The late 1980s were a turning point for AM radio in the US, as music gave way to the rise of talk. By the 1990s most of the music on the AM dial was limited to old time country and easy listening; essentially music favored by truckers, in the case of the former, and senior citizens, in the case of the latter. But the exodus of most music programming to the FM dial also meant that AM stations became a lot cheaper to program or buy time on. Thus the AM dial also became home to music and formats that you wouldn’t find on FM.

In 1991 Tucson, Arizona’s AM dial became home to the city’s first hip-hop station, Power 1490. The station was significant because hip-hop and rap music still were a few years away from wide mainstream pop acceptance. While there had been some crossover pop hits in the 80s, stations specializing in hip-hop were still hard to find outside the country’s largest markets.

A new documentary about Power 1490, A.M. Mayhem, debuts this weekend in Tucson. According to the film’s website,

From its inception and debut year on the air, to the height of its success, to the station’s demise and format flip–that until now had gone unexplained–A.M. Mayhem addresses all the unanswered questions and dives into the juicy details of one special A.M. radio station that brought Hip-Hop to the desert-town of Tucson, Arizona, when no one else would.

Tickets are free and require making an RSVP at the website. Apparently, this will the only public screening of the film. Afterwards the film will only be available on DVD.

Here’s the trailer for the film, followed by an aircheck of a drive-time show recorded in 1992.

Packing Up Radio History (Photo Taken at KUSF by J. Waits)

I know a lot of people who would love to have a terrestrial broadcasting license, so it seemed odd to me when I read about a Chattanooga radio station turning its license back to the FCC. Why on earth would a station opt to dispense with their license when there are so many entities out there who are desperate to get on the air or expand the range of their existing networks?

Well, WDOD-AM did just that. The 86-year-old station (yes, you read that right!) turned off its transmitter on May 31 and disposed of its license with the FCC on June 3. The FCC database lists the license for WDOD as “cancelled.”

Apparently the license was not valuable enough to sell, but the land was. According to an article in the Chattanoogan, the owners of WDOD sold the 22-acre property where the transmitter was housed to the Baylor School for $600,000. The article states:

“The former station building at the property had not been used except as a transmitter since around 1999 when [former station owner Cy] Bahakel also bought WDEF AM. Bahakel moved the station for WDOD and WDEF AM to the former Chattanooga Hardware on South Broad Street.

Mr. Freudenberg, who was at WDOD for four decades, recalled, ‘WDOD is rich in history going on the air April 13, 1925. Co-owners Norman Thomas and Earl Winger had a crystal radio company. Mr. Thomas told me they got the radio station license so folks who bought the radios would have something to listen to. Mr. Thomas said they got mail from as far away as Australia. I have a lengthy interview with him on tape. The station was very special to me since I spent about 40 years working there. It’s a sad day for Chattanooga radio but I realize that good memories and nostalgia don’t pay the bills.’

Mr. Winger and Mr. Thomas sold the station to H. Clay Evans and Interstate insurance in the late 50s. The Bahakals bought it in 1963. The station maintained its original call letters for its entire life. Mr. Freudenber said Cy N. Bahakal told him one time he would never sell the station, but he died several years ago and the station passed to his family.”

I was surprised by this story and wonder if any attempt was made to sell the license and transmitter to another entity, thinking of course that there must be other broadcasters out there desperate for a license. I also started to wonder how often stations end up turning their licenses back in to the FCC. In my research I found rumors that a San Francisco Bay Area commercial radio station, KTRB-AM (Xtra Sports 860), may be on the verge of doing just that. The station, which is currently owned by Comerica Bank, is apparently up for sale. An attempt to sell the station to the Oakland A’s baseball team fell through and the station appears to be struggling. Back in October 2010, KTRB’s receiver asked the FCC for Special Temporary Authority (STA) to operate the station at reduced power at night (which was granted). In November, 2010 a second request was made to the FCC, asking for permission to cease nighttime operation of the station. According to that filing:

