Time’s Almost Up For The FrankenFMs: The Impending Switchoff Of Analog TV

In a time when multi-channel digital TV is the norm it’s a surprise to find that a few low-power analog stations are still clinging on in some American cities. These are sometimes fill-in stations for weak signal areas, or more usually the so-called “FrankenFM” stations who transmit static images or digital patterns and derive income from their sound channel lying at the bottom end of the FM band to form unintended radio stations. Their days are numbered though, because the FCC is requiring that they be turned off by July 13th. There’s a way forward for the broadcasters to upgrade to low-power digital, but as you might expect they’re more interested in retaining the FrankenFM frequency from which they derive income.

The industry is represented by the LPTV coalition, who have requested permission to retain their FM frequency alongside their digital service. This has faced stiff opposition from other broadcasters, who see the very existence of the FrankenFM stations as a flagrant flouting of the rules that shouldn’t be rewarded. The FCC have yet to make a ruling, so there remains a slim chance that they may win a reprieve.

The sad tale of the few lingering analog TV stations in the USA is a last flickering ember of a once-huge industry that has been eclipsed without anyone but a few vintage technology geeks noticing, such has been the success of digital broadcasting. But analog TV is a fascinating and surprisingly intricate system whose passing however faint is worth marking.

Header: Tiia Monto, CC BY-SA 3.0.

30 thoughts on “Time’s Almost Up For The FrankenFMs: The Impending Switchoff Of Analog TV

  1. I, for one, welcome my digital overlords. As a video producer and sometime engineer who had to deal with NTSC waveforms, color bars and calibration, I don’t miss it at all. Color television was always a kludge tacked on to the well-designed B&W standard.

    Time to end its misery.

    1. its still NTSC (well here in the states) its just now carried on a extremely weak digital signal born in the early 2000’s. DTV is the suck if you live more than 15 min out of town and basically pissed a bunch of money away to tell everyone “go get cable cause your local stations wont work 20 miles away enjoy your free converter”

        1. It would be easier for the laymen if there wasn’t a bunch of scamtennas on the market that are no better than rabbit ears for $5 to $100. If you can’t see what it’s meant to be doing, i.e. yagi-ing, quad bowtie array-ing etc, then it’s just expensive junk. Also every 10ft higher you can get it, is probably worth the same as spending additional $20 chunks on progressively fancier antennas. … well, until you’re 150 miles out and actually need a 40dB yagi on a 60ft mast.

    2. It’s weird, I always felt exactly the opposite way about NTSC vs RS170.

      True, NTSC was a pain to work with, and I will not miss dealing with the mysteries of how everything in the signal affected everything else all the time, but I really have to hand it to the engineers who figured out a way to shoehorn an entire second signal in there on top of the first while keeping the same broadcast bandwidth and backwards compatibility.

      Though, admittedly, my life would have been made *much* easier at times if they could have kept 30.00 fps instead of slipping it down to 29.97 (to prevent harmonics of the color carrier from falling in the wrong place in the spectrum)

  2. So they are broadcasting static images on “channel 6” which has a lower edge of 82 MHz with the audio FM carrier for the analog TV channel is at 87.75 MHz which is compatible with most FM receivers. That is an awful waste of RF spectrum, for greed.

    1. I imagine that there will eventually be a change over to digital radio eventually as well. Most people are already doing digital audio, through their phones anyway. Analog takes up more space, and there are a limited number of possible channels, making owning the rights for that frequency valuable and profitable.

      1. Be careful what you wish for. You might get it. There are three big problems with digital radio.

        One is that the existing systems just don’t sound all that good. They promise “CD quality” audio or better but they don’t deliver it in the real world. The most basic problem is that they’re not using enough bits; station owners try to squeeze in too many channels rather than making sound quality a priority. Ask anybody in the UK about the mess that DAB is there. Or give a listen to SiriusXM here in the US; there is something subtly “off” about its sound that makes long listening sessions, at least to music, unpleasant. (SiriusXM is satellite rather than broadcast. But it’s the only example of pure digital available here, and if we ever do authorize purely digital broadcasting rather than hybrid digital/analog broadcasts the station owners will surely succumb to the same pressures.)

