All-digital AM HD: WWFD’s experiment is attracting attention

(Source: InsideRadio via Ulis K3LU)

All-Digital AM Grabs Automakers’ Interest.

The fate of AM radio in the car dashboard may pass through Frederick, MD. That’s where the latest experiment on an all-digital AM signal is taking place, on Hubbard Radio’s adult alternative “The Gamut” WWFD (820). The project, in conjunction with digital radio developer Xperi and the National Association of Broadcasters’ PILOT program, is already generating interest from carmakers in the U.S and around the world.

The Federal Communications Commission in July approved a proposal to allow WWFD to turn off its analog signal for the next year while remaining an all-digital operation. The aim is to use the real-world environment to conduct experiments designed to improve the all-digital AM service.

WWFD has 4,300-watts day (non-directional) and 430-watts night (directional) and the company proposes to operate with roughly the same output when it goes digital-only, 24-hours a day. Dave Kolesar, Hubbard’s senior engineer overseeing the project, said it’s an ideal station to use for a test case since it’s non-directional by day and directional at night.[…]

The switch has already been flipped and Xperi senior manager of broadcast technologies Mike Raide said preliminary results are encouraging. “We haven’t had any problems with OEM receivers,” he said, noting he drove 70 miles from the transmitter site and still picked up WWFD without any problem. In fact, one DX listener in the Pittsburgh area, roughly 300 miles away, said they were able to hear the station during the daytime. “That’s a testament to how robust all-digital is,” Raide said.[…]

“At a time when we’re all hearing rumors about car manufacturers cutting AM from their factory offerings, something like this could come along and show the auto manufacturers that AM still matters and AM has a digital solution as well,” Kolesar said.[…]

Click here to view the full article at InsideRadio.

In August, I received a strong lock on WWFD in neighboring West Virginia via my car’s built-in HD receiver. The next day, I made this short video of my reception on the Sangean HDR-14 (read review here) in neighboring Germantown, Maryland:

I found that WWFD covered the DC metro area quite well.

Post readers: Do you believe, as this article implies, that AM HD could revitalize the band?

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16 thoughts on “All-digital AM HD: WWFD’s experiment is attracting attention

  1. Terry Harvey

    I do not know why the US has to reinvent the wheel. Why not join the rest of the world with DRM (Digital Radio Mondiale).

    1. Tom Reitzel

      DRM would have been a smarter choice, but governments are largely controlled by lobbyists, i.e. corporations. iBiquity’s HD has problems with its analog fallback mode and secondary channels on FM. As it stands, HD works in practice, but not very well. If HD must exist, then MW stations with FM translators certainly should be required by the FCC to broadcast strictly digital (no fallback) on their MW station. This experiment with WWFD is WAY overdue and should be standard practice. I’ll leave you with a famous quotation;

      “Fascism should more appropriately be called corporatism because it is a merger of state and corporate power”. – B. Mussolini

    2. Jason

      DRM has been ruled out here in Australia, nonsensically I might add due to our vast distances and low population, in favour of DAB. DAB isn’t in use in rural/regional areas of Australia because nobody wants something that won’t work 10km out of town. Rural AM stations converting to FM is enough of a problem (and that’s all due to money as well, they want to restrict reception to only those in the local area to protect their antiquated revenue models, and there is one big owner of radio stations in Australia (Grant Broadcasters) who don’t broadcast online).
      As a consequence it’s going to be the case soon that fortuitous reception is more likely on your mobile phone when travelling Australia’s rural highways than your car radio (this is already the case through most of Western Australia)
      DAB is widely used across Europe.
      NZ don’t have a digital radio standard yet, they had some brief DAB trials but have since ruled out digital for now all together.
      Indonesia (population 270 million) hasn’t formalised a digital radio standard yet either but does have DAB trials in place.
      India is the main place I know of that has adopted DRM on medium wave.

      1. Mangosman

        I suggest you read, and the submissions. Note that the ACMA is yet to make its recommendations to the minister. DRM on the HF band has been received 20,000 km away (Radio New Zealand Pacific received in Spain)
        DAB+ range depends on the height of the transmitting antenna above the terrain and the effective radiating power. The high powered DAB+ transmitters mounted on capital city TV transmitter towers are covering 100 km radius depending on the terrain and the receiving antenna. A bigger problem is that there is only 8 transmission channels available and high powered transmitters have to be at least 336 km apart before the channel can be reused with different content.
        Only a few country stations have converted to FM because of a lack of available FM channels. shows huge areas of no coverage particularly in WA. It is mobile phone tower has a coverage radius of around 10 km. Go to the forest country in the South West and check out the mobile coverage! Drive off the main highways and see how you get on.
        NZ has been transmitting Digital Radio Mondiale for over 14 years, I agree there is no domestic digital radio of any type.
        India covers 600 million people with transmitters upto 300 kW power ABC maximum 50 kW.
        Indonesia has selected DRM for digital radio so they can cover the thousands of islands

  2. Jakob Speksnijder

    If this means that I get the same commercial nonsense that I hear on the FM now on the MW than leave it be. I can’t be listening to this nonsense while driving to work (the only time I listen to over the air radio for the news). In fact I would be looking forward to the car that eliminates the radio completely so that I have room for my HAM radio and listen only to emergency info if there is any.