“THE RECEIVER OF STATION KTRB IS IN THE PROCESS OF ATTEMPTING TO SELL THE STATION OR TO FIND AN ACCEPTABLE TIME BROKER TO PROVIDE PROGRAMMING FOR THE STATION. DURING SUCH EFFORTS, INSUFFICIENT FUNDS ARE AVAILABLE TO OPERATE THE STATION ON AN UNLIMITED BASIS, AS AUTHORIZED BY THE KTRB LICENSE. AS A RESULT, THE RECEIVER HEREBY SEEKS AUTHORIZATION TO CEASE NIGHT TIME OPERATION ON THE STATION UNTIL SUCH TIME AS A PROGRAMMER OR AN AGREEMENT TO PURCHASE THE STATION IS FINALIZED. THE STATION CEASED OPERATING DURING NIGHTTIME HOURS WITH NIGHT TIME FACILITY ON OCTOBER 15, 2010.”

The authority that the FCC granted for reduced power at KTRB expired on April 20, 2011 and the rumor mill is speculating that the license could get turned back to the FCC. Since it’s a San Francisco Bay Area station, I immediately starting wondering if this license could be available for use by KUSF. When I asked Common Frequency’s Todd Urick about this he told me:

“The net worth of any AM license nowadays is more complicated to derive.  The situation with KTRB is a quagmire.  KTRB is owned by the bank, and has separate day and night directional towers at completely different sites.  I heard the night site doesn’t have power.  On one side, the station coverage is huge and would be worth something as a sports station.  On the other side, with land and operation costs as they are, it could be a giant loss.  Even if the license was given away it would need to go to someone with a million dollars in the bank ready to cover the operational costs.”

Urick said that it’s becoming increasingly common for unprofitable stations to turn their licenses back to the FCC. He said, “If an AM station isn’t getting good ratings anymore, it is more profitable to sell the land the tower site is on, discarding the license, than continue to break even (if even) on operating the station.”

even if we did advertise the frequency for use within the U.K., either at a local or national level, there can be no guarantee that Radio Caroline would win the license.

I don’t know if there is a statute in the UK preventing former pirates from having station licenses. In the US former unlicensed broadcasters are prohibited from having LPFM licenses. However, they are not necessarily prevented from having full-power FM licenses. Ostensibly having been busted by the FCC for broadcasting without a license might make someone unfit for a licensed station under the so-called “character clause.” However there is precedent for former pirates later obtaining broadcast licenses.

Currently Radio Caroline is broadcasting online. As part of its anniversary celebration the station is advertising an on-air birthday bash broadcasting from the ship Ross Revenge April 22 through May 2. The broadcast apparently will be on 531 KHz AM in south Essex and north Kent, though it’s not clear if that is a licensed or unlicensed signal.

I sometimes think it’s ironic when US pirate stations try for licenses, but in Radio Caroline’s case I don’t think it’s ironic at all. UK pirates helped to break the BBC’s stranglehold on the airwaves, paving the way for non-government broadcasting. A private radio license wasn’t even available when Caroline was on the air. So, in a way it’s only fitting that Radio Caroline be able to eventually enjoy the result of it’s labor 47 years ago.

On the heels of my post about FCC enforcement of “legal” low-power AM broadcasting, I learn that Pacifica plans to jump into the LPAM arena. The plan is for Pacifica’s Los Angeles station KPFK to serve its Spanish-speaking audience with a network of Part 15 LPAM stations deployed strategically in Latino neighborhoods. According to a recent Radio World article, the LPAM plan is to compensate for the fact that KPFK only has 24 hours in a broadcast day, already split amongst many different types of programming, but with an apparently strong audience for its three hours of Spanish programming a night.

Networks of LPAM stations have been tried before. Perhaps the most prominent was Allston-Brighton Free Radio, a Massachusetts station that started out as a 20 watt unlicensed FM before going Part 15 LPAM. The station has been mostly defunct since 2003, but that doesn’t mean the idea isn’t a good one.