        Second is that they don’t behave well in challenging reception areas. Unlike television, the most important use case for radio is on the go, especially listening in cars. A single broadcast tower simply can’t provide enough signal coverage; people lose reception as they go behind buildings or hills, into tunnels, and so on. On analog radio the signal gets noisier but mostly doesn’t disappear, and people live with that. But digital radio drops out completely, leaving gaps in reception; listeners don’t like that at all. And listeners in weak signal areas at a distance from the transmitters lose the ability to listen at all.

        Finally, there is a huge installed base of radios. Those car radios, in particular, are not easy to replace. Their form factor is not standardized (there were attempts to do that but the car makers keep refusing to cooperate), so it may not be possible to find a replacement radio for any given car. In some recent cars, notably Teslas, the radio is completely integrated with the rest of the car’s electronics and is impossible to replace. Eliminating analog radio broadcasts would leave a lot of people with the unpalatable choices of spending a lot of money on a new receiver (if they can even get one) or not listening at all.

        1. “HD Radio” in the states is digital radio, shoehorned into the side bands of the analog channel. Depending on how many subchannels they try and cram into it, it can sound good, at least better than the analog counterpart. The good thing about it when the digital signal becomes too weak the HD radios will gracefully fall back to the analog broadcast. If you have ever looked at FM broadcast on an SDR, the digital signal is what looks like tire ruts on each side of the analog waveform https://fmradiodx.files.wordpress.com/2014/02/hdsdr3.jpg

          HD radio also works on AM, and can make AM channels sound as good as FM channels.

          There is really absolutely no reason for analog AM/FM broadcasting to go away in the states because they have managed to cram the digital counterpart into the unused parts of the analog channels. Unlike other countries who have switched to something that DAB which is entirely digital and requires either using a whole new band, or shutting off the analog so the digital broadcasts can use the same band that was analog.

          1. HD Radio is not without its problems.

            In hybrid mode (combined digital + analog, which is what nearly all stations using it in the US are using), the signal is wider than a standard analog AM or FM signal. That can cause interference to stations on adjacent channels.

            Usually that’s not a problem on FM, since channels on that band are supposed to be allocated such that stations on adjacent channels are never available from any given location, but that isn’t quite true; there are some places where, due to anomalies of geography or propagation, it IS an issue. I once lived in one of those places, an area of Long Island where WNEW-FM (New York City) and WDRC-FM (Hartford CT) both came in at about the same strength; fortunately, the directions to the two were about 90 degrees apart so clean reception of both was possible with a directional antenna. (Hartford was much more distant, but propagation was enhanced by the fact that a significant part of the path went over Long Island Sound.) Tropospheric ducting can result in adjacent channel interference happening in locations where the distant signal could not normally be heard, but that will usually be an issue only a few days or nights a year.

            The adjacent channel problem is much more severe on AM because signals carry for hundreds of miles at night. Most stations that use HD Radio on that band are only authorized to use it during the day because the digital sidebands were causing too much interference to other stations.

            HD Radio in hybrid mode also has serious range limitations. The digital signal is not receivable from nearly far away as the station’s analog signal. In part that’s because the digital sidebands are required to operate at much lower power than the analog signal to mitigate the adjacent channel interference problem. HD Radio receivers automatically switch back to the analog signal if the digital one drops out, but that causes a noticeable shift in audio when it happens and only works for the primary signal; if you’re listening to an HD subchannel it cuts out completely.

            HD Radio in pure digital mode has only been used in the US for a few experimental operations. More power can be used for the digital signal so range isn’t as much of an issue, and the signal is comparable in width to a standard analog AM of FM broadcast. But, of course the broadcast can’t be received by a standard radio at all, so it’s not feasible for stations to switch over.

            HD Radio, at least on FM, does sound pretty good in most deployments. (I have never heard HD Radio on AM because there are currently no AM stations here in Boston that are broadcasting it; all of them that had tried it have discontinued its use as it did not have enough advantages to justify the additional costs.) The codec is a slightly modified version of AAC, changed just enough to be incompatible with the standard one to make the system more proprietary. (There is a modification available for FAAD, a free software AAC decoder, that can play it.) The presence of analog fallback means that stations have to allocate enough bits to the primary signal to achieve good sound. (Having the station sound BETTER if you turned off the HD capability would be a non-starter.) But a pure HD Radio signal would no longer have that constraint, so it’s likely that most broadcasters would succumb to the temptations of quantity over quality just as they have in other digital broadcast systems.

