(Source: Radio World)
All-Digital on the AM Band? The FCC Might Allow It Soon
AM radio station operators in the United States may soon have the option of switching their transmissions to all-digital.
It’s not a done deal; but the concept is about to take a step closer to reality, because the Federal Communications Commission will consider a proposal at its next meeting that would start a process. It will take comments on whether to allow AM band licensees to make the switch if they want.
Ben Downs, VP/GM of Bryan Broadcasting in Texas, petitioned the FCC in March to initiate a proceeding to authorize the all-digital mode of HD Radio.
Allowing stations to use all-digital transmission is an idea that some broadcasters feel could give business-challenged AM stations in the United States new life or at least another option. Turning off their analog signals would mean that most existing receivers could no longer pick up that signal; but many AM broadcasters are currently heard on FM translator simulcasts now. And adding the all-digital AM option could open up new possibilities for them as the number of digital receivers in the marketplace continues to grow.
[…]Chairman Ajit Pai described the proposal in a blog post Monday: “Just as the FCC is trying to keep pace with changes in the market, so are AM radio operators, and the commission wants to give them as much flexibility as possible to compete in the digital age,” Pai wrote.[…]
Read the full article at Radio World.
Click here to read the proposal (PDF) that will be discussed at the November FCC meeting.
The Radio World article mentions WWFD in Frederick, MD–a station that has been broadcasting AM digital for over a year. We posted a note about this last year and I even included a short recording/video with reception when traveling through the area.
Today the FCC has just approved the option for MA3 mode.
Interesting commentary on this from the WWFD transmitter engineer:
I can hear WWFD at my home QTH, about 70 miles away. I use a tuned loop and it comes in pretty well. BUT…just a bit of noise and it goes into “HD blinking mode” quite fast.
A static crash from a lightning strike will not be kind to an all-digital MW band in my opinion.
All of you hearing this signal might consider giving feedback https://hdradio.com/stations/feedback/
I would assume that this problem will not exist in all digital transmissions “There’s an echo or the sound seems out of sync or there’s a time delay”
The last bastion of free and simple communication … A cheap AM transistor radio about to go the way of subscriptions and exclusivity and upgrades …
Oh goody , mind-numbing talk radio via the magic of digital.
Xperi charge licencing fees to the receiver manufacturers as well as broadcasters for the use of the HD radio standard. So an and on decoder is unlikely. These days the whole RF and decoding of signals is done in a single chip.
Jake, a better option would be to use the virtually deserted TV channels 2 – 6 for Digital Radio Mondiale. Their channels are half as wide as an FM channel and a quarter of the width of a hybrid FM channel. With a lower frequency than FM the signals travel further. This system will easily carry 3 programs per transmitter.
If you want to stay in the medium frequency band (530 – 1710 kHz) DRM will work there as well. You use a 20 kHz wide channel just like WWFD. The advantage is that there is no carrier in DRM thus saving at least 67 % of the electricity consumed. If you want to simulcast AM and DRM as an example you might have AM on 1000 kHz and DRM on 1010 kHz, but like HD radio the power of the digital signal has to be reduced but at least only one adjacent channel is used.
Note: DRM in a 20 kHz wide signal is noise free, has all the high frequency sound missing in AM, it contains stereo sound, has emergency warning system which will wake the radio tune the audio warning, show multipage detailed instructions on what to do including coloured maps.
Currently India has 37 DRM transmitters on air some of which are 300 kW (max in the USA for AM is 50 kW) which is covering double the USA population. In the first 18 months they have sold 1.5 million cars which have DRM receiver installed on the production line.
DRM is also broadcast in high frequency (short wave). For more information http://www.drm.org
Is there a digital demodulator that i can install on my SP 600 to avoid obsolescence?
I live about 20 miles from WWFD. I’d like to point out that on channel digital as a replacement for AM may not be such a bad idea. It’s not as bad as the digital sideband silliness that got perpetrated by fools who thought it couldn’t possibly interfere with other radio stations (wrong).
I’m going to miss the sound of AM radio on the band when things go digital, but I have to confess that we’re overdue for that change. Frankly, with all the noise sources on the MW band, it’s time. Even the former “clear channel” stations such as WLS, WSM, CFZM, and others have difficulty getting a clean signal above the noise.
I’m also going to miss the fun of tuning around with a crystal radio.
Ideally, I’d like to see these digital broadcasters pushed on to a new band, perhaps one of the tropical bands such as 90 meters. It would be a good test and the newcomers could potentially do very well with extended coverage at night.
I think it would be rather interesting to start using digital modulation with the AM radio “graveyard” frequencies of 1230, 1240, 1340, 1400, 1450 and 1490 kHz. If the modulation can survive that, maybe there is merit to migrating everything else over to it too.
About 6 months ago, I revisited a facet of my radio interest in the form of DX’ing the AM radio band, and I have found it fascinating all over again. It has become a great evening past time and I have been astounded how may stations are still out there waiting to be discovered. At the same time, there is evidence that the AM band is well on its way toward the conversion to internet broadcasting. So many stations already offer internet alternatives that I often wonder if I am listening to my last “over the air” broadcast from some of them. While I see that practical considerations will eventually remove the romantic hiss, crackle & QRM from distant radio signals and replaced them with canned offerings of far more sterile pre-recorded podcasts received via wi-fi in crystal clear clarity, I cannot help feel some sadness for an era that, in its hay day, was a great and golden time. I will remember it fondly and take great pleasure in being fortunate enough to have experienced and enjoyed it.
I live about 30 miles away from WWFD. It comes through as a steady hiss about 10 kHz wide at 820 kHz on an analog radio. You can see and hear it on NA5B’s SDR site, http://na5b.com:8901/. At night the power is reduced, you can null it and hear Texas or Cuba.
I can’t imagine what the all-digital physical plant at WWFD cost; nor can I guess at how many digital radios are regularly tuned to it during the broadcast day. Digital radio has a way to go. Then again, never say never.