Rather, given the limited broadcast range of LPAM stations I think it shows that it’s difficult to keep a full schedule of volunteer DJs motivated and the station funded. Therefore KPFK’s idea of using LPAMs to rebroadcast a stream of already existing Spanish programming seems more sensible. According to RW the cost of a transmitter setup is just $850 — it likely will cost more to feed the station a good audio feed. KPFK program director Alan Minsky tells RW that the station won’t produce more Spanish programming. Instead it will rebroadcast its current Spanish block supplemented by programming from other sources.

However, I suspect that the FCC might pay a little more attention to a prominent licensed station messing around with unlicensed AM transmitters. Commission field agents will probably want to confirm that those transmitters are fully compliant with Part 15 regs.

This should be a very interested experiment to watch when it gets off the ground.

Last fall I wrote a post on unlicensed broadcasting on the AM band in the US. The impetus was reading an article on a rare FCC action against a station in Portland, Oregon, which caused me to track down the few other Commission actions against AM pirates in 2010.

The so-called Part 15 rules that govern permissible unlicensed broadcasting on the AM dial are somewhat more lax than the FM dial. This makes it a popular band for hobbyists and folks who want to serve small localized areas without breaking commission rules. However, it can also be easy to overstep these rules in the pursuit of gaining a bit more broadcast area.

As a service to would-be legal micropower broadcasters, the Low-Power Radio Blog recently compiled the technical reasons behind FCC actions against unlicensed AM stations going back to 2003.

One of the interesting elements of Part-15 rules for AM is that they specify the total amount of power a transmitter can use, along with the total length of the transmission cable to the antenna combined with the length of the antenna itself. Many clever amateur radio engineers have figured out ways to eek the most out of these constraints. And, from looking at this list of enforcement actions, it would appear that abiding these limits is well advised.

Six of the twenty-one cited actions were for stations that had transmission cables or antennas that were too long. The limit for both combined is three meters (9.8 feet), and in five cases the Commission notes the lengths they measured were anywhere from 5.4 to 28.2 meters too long.

For the other fifteen cases the FCC field agents reported a field strength–a measure of the power of the signal received at a particular distance from the transmitter. In these cases agents measured field strengths of anywhere from 43 to 9000 times the Part 15 limit. What this indicates to me is that these broadcasters were making no attempt to stay under that limit, and therefore making no obvious attempt to operate unlicensed stations in compliance with Part 15 rules.

This also indicates that there are few, if any, broadcasters who are trying to adhere to Part 15 rules but slightly overstepping the limit and getting a visit or nasty letter from the FCC. It all adds up to mean that if you want to dip your toes into the unlicensed broadcasting pool with low risk, going with Part 15 compliant low-power AM is probably the best way to go.

Radio World recently posted a brief item about three notices of unlicensed operation to three different persons that the FCC issued in Portland, OR to what is apparently the same station operating on the AM dial. There are a good dozen notices issued every month, and not every one gets reported on by RW. Apparently this one was notable because it was on the AM band and because the broadcasters allegedly were using 1710 khz, which is up in the so-called “expanded band.” Most unlicensed broadcasters use the FM band for which it’s easier to obtain transmitters and antennas.

However, pirates on the AM band are not that unusual, although the FCC sniffs out far fewer of them. In fact, the Commission’s Enforcement Bureau issued four additional notices to unlicensed AM broadcasters in Omaha, NE, Sublimity, OR, Brockton, MA and Malden, MA (though the FCC detected the Malden signal in November, 2009). Interestingly, the notice in Sublimity was actually issued to the City of Sublimity which the FCC says was operating from a water tower at comparatively high power.

What’s more interesting about this particular station is that the FCC claims the water tower functioned as part of the antenna system. According to the FCC’s Part 15 rules it’s permissible to have an unlicensed AM station that transmits with 100 milliwatts of power as long as “”the total length of the transmission line, antenna, and
ground lead (if used) shall not exceed approximately 3 meters.” However at the Sublimity station

the agent observed that the approximate length of the vertical whip antenna and the ground lead used by the station was 3 meters, however, the referenced antenna was attached to an unshielded radiating metal water reservoir tower and the height of the metal water reservoir tower measured approximately 100 feet (31.2 meters).

