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Author Topic: 911 interference caused by wind turbines  (Read 1523 times)

K2HRO

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911 interference caused by wind turbines
« on: July 22, 2019, 06:52:18 PM »

My town is considering a wind farm. Two 500' turbines will be 450' the county 911 ~6 GHZ microwave path. I told the county they are nuts but I don't think they are taking it seriously.

Does anyone out there have any horror stories that would help make my case.

thanks
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KB8VUL

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RE: 911 interference caused by wind turbines
« Reply #1 on: July 22, 2019, 10:10:12 PM »

Sometimes people need to find out the hard way that things like this can occur. 
If the poles are in direct path, they will get some signal attenuation.  But if it's only the rotor blades, it's gonna depend on the makeup of the blades as to how bad the fading may or may not be.
As far as them not taking you seriously, that's pretty common.  The authority of the jurisdiction only see's dollar signs in tax money when it comes to stuff like this.  And it's that mind set that gets you crap like buildings that look like baskets.  Look that now abandon building up on google for a few laughs. 

But on a side note, hope that you are right. 
If you are right and there is a problem, the next time up comment, they MAY listen.
IF you are wrong... You become Chicken Little, and you will never be given any credit for anything ever again.
 
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AC7CW

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RE: 911 interference caused by wind turbines
« Reply #2 on: July 23, 2019, 05:55:51 AM »

Government is 99% reactionary and 1% proactive. I'd wait until it doesn't work then enjoy the show while they try to deny the problem exists, use the problem to raise taxes, etc...
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Novice 1958, 20WPM Extra now... (and get off my lawn)

W1VT

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RE: 911 interference caused by wind turbines
« Reply #3 on: July 23, 2019, 08:33:00 AM »

https://www.telegram.com/news/20171223/turbines-blow-hot-cold-on-financial-benefits-for-local-towns
This article has a map of wind farms in New England that may assist your research.
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WB3DYE

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RE: 911 interference caused by wind turbines
« Reply #4 on: July 25, 2019, 08:22:00 PM »


You talk abt warning the communities about the bad effects,especially at microwave.

Heres a story which is similar. The Pa State Police decided on a new radio system. Trunked at 800 mhz. I'm a ham operator and a retired TV journalist. At the time when they started to deploy it I was in TV and interviewed the project manager who is also  a ham. I told him that was the rugged mountains and deep valleys in Pennsylvania the 800 MHz  system  would have MAJOR holes and it wouldn't work. In a nice way  he told me I didn't know what I was talking about--

Fast forward to 2019---I WAS RIGHT!!!--THEY ARE TAKING THE 800 MHZ SYSTEM APART!!!!!!!!!!! I should mention it's now nearly a BILLION dollars over budget.   For nearly a year the State Auditor General (the elected taxpayers watchdog) has been looking at the system.
The state is now spending 44 million dollars more to deploy another trunked system this time VHF.

Here are links from the Auditor General and  the State Police Major who testified before a joint Senate and House Committee.

https://www.paauditor.gov/press-releases/auditor-general-depasquale-launches-review-of-statewide-radio-network

https://www.abc27.com/investigators/investigations/statewide-radio-a-nearly-billion-dollar-boondoggle/

http://pasenategop.com/communications/wp-content/uploads/sites/47/2018/03/stackhouse.pdf

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W1BR

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RE: 911 interference caused by wind turbines
« Reply #5 on: July 26, 2019, 11:01:51 AM »

Connecticut State police did the same nonsense a few decades back... gave up the low band VHF system which worked quite well into valleys and mountainous areas for a trunked 800 MHz system.  At first it was worst than the original system.  I am sure they kept throwing money at until they filled the holes.
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N7LJC

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RE: 911 interference caused by wind turbines
« Reply #6 on: August 25, 2019, 04:55:27 PM »

Connecticut State police did the same nonsense a few decades back... gave up the low band VHF system which worked quite well into valleys and mountainous areas for a trunked 800 MHz system.  At first it was worst than the original system.  I am sure they kept throwing money at until they filled the holes.

I wonder if they gave up their low-band VHF licenses.  (Though I don't know if anyone makes low-band equipment anymore...)
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W9IQ

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RE: 911 interference caused by wind turbines
« Reply #7 on: August 26, 2019, 03:46:13 AM »

Missouri State Troopers still have low band VHF installed in their vehicles. They recently upgraded the tube based linear at the regional HQ near me to solid state. I believe it is 500 watts output.

- Glenn W9IQ
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- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

WA2ISE

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RE: 911 interference caused by wind turbines
« Reply #8 on: September 01, 2019, 07:31:18 PM »

Take a look at https://en.wikipedia.org/wiki/Fresnel_zone about Fresnel zones in microwave links.  If the wind turbines intrude into your 911 links' fresnel zones, the moving turbine blades could goof things up enough to cripple the link.  As reflections off the blades are constantly changing, and most ghost or reflection cancellation schemes expect the reflections to not change much. 

They might be able to deal with this if they use pair of microwave transcievers of sorts mounted on one of the turbine towers.  It would receive the 911 signal from the original source on a channel A, and feed it via an ethernet cable or such to another transciever running on a channel B and transmit it, aimed at the original destination.  This would keep the rotating blades out of the fresnel zones.
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ND5Y

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RE: 911 interference caused by wind turbines
« Reply #9 on: September 08, 2019, 12:38:25 PM »

Kenwood still makes low band radios.

The Missouri State Highway Patrol is authorized up to 5 kW output/15 kW ERP at their high power low band sites.
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Tom

KB8VUL

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RE: 911 interference caused by wind turbines
« Reply #10 on: September 09, 2019, 07:21:02 PM »

OK, that was the OP's first and only post.  We have never heard anything else about this matter.  And while we can sit here and high-jack the thread and discuss microwave propagation, Fresnel windows, path loss, and mechanical reflection of link paths due to wind turbines, airplanes, helicopters, and flocks of birds wearing tin foil hats, I believe the matter of the OP to be closed.
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