Radio Waves Podcast #240

Radio is responding to the novel Coronavirus pandemic, though unlike, say, toilet paper, radio stations are on the hunt for in-demand items like microphone windscreens and remote codecs.

They need windscreens so that each personality can have their own to prevent the spread of viruses, and codecs so that stations can have personalities broadcast from remote locations — including their own homes — via computers.

Like other businesses, many station owners are having as many employees telework, including people in sales, programming, and engineering. Personalities are next, as home and remote studios are connected. It may make for an odd sound for a while, but it is one way stations are coping.

On the Air

I was talking to my wife about how cool it would be to program an AM music station — you may have heard me say that before — when I realized, there actually are a small handful in our area already.

Not what I would do exactly, but it at least gives a fighting chance for those who own a fully stock classic car from the 1960s or prior to listen to the radio without adding an FM converter. In case you missed it we have:

KSUR (1260 AM), playing oldies from the 1950s through the ‘80s. The signal is limited, unfortunately, as the transmitter was originally designed to serve the San Fernando Valley area, but it does reach most of the metro LA area and parts of surrounding cities.

KRDC (1110 AM) playing country via a Disney — yes Disney — programming service. The signal is still a bit weak — the original KRLA used the same frequency and broadcast site, and it was never stellar in the fringe areas. But it does hit metro LA strongly.

XEPRS (1090 AM) plays a version of top-40 from studios and a transmitter based in Rosarita, Mexico. Interestingly, the format is a simulcast of KJAV/Brownsville Texas, which is an FM station at 104.9. It is primarily an English-language station but some cool Spanish-language songs are in the mix as well.

More AM

Over the years there have been a few attempts to “revive” AM radio, as FM stations grabbed the available audience away from the once-dominant band. The most known is AM stereo, which was approved for use in the 1980s even though it dates back to the 1950s (stereo was developed for AM at roughly the same time as FM but the FCC refused to allow its use on-air in order to help give struggling FM stations an audio boost). While the various systems worked well, it was a bust for a variety of reasons.

Other initiatives included a system in which the audio was actually harmed in an attempt to boost perceived audio quality on bad AM radios. It worked by boosting the highs on the station’s end, so that cheap/bad radios would pass through more treble and help the sound. Good radios ended up sounding distorted and harsh unless they had the appropriate circuit to counteract … that system is still in place. FM actually uses something similar.

To cut interference between stations, stations were eventually ordered to limit fidelity. The idea being that humans (especially older humans) don’t hear much above 10 KHz, so just roll them off. So while it worked to reduce interference, temporarily as it turns out, stations sounded worse once again.

The latest improvement is digital in nature, called HD radio (AM and FM) in the US and a competing system DRM (AM only) in most of the rest of the world. Currently, the systems operate in hybrid mode, in which a digital stream “sandwiches” the analog signal, to be decoded by special radios. The system works reasonably well, especially on FM.

But while the AM is almost eerie when the digital signal kicks in, there is a problem when it comes to HD AM in that the analog signal is compromised. Analog audio is cut even more — to 5 KHz, the same as an old telephone, to allow the digital signal to “fit” within a station’s frequency space — and the digital signal actually causes more interference to adjacent stations than the old high fidelity version of AM before all of this started.

It’s basically a hot mess, though when received well, AM HD sounds great.

But now there’s a fix: all-digital AM. The idea is that if you turn off the analog signal, you can fit the digital signal well within a station’s assigned frequency, increasing fidelity even more and reducing/eliminating interference. Basically, the idea is to do to AM shat was done to television. The big downside? Most current radius won’t pick up the station, obviously limiting the size of the audience.

The FCC has been allowing some stations to try it out experimentally; now it proposes to allow all-digital AM for any station that wants to try it. On a volunteer basis. The commission was taking comments in response to the proposal through March 9; our own local Mount Wilson Broadcasters owner Saul Levine sent me his comments in support of allowing AM stations to broadcast in 100% AM digital mode, which I’ll quote in part below:

“AM in the 100% digital mode would provide better performance and be competitive with existing FM facilities. Operating in the 100% digital mode, however, will take many years to become profitable until a majority of radios are compatible with the technology,” wrote Levine.

“Mount Wilson took a gamble in 1959 placing an FM station on the air when AM was dominant and FM receivers were not prevalent, but the investment paid off. AM operators need to approach this new technology and its challenges the same way. One hundred percent digital AM has the potential to revive the AM Band. We urge the Commission to adopt a policy of allowing AM stations to operate full time with digital technology.”

The FCC is expected to rule on the issue in the coming months.