Due to AM’s long wavelengths, longer antennas increase your transmitting efficiency. Using a big metal water tower is clever, provided you don’t get caught.

Just for fun, here’s a short YouTube recording of a Grosse Point, MI AM pirate as received on an antique radio:

RCA Super Radio III

Having a nice radio with sensitive tuning and pleasing sound can really make the radio listening experience that much more enjoyable. Thanks to Herculodge I’ve learned that the classic RCA Super Radio III is available again at Amazon for a reasonable price of just under $50. This model is the last one in a line that goes back nearly 30 years. Originally branded GE, Super Radios are prized for their sensitive AM tuners that are bolstered by a larger-than-average ferrite core antenna inside. Super Radios also feature a large 6.5″ woofer and 2″ tweeter that put out very nice quality sound for a mono radio, particularly well tuned for listening to AM.

The Super Radio also has an “AM wide” switch which permits the radio to receive a slightly wider frequency range on stations that broadcast it. On AM frequency space is directly related to fidelity in terms of hearing more high-end. Unfortunately, with the AM band as crowded and full of interference as it is these days, it’s not as useful a feature as it was when the radio debuted in the mid-90s. Nevertheless, if you have a strong local AM station that you like to listen to, the “wide” setting may bring you clearer sound, especially during the day time.

I had a Super Radio III for a while in the late 90s and really enjoyed using it to tune in distant AM signals (known as DXing). The AM wide setting delivered very full sound on a local AM public radio station. Sadly, an untimely accidental blow to its volume knob made it difficult to repair, so I gave it to someone who was willing to give it a try.

Like most consumer electronics the Super Radio III is not perfect. Some radio enthusiasts note that its ability to pull in stations also means that it can pull in extra noise. Build quality has also been an issue at times, so it’s a good idea to buy it from a vendor with a good return policy.

My understanding is that the Super Radio III has been discontinued, so I figure that Amazon must have found a supply of them in a warehouse somewhere. If I hadn’t recently bought a few radios I would be seriously tempted to pick up a Super Radio III myself before they disappear entirely. When it looked like there was a limited supply of new ones left sellers were charging $100 and up. So who knows how long $50 ones will be available.

In terms of statistics, the article notes that there are fewer than a sixth (16%) as many digital AM stations than FM, totaling only about 6% of all AM stations in the US. Furthermore, even amongst the nation’s most powerful big market AM stations that are broadcasting in digital, “most of those transmit their digital signals only during the day.” Tellingly, RW also observes that, “[m]any of the stations on-air with AM HD are owned by members of the HD Digital Radio Alliance.”

The article points to several non-technical factors that might be influencing AM HD’s lack of success. One is the recent FCC decision permitting FM translator repeater stations to be used to rebroadcast AM signals. Another purported cause is the economy (which we can pretty much blame for nearly everything without further explanation). Finally, apparently station groups are waiting for their FM HD signals to start paying off before making further investments on the AM side.

Significantly, it appears that interference issues, including interference with a station’s own primary analog signal, are behind many stations turning off their digital signal. Furthermore, the issue of receivers switching between digital and analog signals when the radio can’t keep locked to the HD data stream is important. On FM the relatively similar fidelity of the analog and digital HD1 channels means that the “blending” between them isn’t particularly noticeable. But on AM the digital and analog programs sound very different, making the blending from one to the other very noticeable and often quite annoying.

Something I didn’t know before is that iBiquity, the owner of the IBOC HD technology, is offering a new “configuration” for AM stations that air mostly talk programming which reduces the digital signal bandwidth in order to reduce interference, heard most prominently on older high performance AM receivers. As a listener, however, I see the bandwidth reduction as a double-edged sword. While it may minimize interference, it also reduces fidelity, which can obviate some of the minimal gains associated with HD technology in the first place.

