FCC ruling against "ND" FM for running a DA

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NECRAT
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FCC ruling against "ND" FM for running a DA

Post by NECRAT » Fri Apr 03, 2015 4:03 pm

http://licensing.fcc.gov/cgi-bin/prod/c ... r_id=57146


FCC ruled that KFWR's ERI antenna was "pattern optimized" in such a way that the gain along one part of the azimuth as being 4.386db, and the maximum field relative to be 1.657 @ 105° thus causing the signal to radiate in that direction, an ERP of 274.56kW (Vertical), instead of the licensed 100kW., and ordered the station to show cause why it shouldn't be forced to reduce the TPO from 25kW to 9.1kW.

A long but really interesting read.
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Re: FCC ruling against "ND" FM for running a DA

Post by w9wi » Fri Apr 03, 2015 8:09 pm

Indeed, it is! IIRC they found the ratio between the maximum radiation and the minimum was something like 19dB, which if I'm not mistaken is 4dB more than is permitted for a *directional* station.

While looking for something else I found http://transition.fcc.gov/eb/FieldNotic ... 096A1.html in which another Texas station decided to operate their main transmitter and their aux at the same time... carrying two different football games...
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Re: FCC ruling against "ND" FM for running a DA

Post by Deep Thought » Sat Apr 04, 2015 9:37 am

Ah yes, the little-known bit of Rules prohibiting intentionally directionalizing a nondirectional antenna. I know of another FM that buried a yagi in the middle of their three bay ND antenna and then tried to claim that it was a low power auxiliary, which might have gotten them past an inspection had the main actually been hooked up to a transmitter. :lol:
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Re: FCC ruling against "ND" FM for running a DA

Post by Shane » Sat Apr 04, 2015 7:09 pm

There's battles going on besides between the two stations: two different consultants coming down on the side of one or the other station and two different antenna manufacturers with Shively taking shots at ERI. And a difference of inches in mounting. Verrry interesting.
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Re: FCC ruling against "ND" FM for running a DA

Post by COMMENG » Mon May 25, 2015 9:05 pm

It appears that Goliath, at 1300 ft with a licensed ERP of 100kW, is about to get cut to his knees by David, operating on a 300 ft tower with 6kW ERP.

Yet, it appears Goliath thinks he can take liberties with his antenna design in an attempt to crush the "Davids" in his area.

Interesting!

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Re: FCC ruling against "ND" FM for running a DA

Post by w4cl » Fri May 29, 2015 9:01 am

I worked for an FM one time that had a brand new antenna optimized in one direction over a town because the new corporate DE didn't know that it was a hyphenated market and cut the other town out completely trying to stop interference to a sister station in the next market on the 1st adjacent from us, killing our ratings. Oh, and the station was licensed as a ND. No one realized that is what the corporate DE did until the ratings started coming in. He soon was no longer employed once the owner found out he could be fined for operating a DA FM when not licensed for a DA FM.

Fun times!

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Re: FCC ruling against "ND" FM for running a DA

Post by kkiddkkidd » Fri May 29, 2015 6:30 pm

Let's not confuse OPTIMIZE and DIRECTIONALIZE. All side mounted FM antenna's have some natural level of directionality.

I have antenna's "optimized" all the time by planning tower mounting locations and spacing to make sure that we don't put a natural minima over an important area. Adding parasitics to put more signal over an area of interest is a whole 'nother thing.

Certain situations in spacing and mounting location can create some pretty interesting pattern "anomalies". Like the figure-8 pattern (mostly V in one lobe and mostly H in the other) that we found at one of my clients. A previous owner had bought the cheapest antenna, cheapest mounting, NO range study and put it on the tower face at 90 degrees to the area of interest. The area of interest was in a deep natural minima of that mounting. After having the manufacture do a range study following the station sale, this was the most extreme case of pattern distortion that I have ever seen. The range operator even commented on it...

On the other hand, I know of at least 2 side mounted ND FM antennas that HAVE parasitics that were added in an attempt to make the pattern more circular. A panel antenna would have been a better choice but the cost was prohibitive at the time.

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Re: FCC ruling against "ND" FM for running a DA

Post by w4cl » Tue Sep 29, 2015 2:24 pm

Just catching up on this thread. The antenna was "directionalized" with parasitics that "optimized the signal over one town and cut the other town out completely. When an independent consulting engineer looked at the modeled pattern, (no one would listen to me, what did I know, I was just the local chief) the parasitics came off faster than a tsunami coming on shore and the pattern returned to normal and there was a help wanted sign on the corp chiefs office door.

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