fcc – Engineering Radio

Saving AM radio

I am watching, with great interest, the hand-wringing over the removal of AM radio from various vehicles. Not that I desire that to happen, but on the current trajectory, it is almost certain that AM and then FM radio will become optional if not removed completely from dashboard entertainment systems.

What can be done… what can be done…

Interestingly, several have pointed to a few successful AM stations that are still making a go of it. WABC in New York is one such station. What is the difference between WABC and other stations? Local content, perhaps? Yes, WABC is a 50 KW clear channel (Class A) station. While that does help somewhat mitigate the electrical noise problem, in and of itself, being a 50 KW station does not automatically mean success. There are other 50 KW stations in the New York Market, they are not doing that well.

I would posit; what troubles AM radio and all of radio in general, is low-effort, low-quality programming, and a general lack of community engagement. The vast majority of AM stations are running some type of syndicated programming. That is not a huge issue provided there is local content mixed in, a local morning show for example. If everything is syndicated then what is compelling listeners to tune in? If I can get better information or more entertainment by listening to a podcast on Spotify or Substack, why would I listen to the radio at all? This is a growing problem for FM as well. All of the generic “Greatest mix of the 70s, 80s, and 90s” formats are dull and boring.

One reason for all the dullness is that shy corporate lawyers to are risk-averse and do not want to be sued for profanity. Remember the Janet Jackson Superbowl incident where CBS was fined $550,000 for briefly, very very briefly showing a nipple on TV? If you were blinking at the time, you would have missed it. I missed it. I am a first amendment guy, I have two words regarding the FCC obscenity rules; fuck that. The FCC should get rid of all the outdated and patronizing profanity regulations. They stifle free thought and they are not protecting anyone from anything. I have two children and they would come home from kindergarten swearing like drunken sailors. This is why podcasts are popular; hosts are allowed to roam freely express themselves, and explore controversial topics. You may not like what you hear, in fact, you may even be offended. However, there are no constitutional protections against being offended. All radios are equipped with tuning buttons and off buttons.

AM also suffers from a perception problem. When a station does show moderate success, it is still very difficult to sell advertising because the potential advertisers believe that no one listens to AM radio anymore. This is more a self-inflicted wound than anything else. For years, AM spots were bonused with an FM buy. If radio owner’s themselves don’t value their product, how can you expect advertisers to value it? Besides, I know lots of people listen to AM radio for one reason or another.

There are some technical aspects to this conversation as well. First and foremost, the AM noise problem is the biggest technical challenge for AM listeners. The use of FM translators to retransmit AM signals is more of a gimmick than some type of solution. Especially when the maximum power for a translator is 250 watts (many are licensed at much lower power levels). While the AM signals they are associated with are 1,000 watts, 5,000 watts, 10,000 watts, or even 50,000 watts. A translator can be significant in the case of an AM daytimer (class D station) after-sign-off. Otherwise, they do not offer too much else for the typical AM stations. Most other “technical improvement” initiatives from the AM revitalization era were more aligned with cost savings for owners rather than actual technical improvement.

One of the great advantages of AM radio is it can cover large distances with moderate amounts of power. Transmitters and receivers are relatively simple devices that can function without an internet connection. As I learned from my contacts in Ukraine, broadcast radio is often the communication line of last resort when the grid is down. FEMA has spent a good deal of money hardening AM radio facilities across the US to ensure that they will remain operational during a crisis.

Regarding the alleged sound quality issues; I notice the AM radio in my Subaru sounds pretty good even when listening to music. What is interesting to me, when I first land on an AM station, it sounds pretty narrow-banded audio-wise. After a few seconds, it opens up and I get much better-sounding audio. I am not sure if this is just some random radio software function or if the IF adjusts itself for wider audio when the signal strength is good. In either case, the AM radio in my car sounds much better than the previous cars I have owned.

It would be very interesting, at least for me, to see a head-to-head test of HD Radio MA-3 vs DRM30 vs Analog AM vs a 250-watt FM translator. More research and testing of all digital audio transmission on Medium Wave frequencies should be done.

In short, saving AM is going to be an uphill battle in both directions. It comes down to three basic things:

Programming
Perception
Imaginative innovation

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 reduce 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

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 manufacturer 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 nonsense)!

The NAB has come out with its 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 marketplace has changed radically over the last ten years. The introduction of online listening via Pandora seems to have created a 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 smartphone 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
Online listening uses data at a fast rate. According to Pandora, they stream at 64 kbps, or 0.480 megabytes per minute or 29 megabytes 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 online listening. Assuming that the smartphone 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 smartphone 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.

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 the 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 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 watts. 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 the 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 its 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 on this subject: Harmonic Convergence?

Update: The response from the WKZE attorney can be found here, including the above-mentioned actual measurements.