In a companion piece, Radio World also talked to a number of additional radio engineers not quoted in the first article. While a few, like Clear Channel’s Brett Gilber based in Tulsa, OK, consider the technology a success, others are less sanguine. Harold Beer, who engineers Michigan State University’s WKAR-AM said, “After years of encouraging listeners to get better quality wideband AM radios, we ended up degrading their listening experience with a 5 kHz bandwidth, –35 dB SNR analog signal once we turned on the IBOC digital.”

In the end, whether you read Radio World’s relatively balanced coverage or just listen to AM HD yourself, it’s hard to conclude that this digital medium is anything close to a success. The question is: will the radio industry see fit to throw more cash down the AM HD Radio money pit?

I’ve known about this station for well over a decade now. As a metalhead living in Central Illinois I’d occasionally travel north to the Chicago area or Milwaukee to see concerts and encounter banners and fliers for an all heavy metal station on the AM band called Rebel Radio. However, I can only recall hearing the station once when on the highway between Milwaukee and Chicago.

Music radio on the AM dial is nearly an anachronism now, and most of the practitioners now are either ethnic stations or easy listening. Nevertheless there are a few hold outs–mostly mom and pop operations or stations owned by relatively small groups–that program niche formats on AM stations. Being on the air for about sixteen years certainly qualifies WPJX 1500 AM in Zion, IL as a true AM music veteran.

Unfortunately, WPJZ isn’t exactly a powerhouse when it comes to transmission strength. In fact, the station broadcasts with just 250 watts from the far northeastern Illinois town of Zion, a good 38 miles from the Chicago city limits. What that means for a city dweller for me is that I simply cannot tune it in, no matter how hard I’ve tried. The stations serves southeast Wisconsin about as well as Illinois, still missing most of the major north suburbs of Chicago. Adding to the frustration is the fact that Rebel Radio does not yet have a web stream, although its website currently promises one soon.

Then, today while perusing their website again I noticed a note saying Rebel Radio is simulcast on a co-owned station, WKTA 1330 AM in Evanston, the first suburb north of Chicago, on Sundays from 4 to 8 PM. So this afternoon I tuned in Rebel Radio for the first time, thanks to WKTA.

First off, this is truly a heavy metal station, playing many examples of the genre from the more mainstream–like Metallica–to the lesser known–like Armored Saint. At least during this four-hour window there’s a live DJ spinning the tunes and talking quite knowledgeably about the bands and songs, pointing out local concert dates as appropriate. That element alone is quite refreshing and rarely heard on commercial radio, even if it also includes a too-long inane phone call from a friend of the DJ calling in from a Renaissance Fair.

In terms of fidelity, I’m not terrifically impressed. Contemporary heavy metal has a pretty broad frequency range and often is not mastered to be optimized for radio like a lot of pop and mainstream rock music. That means there’s a fair amount of sound in the high and low frequency extremes that AM radio doesn’t cover well. I think it takes some pretty good EQing and signal processing to make metal work well on AM. On the whole the station doesn’t sound bad, but the midrange and high end sounds pretty crowded and compressed. A little strategic equalization might let the high end come through a little better and make the station a little more listenable. I acknowledge that the main station WPJX might sound better than the simulcast that I can tune in. And, to be fair, on a portable radio or boombox the sonic compromises are far less perceptible.

Listening to Rebel Radio I was reminded of the Z-Rock syndicated heavy metal format. I first listened to it when I lived in New Jersey in the late 80s and early 90s when it was broadcast on an AM station out of New York on 1480. It didn’t always come in well in Passaic County where my parents lived, but I did tune in occasionally when looking for something different on the radio dial. Even at the time I didn’t think the sonic quality of metal on AM was that great.

Nonetheless, Rebel Radio proves that there must be a very loyal audience for heavy metal on the radio willing to deal with the compromises inherent in music on AM.

Where is the beef? Not on AM HD Radio.

