The point is they are much different frequencies.
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post #87 of 149 (permalink) Old 2011-02-19, 03:07 PM
 
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Originally Posted by ralph_sinclair View Post
Since Rogers is the only broadcaster in Ottawa on channels 52+, maybe they were able to waive their protection and accept the interference from their wireless division.
Broadcasters can agree to accept interference into their own services. For example, Rogers OMNI uses channel 69 in Toronto and London, and has interference in the zone between the two transmitters.

IC may not have been overly concerned about interference between the TV and the experimental use of spectrum. The Rogers Wireless experimental transmitter is low power and low height compared with typical broadcast transmitters so any interference would be restricted to a very small geographical area. If you consider the high level of BDU usage in cities and the small area of potential interference, the number of TV viewers affected is not very big. In any case, the same problems would be evident when the wireless companies started to use the frequencies above channel 51 after the August 31, 2011 shutdown.

To IC, which is concerned with making use of spectrum for the benefit of Canadians, allowing Rogers to get on with testing now versus the possibility of interference to a few OTA viewers is an easy decision. If nothing else, IC can now anticipate problems for OTA viewers when the wireless companies occupy the bandwidth above channel 51. The wireless companies and IC should probably ensure that low pass filters are available in the marketplace for OTA viewers experiencing problems.
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post #88 of 149 (permalink) Old 2011-02-19, 03:12 PM
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So, you're expecting licenced radio services to change their operation because they're interfering with some crappy equipment????
No, not at all, I'm saying any licensed operator is expected to always use the bare minimum to get the job done, and to be responsible, not wreckless. It's a pretty basic concept of wireless system design. Many small low power cells, are always preferred over a small number of high power cells.
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post #89 of 149 (permalink) Old 2011-02-19, 03:14 PM Thread Starter
 
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>>If a ham living next door gets into your audio equipment, then it's your problem and not his, as audio gear should not be responding to RF

JamesK this is totally different. Ham operators dont operate 24 hours a day 7 days a week, and they raise their antennas above the rooftops when they transmit 1000 watts ERP. Also they are limited to 1000 watts ERP not 4000 watts ERP. And a lot of the time they transmit that high power on frequencies that can be fixed by using a common mode choke. IVE DONE THAT. I can show pictures of how Ive shielded AND put a choke coil on my phone and I can tell you they dont work. This isnt the shortwave band.

As for the CN tower, those people live UNDER the antenna which is wayyyy up a good 400 meters above the nearest residential spot. Even if they transmit 10 million watts ERP up there the beam focus might be at best giving 20 kilowatts ERP straight down in a side lobe. But that's 400 meters away so yeah it is the equivalent of about 600 watts ERP at 70 meters by the R squared rule. Not 4000 watts. And those people have cement roofs blocking by 10 dB or more attenuation - so really more like 60 watts ERP at 70 meters. Their windows dont face the transmitter directly.
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post #90 of 149 (permalink) Old 2011-02-19, 03:16 PM
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The picture being painted here is that big cellular businesses have been handed a license to expand their high profit portfolios at the expense of antiquated equipment and at the unknown risks to human health. That does not surprise me! If I was knowing that I was being exposed to enough radiated power to light even one-half of a LED bulb, I would not spend another night in that environment. And that comparison that someone made being no worse than sunlight is bogus in my opinion, being that humans are not created with solar panels. Any level of prolonged exposure to ionizing or non-ionizing radiation is overexposure.

Quote:
Cell phones and cell phone towers
Cell phones and cell phone towers use radiofrequency and low-level microwave radiation to transmit and receive signals. Neither cell phones nor cell towers have been conclusively linked to increased risks of cancer, but most researchers and government agencies agree that more research on cell phones is needed, especially with regard to long-term use and use among children. For more detailed information, refer to our documents, Cellular Phones and Cellular Phone Towers.

http://www.cancer.org/cancer/cancerc...ure-and-cancer
So, as it stands, humans are being put a risk of the un-proven risk!

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Last edited by ota_canuck; 2011-02-19 at 03:38 PM. Reason: I hope you don't have a pacemaker!
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