The side mounted FM antenna

In an interesting development, the FCC has taken notice of some pattern distortion from the side mounted FM antenna of KFWR, Jacksboro, Texas.  For those, like myself, not familiar with Texas Radio, that is in the Dallas/Fort Worth market.  The crux of the issue is co-channel interference to KCKL in Malakoff, Texas.  These two locations meet the spacing requirements in 73.207 (215 km).  The issue is with the side mounted ERI antenna and what appears to be intentional pattern optimization.

From the FCC order to show cause:

ERI’s president, Mr. Thomas Silliman, acknowledging that KFWR’s antenna “was mounted in a favorable direction, but… has not been directionalized and therefore is legal.” Mr. Silliman adds that the custom lambda tower at the top of the new KFWR tower was specifically designed for operation at KFWR’s frequency of 95.9 MHz, and that the tower’s lattice structure is “repetitive at the half wave of the specified FM frequency.” Thus, “if one picks a favorable mounting position on the tower, every element in the array sees the same favorable mounting result. Mr. Silliman also states that vertical parasitic elements are used to make the vertical radiation pattern “more circular” and reduce the vertically polarized gain to the east. In a subsequent pleading, ERI elaborates that its computed values “are relative to an RMS measured field of 1.0.” Mr. Silliman concedes that the mounting of the antenna on a certain tower face constitutes “pattern optimization,”arguing later that this is a common practice used by all antenna manufacturers, but states that it is the ERI’s policy “not [to] increase the directivity of the antenna pattern.”

The FCC concludes that the directionality of the side mounted antenna, in this case, is clearly intentional. The radiated power towards co-channel KCKL was calculated to be 274.5 KW, which is in excess of the 100 KW limit and orders KFWR to reduced TPO from 25 KW to 9.1 KW.

We have lots of these out in the field:

Side-mounted Shively 6810 antenna.  WSPK, Mount Beacon, NY
Side-mounted Shively 6810 antenna. WSPK, Mount Beacon, NY

In fact, I believe the majority of our FM stations use side mounted antennas.  Some of them are mounted to a leg and some are mounted to a face.  Usually, I try to place the antenna on the tower so that the bays are facing the desired audience.  This information is given to the manufacture when ordering the antenna so that proper mounts can be furnished and the mounting distance between the tower and antenna properly calculated.  That is about the extent of any “optimization” that is allowed.

As the FM band gets jam packed with FM signals, this may become more of an issue in the future, particularly around dense signal areas around major metropolitan areas.

Fewer owners means more diversity!

Alternate title: Less is more (and other non-sense)!

The NAB has come out with their latest interesting opinion on radio station ownership in comments to the FCC regarding the 2014 Quadrennial Regulatory Review.  They state that “Retaining the local radio ownership rule unchanged would be arbitrary and capricious” because the audio market place has changed radically over the last ten years.  The introduction of online listening via Pandora seems to have created competition that can only be adequately dealt with by further consolidation, it seems.  Also, the Commission cannot demonstrate that the current rules promote localism or viewpoint diversity.  That last sentence is a fair statement.  What the NAB does not say is that there is no evidence that further consolidation will promote localism or viewpoint diversity either.

The comment then goes into a lot of information and statistics on smart phone usage; who has them, what they are using them for et cetera.  It is very interesting to note that there is no reason given for the sudden and alarming upswing in mobile online listening.  But, let us examine a few interesting data points first:

  • Mobile data is not free.  There are very few unlimited mobile data plans out there anymore, most everyone now has some sort of data cap.  Extra data can be purchased, but it is expensive
  • On line listening uses data at a fast rate.  According to Pandora, they stream at 64 kbps, or 0.480 megabytes per minute or 29 mega bytes per hour.   Spotify uses quite a bit more, 54 megabytes per hour.

Let us assume that the average commute to work these days is one hour.  That would mean two hours per day of driving and mobile listening.  That adds up to 1.16 GB of data per month just in on line listening.  Assuming that the smart phone functions as more than just a radio and will be used for email, maps, news, web browsing and other downloads, a fairly hefty data plan would be required of the smart phone user to accommodate all this data.  Why would somebody pay considerably extra per month just to listen to online radio?

Do you get where I am going with this?  Good, compelling programming is what people are searching for.  If they cannot find it on the radio, they will go elsewhere.  Nature abhors a vacuum.  Want to compete against Pandora, Spotify, XM or whoever?  Offer up something good to listen to.  These days, competition seems to be a dirty word.  Yes, competition requires work, but it, in and of itself, is not bad.

The NAB seems to be saying that relaxing ownership rules and thus, presumably, allowing more consolidation will promote diversity.  In my twenty five years of broadcasting, I can say that I have never seen this to be the case.   Some of the most diverse radio stations to be heard are often single stations, sometimes an AM/FM combo, just out there doing their thing.  Stations like WDST, WHVW, WKZE, WHDD, WJFF, WTBQ, WSBS, WNAW… I am sure that I am forgetting a few.

You can read the entirety of the NAB’s comments here.

Et tu, Massachusetts?

The Massachusetts house is considering a bill to outlaw unauthorized transmission in the AM and FM broadcast band. The bill, H.1679 is included here for your reading pleasure:

SECTION 1: The General Laws, as appearing in the 2010 Official Edition, is hereby amended by inserting after chapter 93I, the following chapter:-

Chapter 93J. UNAUTHORIZED RADIO TELECOMMUNICATION

Section 1. As used in this chapter the following words shall, unless the context clearly requires otherwise, have the following meanings:—

“Emission”, radiation produced, or the production of radiation, by a radio transmitting station.