  3. Tom Servo

    One of the benefits of this full digital operation is the elimination of the “saddle bags” on either side of the analog signal; they’re folded into the single 10 kHz channel where the analog audio used to be.

    The few clips I’ve heard of the audio are nothing to write home about, but the reception reports do seem to indicate that the digital-only HD on AM is a lot more reliable and robust than the hybrid version that makes such a mess of the dial for DXers.

    I would certainly not recommend a station go digital-only on AM or FM at this point if they’re a standalone operation, but an AM with a translator (or heard on a sister FM’s HD subchannel)? Why not? No one’s listening to the AM side anyway if they can help it.

  4. Robert Johansen

    There are serious flaws with HD digital AM radio, I have a Sony HD tuner and noticed digital drop outs when there was impulse noise, AM interference. I suggest leaving AM radio alone, allowing full 10 KHz bandwidth and discontinue HD AM

    1. Tom Reitzel


      Any standard can and will be improved, e.g. ATSC. iBiquity’s standard is no different and IS acceptable in its current form. Impulse noise is problematic with ANY digital standard and the revision of standards to minimize it will continue. Interference due to skywave conditions can also be minimized by shrinking contours and allowing selective stations to disappear when technically and financially prudent. Frankly, compared to ubiquitous buffering on the Spynet, a few occasional drop-outs don’t seem like much of problem while technical advances are incorporated in these digital standards, e.g ATSC, HD, DRM, DAB, etc…

      No more delays. Go strictly digital on the MW band today!

      1. Laurence N.

        Yes. Go strictly digital today. Break virtually every radio out there, as:
        a. Standalone FM radios in America rarely support HD, and those elsewhere definitely don’t.
        b. Plenty of autos in America are old or simply lack HD support.
        c. Countries have different standards meaning things stop being transportable between them.
        d. Most radios with HD only support it on FM.
        e. No successful standalone sets for receiving DRM exist.
        f. Every nondigital station would have to buy a new transmitter control system, paying a great deal in royalties to the authors of the digital system in use in the country.
        What would actually happen if you did that, as you propose? The result would be the death of most types of radio for the standard consumer, and soon the death of it for you. I would imagine that HD radio on FM bands would survive, but MW and SW would die fast. They would be replaced with satellite and internet systems for times when radio is needed by the standard consumer, such as in cars. Good one.

        1. Mangosman

          There is no importing of DRM radios into the USA because there is no transmissions of DRM there and international DRM broadcasts are not targeted at the USA.
          After 18 months there are now 1.5 million cars in India with factory installed DRM receivers.
 for receivers
          Xperi forces broadcasters and receiver manufacturers to pay royalties to use the HD radio technology, that is not the case for DRM or DAB+.
          The Europeans have done detailed analysis of the cost to the broadcaster comparing digital radio with the internet/mobile broadband. Digital radio is much cheaper.
          As for survival, the DRM in the medium and high frequency bands have the high frequency sound of FM along with stereo sound, without noise and interference.

      2. RonF

        > “Frankly, compared to ubiquitous buffering on the Spynet, a few occasional drop-outs don’t seem like much of problem while technical advances are incorporated in these digital standards, e.g ATSC, …”

        The funny thing about that particular example is that the most recent “improvement” of ATSC (3.0) is basically “European DVB-T2, with ideas from Japanese ISDB-T thrown in, and some untested and likely impractical US-only extensions. Oh, and some additional Digital Restrictions Management, viewer tracking, and targetted advertising extensions thrown in too”.

        “Spynet” indeed… 😉

  5. Rob

    A very good step and long overdue. MW (can’t really call it “AM” anymore) is great for regional coverage, and this is a huge step toward revitalizing the band. Let’s hope the FCC and commercial radio get this one right.

  6. Gary Donnelly

    I live in WV, about 60 air miles from Frederick, MD. I searched for and found this HD station when they were in testing. I got an email back from the station thanking me.

  7. Jake Brodsky

    I heard when 820 AM went digital and wondered about playing around with the AM HD. It would be a cool thing to try out except for two problems:

    1. How does it handle multipath, and other propagation issues, particularly when the skywave and groundwave interfere with each other? (Note that most AM receivers don’t handle it too well either)

    2. How well does it handle interference from adjacent channels?

    As much as I love the romance of AM, I would not mind seeing a digital modulation take hold on the MW AM broadcast band. Also note that it doesn’t have to be a voice broadcast. It can include bursts of information such as weather, traffic, web addresses for further information, schedules for concerts, phone numbers, etc.

    After all, when I’m driving, I don’t always have a pen and paper handy to write down a phone number…

  8. Tom Reitzel

    I have a problem with the FCC’s policy of using FM translators since it’s causing overcrowding of the FM band, but FM translators might be a blessing in disguise IF the FCC MANDATES (I hate that word… ;0) a strictly digital mode for AM stations with an FM translator.

    No analog fallback, just HD digital on the AM band… I hope this experiment succeeds wildly.


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