      2. Digital Radio, I hope not! One can do one million samples of the analog music and you still end up with pieces of music instead of actual music as creator intended. How do you explain $1500 to $2500 for quality turntable?

    2. Maybe FCC could transform ther TV license in a radio license, and the problem is solved. Before switch of the actual TV station here was interesting even only on audio. When the FM frequencies got freed the frequency passed on a really boring stations….

      1. The problem is that most cities don’t have anywhere to put that radio license. All the available FM channels are full. The FM band could accommodate more stations if we reduced the required spacing between channels, but that would cause unacceptable interference in some older receivers. The FCC is not going to grant radio-only licenses for 87.75 because it would make it impossible to put a channel 6 station on the air.

        That’s akin to how we were able to pack a lot more stations into the UHF TV band after the digital transition. The new receivers are much more selective so they don’t need multiple channels on either side to be vacant, and the transition made all the old bad receivers obsolete.

  3. Dumb question, BUT will they finally get rid of non-HD channels, and stop offering HD as some sort of “upgrade”?

    Not that I want TV at all, it’s just that concept that grinds my gears..

    1. Are you kidding me? In Canada (Ontario) there is still a charge on a landline bill for “Touch Tone” service, and you can’t cancel it because you can only use touch tone so even if they get rid of non-HD channels HD will still be an “Upgrade” and charged as such.

      1. Pretty sure pulse still works on the copper. Should get everyone with a copper line to have a touch tone strike for a week (A lot of phones still have a switch) because I think it takes more energy now than modern tone equipment. Everybody pulse dial, cost them money. I don’t have a Bell line any more though. We had an ancient plan, paying two or three times what anyone else was, had to use a 3rd party long distance service so as not to give them another $40 a month they didn’t deserve. Tried to change the plan multiple times, nothing happened, gave it a concerted effort, calling them twice a week for a month, nothing, cancelled service altogether… all seemed well…. then two months after that they apparently silently billed me for something… then sent it to collections… and 6 months later I have to yell at them again when I start getting collection calls over this $10 out of nowhere. So Bell is on the “never again do I do business with them” list.

        1. That’s the weird part. In the early days, TouchTone was a premium, so an extra fee made sense. But Bell Canada never dropped that fee. As I recall, pulse dialing takes more time, so the decoder can’t be used for as many calls. So it was in Bell’s interest to get people to switch over. Twenty or maybe thirty years ago they went to the CRTC about dropoing the fee, but they wanted to increase the monthly fee by the same amount. The CRTC denied it.

          We never bothered, so definitely pulse phones still work. I never regularly tried Touch-Tone on the modem to see if ever was a change, I did try it early on with no success.

          I guess we have Touch-Tone now, , a switch when Bell Fibe was installed. I’m not certain, we dumped the Bell phones to at that point (except for the wall mount dial phone in the kitchen) so the phones are cordless.

    1. It’s about over the air analog TV, which has already been switched off almost everywhere in the world. You can still use your own TVs and hook up a little modulator to an antenna and receive it around your living room or something like it.

  4. Can’t believe this is even under consideration. Contrast an unprofitable pirate or charity radio station operating without an FM license. With no advertisers paying for a captive audience to rain propaganda upon, this wouldn’t even be on the table.

  5. Although we listened to CH6 from near 60 Mi away (a major network) it was their local news that made this worthwhile. I understand at one time that channel could be used for FM if there was no CH6 at some distance, but in the summer when skip happens TV’s would get slammed with 3 times louder distant radio stations. Now they’re gone.

    When radios got digital tuning this ability should have been left out. Then they made audio only pocket radios for TV and AM/FM but only VHF TV. There was one table model that got both TV bands, a product for the blind. The way it stands now they should be allowed a FM license along with the higher deviation, not TV-NTSC.

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