“License”, a radio frequency assigned by the Federal Communications Commission for use by amplitude modulation (AM) radio stations between the frequencies of five hundred thirty kilohertz (kHz) to seventeen hundred kilohertz (kHz), or frequency modulation (FM) radio stations between the frequencies of eighty-eight megahertz (MHz) to one hundred eight megahertz (MHz).

“Person”, a natural person, corporation, association, partnership or other legal entity.

“Radio telecommunication”, any transmission, emission or reception of signals and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems

Section 2. Any unauthorized radio telecommunication or emission to, or interference with, a public or commercial radio station licensed by the Federal Communications Commission are prohibited.

No person shall (a) make, or cause to be made, a radio telecommunication in the Commonwealth unless the person obtains a license or an exemption from licensure from the Federal Communications Commission under 47 U.S.C. s. 301, 47 U.S.C., s. 605, or other applicable federal law or regulation; or (b) do any act, whether direct or indirect, to cause an unlicensed radio telecommunication to, or inference with, a public or commercial radio station licensed by the Federal Communications Commission or to enable the radio telecommunication or interference to occur.

Section 3. The attorney general may bring an action pursuant to section 4 of chapter 93A against a person or otherwise to remedy violations of this chapter and for other relief that may be appropriate.

Section 4. A person may assert a claim under this section in superior court, whether by way of original complaint, counterclaim, cross-claim or third-party action, for money damages, injunctive relief, and forfeiture of any property used in violation of this section. Said damages may include double or treble damages and attorneys’ fees and costs.

No forfeiture under this section shall extinguish a perfected security interest held by a creditor in a conveyance or in any real property or in any personal property at the time of the filing of the forfeiture action. Said forfeiture action shall be commenced in superior court.

This legislation is slightly different from the anti-pirate laws in NY and Florida as it appears the unauthorized operators would be liable for civil and not criminal penalties.  That is an interesting twist; potentially, a commercial broadcaster could sue an interfering pirate operator for loss of revenue, etc.  At least that is my interpretation of the above text and as I am not an attorney, I could be wrong.

It is also interesting to me that very few pirate operators in NY have actually faced a non-FCC law enforcement agency as of yet.  I have heard about only one, which was in NYC.  Is the criminalization of unauthorized broadcaster really affective in curbing pirates?  A quick tune around the NYC FM dial says no.  There are more pirates than ever and the NYPD seems to be too busy with other issues to go after them.

The curious case of the WKZE Notice Of Violation

On June 19th, WKZE received a notice of violation from the FCC’s New York Field office.  The crux of the issue seems to be interference being generated on 784.8 MHz (WKZE 8th harmonic) to a new Verizon Wireless installation located nearby:

47 C.F.R. §73.317(a): “FM broadcast stations employing transmitters authorized after January 1, 1960, must maintain the bandwidth occupied by their emissions in accordance with the specification detailed below. FM broadcast stations employing transmitters installed or type accepted before January 1, 1960, must achieve the highest degree of compliance with these specifications practicable with their existing equipment. In either case, should harmful interference to other authorized stations occur, the licensee shall correct the problem promptly or cease operation.” The eighth harmonic of Station WKZE-FM (784.8 MHz) was causing interference to the Verizon Wireless transmitter located approximately 500 feet away.

First off, we note that the WKZE transmitter is not allegedly causing interference to a Verizon Wireless transmitter, but rather to a Verizon Wireless receiver.  That may be splitting hairs, however, since the FCC is quoting a technical rules violation, they can at least get the technical language right.

A brief examination of rest of FCC part 73.317 is in order to find the specification cited in section (a).  Section (d) states:

 (d) Any emission appearing on a frequency removed from the carrier by more than 600 kHz must be attenuated at least 43 + 10 Log10 (Power, in watts) dB below the level of the unmodulated carrier, or 80 dB, whichever is the lesser attenuation.

Since 784.8 MHz – 98.1 MHz is greater than 600 KHz, this is the section that applies to the WKZE situation.  Thus, the interfering signal must be greater than -80 dBc to trigger the Notice Of Violation (NOV) from the FCC.  The station ERP is 1,800 watts or +62 dBm.  Measurements were made with a an Agilent N992A spectrum analyzer using an LPA-1000 log periodic antenna.  At a 12 foot distance away from the WKZE transmitter cabinet, the signal on 784.8 MHz was found to be -94 dBc or 0.000063 watt.  At the base of the Verizon Wireless tower, the measurement was -124 dBc, or 0.000000025 watt, which is barely perceptible above the -130 dBm noise floor.  There does not appear to be any violation of 47 CFR 73.317.  Rather, the issue seems to be Verizon Wireless’s deployment of 700 MHz LTE band and the use of high gain antennas coupled with high gain preamplifiers on frequencies that are harmonically related to broadcast stations nearby.  In this particular installation, the antenna has 16 dB of gain, minus a 4.5 dB of transmission line loss into a 21 dB preamplifier before the receiver.  At the output of the Verizon preamplifier, the signal on 784.8 MHz was measured at -89 dBc, which is still in compliance.

By these measurements, clearly WKZE is not in violation of any FCC regulation.  It makes one wonder, does the FCC understand it’s own rules?  Or, is this a matter of favoritism towards a huge corporation over a small independent radio broadcaster.  Is it a matter of “broadband at the expense of all others?”  There are several of these broadcast to 700 MHZ LTE interference cases pending throughout the country.  This could set a dangerous precedent for broadcasters and other RF spectrum users as wireless giants like Verizon throw their weight around and eye even more spectrum to press into broadband service.

Commlaw blog has a good post this subject: Harmonic Convergence?

Update: Response from WKZE attorney can be found here, includes the above mentioned actual measurements.