One of the supposed advantages of HD Radio is improved fidelity over analog. As I observed in my listening test of HD on FM, there’s almost no real improvement for HD over the analog signal. The advantage for HD on FM, then, is the addition of one or two more channels of audio. However, due to the more limited sonics of analog AM radio, we are led to expect HD AM stations to offer significantly better fidelity; they don’t offer any additional channels.

But compared to FM, there are much fewer HD stations on AM. This is largely due to the fact that the AM band is seriously congested, with quite a bit of interference. Adding an HD Radio IBOC side-channel to a station greatly increases the potential for interference to adjoining analog stations. A secondary reason is that the AM band is dominated by talk radio formats where fidelity improvement is less important.

In Chicago iBiquity (owner of HD Radio technology) says there are seven HD stations on AM. Over the course of several days throughout the last few weeks I was only able to tune in the HD signal for three of these stations, WSCR, WBBM and WGRB. My Sony receiver detected an HD signal on two–WRDZ and WVON–but could not tune it in. The receiver detected no HD signal for two stations, WMVP and WRTO.

Two of the three stations with an HD signal I could receive are primarily talk stations, WSCR and WBBM. The HD signals of both had a modestly extended frequency range than the analog signal, but with clearly audible digital artifacting on the high end, similar to a medium bitrate MP3 (say about 96 kbps stereo or 48 kbps mono). However, wider frequency range is of negligible use for talk programming. For these stations the primary benefit of HD is the loss of background noise and interference, which can be distracting even on a strong AM signal.

One HD signal, WGRB, features both talk and gospel music programming. Depending on the source–some programs are recorded live in churches–there is a perceptible improvement in fidelity with music due to the extended frequency response. However, the high end artifacting and distortion due to the low bitrate is sometimes too distracting to my ear, leading me to prefer the analog signal, even if the compromise is less high end.

On the whole the only real benefit I can see for HD Radio on AM is the significant reduction in background noise. On FM this is a limited benefit, since background analog background noise is already very low by comparison. But on AM it’s quite noticeable and losing it is mostly welcome. At the same time, I can’t say it’s worth the trouble.

Of the three HD stations I could receive, the only one I’m likely to listen to regularly is news/talk WBBM, where I also heard the least sonic improvement. I chalk this up to the likelihood that the station’s airchain has been optimized for AM. Because the HD signal is broadcast as a lower power level than the analog, I have to work, moving the antenna around, to tune in the HD signal. When I’m not specifically trying to test HD reception, it’s unlikely I’d bother with the effort to get the HD signal.

Much more so than with FM, I consider HD Radio on AM to be mostly useless and not worth the effort. It’s especially not worth the loud digital hash noise I receive on my analog-only radios on the frequencies adjacent to the HD stations. It’s like a line of digital litter strewn across the AM radio highway.

After the jump are my technical details and listening notes for each station.

I did my AM listening test with a Sony XDRF1HD receiver connected to a Terk Advantage tunable AM loop antenna. For every station I attempted to optimize reception both by tuning the antenna for the corresponding frequency and rotating it. I placed the antenna in an open window and connected it to the receiver’s AM antenna terminals.

While I’m willing to work a little to optimize reception, I’m not really willing to go to great lengths for the purpose of the test. I’m looking at HD Radio not from the standpoint of an average radio listener, who I believe is generally not willing to work too hard to receive an HD signal.

These are the HD stations in Chicago according to iBiquity, and my listening notes:

670 WSCR – Sports/Talk – improved fidelity, with less compression than analog signal.

780 WBBM – News/Talk – modestly improved fidelity, still very compressed with strongly audible digital artifacting.

1000 WMVP – Sports/Talk – No HD signal detected.

1200 WRTO – Spanish Talk – No HD signal detected.

1300 WRDZ – Radio Disney – HD signal detected, but would not tune in.

1390 WGRB – Gospel – modestly improved fidelity, depending on source material.

1690 WVON – Talk – HD signal detected, but would not tune in.