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Old 2011-10-17, 06:41 PM   #61
KRToronto
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Default Toronto - Dundas and Sherbourne - constant helicopters disruption

Hello,

Is anyone experiencing complete disruption with the helicopters over the city (Toronto)?

I think it may be due to the Occupy Toronto demonstrations...but it is constant and rendering my TV blacked out or broken up for much of the afternoon and early evening as I write. This is so frustrating!!

thanks... don't know if anything can be done frankly!
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Old 2011-10-17, 07:35 PM   #62
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it's kinda like the chicken and the egg,
Can't really propose a solution, until you find the source.
But if ya can find the source, there may be no need for a solution
Cause if ya could find it, u'd eliminate it

Did it just start recently? Been kinda windy in the northeast lately.
Could it be Electrical powerlines blowin in the wind?
What happened when ya tried the kill all breakers except the one powering your TV tuner???


Recently I found a bad porcelain light fixture in my basement. Replaced it
because the pull chain switch was broken. Low and behold one of the wirenuts
had a loose wire, occassionally arcing. Fixing that didn't solve anything here,
but it certainly eliminated one potential source.
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Old 2011-10-17, 08:11 PM   #63
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Quote:
Did it just start recently? Been kinda windy in the northeast lately.
2 weeks ago about. It's not the forced air furnace and it's not the fridge.

I just noticed it on UHF. I have to do tests but my wife is recording 4 hours per day with the TiVo so I cannot do it in the evening.

Thanks for your info and I will report what I find.
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Old 2011-10-18, 02:22 AM   #64
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KRToronto, I live near a hospital which routinely has helicopters arriving and departing, often flying over my home. Can't say it's ever impacted my reception. Though these are medical helicopters, and not likely broadcasting TV signals like the ones near your home are.

I'm not aware of which frequencies are used by news helicopters to carry their TV signals, nor what sort of strength they operate at.

It's possible the frequencies are near those used for conventional television, and thus it's overloading your tuners. Perhaps someone that knows more about these systems aboard news helicopters can comment...
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Old 2011-10-18, 07:27 AM   #65
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^^^^
Remote links are on microwave bands. Take a look at the antenna on the mobile trucks the TV stations use.
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Old 2011-10-18, 07:50 AM   #66
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I think they may have some channels adjacent to some of the "AWS" Freqs. Pretty sure they do in the States at least.
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Old 2011-10-18, 09:05 AM   #67
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I noticed Pico Macom (True-Spec) makes a 5-700MHz In-Line Low Pass Filter (LPF-700). The specs say it passes 5~700MHz with less than 1.0dB loss and stops 800~1000MHz (and likely above) by more than 50dB. While not intended for OTA, it should work well to prevent other upper UHF broadcasts from overloading your system.
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Old 2011-10-18, 11:56 AM   #68
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I've recommended that PM LPF-700 several times to customers who've discovered a newly erected cellular installation causing overload of their pre-amps which had previously been working fine. It has worked very well for this purpose.

As more of the LTE/4G services come online in the 700 MHz band as carriers expand their offerings, I expect this to be an even more common occurrence.
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Old 2011-10-18, 01:40 PM   #69
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Thanks for the confirmation of its effectiveness ADTech. It would be nice if pre-amp manufacturers could build a similar 700MHz LPF into their pre-amps (with the ability to switch it out for those who still need to receive stations in the 700MHz band), not only to minimize connector loss, but to keep it in a weather proof enclosure (it looks reasonably weather resistant though).

This would be another benefit of having an antenna (especially Yagi) optimized for the reduced usable UHF band for TV.
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Old 2011-10-18, 01:48 PM   #70
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Jase88....Thank you for taking time to reply.

...seemed to only affect CTV CFTO 9-1

When these protests happen - like G 20 - the city sounds like a war zone overhead - constant low flying helicopters!

Cheers ...tonite they better not OCCUPY my TV show ;-)
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Old 2011-10-18, 03:50 PM   #71
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KRToronto, Filtering everything outside of the TV bands is probably your best bet. In Toronto, you don't use VHF-LO (Ch. 2-6) so I would start with a 174MHz high pass filter. The above mentioned 700MHz low pass filter would be my second step. A 216 - 470 MHz band trap would be the last step, but, depending on your setup, you may already effectively have that.
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Old 2011-10-18, 07:00 PM   #72
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Roger1818...Thank you also Roger!!

Will pass your sage advice on to the person in charge of the antenna (Landlord!)

Best Regards
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Old 2011-10-21, 08:21 PM   #73
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Exclamation Sources of "Unlicensed Device" interferences within the DTV spectrum!

Older Wireless unlicensed microphone systems could be a local interference issue:
Quote:
http://en.wikipedia.org/wiki/Wireles...h_and_Spectrum
Many older wireless microphone systems operate in the VHF part of the electromagnetic spectrum. Systems operating in this range are often crystal-controlled, and therefore operate on a single frequency. However, if this frequency is chosen properly, the system will be able to operate for years without any problems.

Most modern wireless microphone products operate in the UHF television band, however. In the United States, this band extends from 470 MHz to 698 MHz. In 2010 the Federal Communication Commission issued new regulations on the operations of TV-band devices.
New TV devices using 54 to 698 MHz white spaces:
Quote:
http://en.wikipedia.org/wiki/TV-band_device

TV band devices or TVBDs are new unlicensed radio frequency devices operating in the vacant channels or white spaces between US television channels in the range of 54 to 698 MHz. The rules defining these devices were announced on November 4, 2008, and published by the U.S. Federal Communications Commission (FCC) in a Second Report and Order on November 14, 2008. The rules were finalized in a Second Memorandum Opinion and Order on September 23, 2010. Much of the work behind the definition of these devices was done by the White Spaces Coalition.
Future DTV frequency application could make OTA interferences intolerable:
Quote:
http://en.wikipedia.org/wiki/White_space_%28radio%29

The White Spaces Coalition consists of eight large technology companies that planned to deliver high speed internet access beginning in February 2009 to United States consumers via existing "white space" in unused television frequencies between 54-698 MHz (TV Channels 2-51). The coalition expected speeds of 80 Mbps and above, and 400 to 800 Mbit/s for white space short-range networking.[9] The group includes Microsoft, Google, Dell, HP, Intel, Philips, Earthlink, and Samsung Electro-Mechanics.

The White Spaces Coalition was formed after the Senate set the date to cease analog broadcasts. It doesn't appear to have a website, but many of the companies involved in the White Spaces Coalition are also involved in the Wireless Innovation Alliance.

Google sponsored a campaign named Free the Airwaves with the purpose of switching over the white spaces that will be cleared up in 2009 by the DTV conversion process by the FCC and converted to an un-licensed spectrum that can be used by Wi-Fi devices.[10] The National Association of Broadcasters disapproves of the project because they claim that it would reduce the broadcast quality of their TV signals.[11]
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Old 2011-10-21, 10:09 PM   #74
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Default Modern Wireless Microphone Frequencies

http://www.ic.gc.ca/eic/site/smt-gst...g/sf09777.html

A comment on wireless microphone frequencies:

Our church meeting hall just had to replace a recently bought microphone system because of the above frequency mandated changes. Our system operated on one of the frequencies between 698-806 MHz, also known as the 700 MHz band. Industry Canada has allocated the 700 MHz frequency band for use by public emergency services and commercial wireless services.

Although we never had complaints of causing any kind of interference, we felt it prudent to be compliant. I wonder how many other institutions or citizens even know these new guidelines exist.
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Old 2011-10-21, 10:35 PM   #75
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Shure has some helpful info


Wireless Spectrum Issues
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