• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

What’s Going To Happen To Legacy Broadcast Bands When The Lights Go Out?

And for a glimpse of what an abandoned band might sound like, find a shortwave radio and tune what used to be the marine band (roughly 2000 to 2800 kHz. You might hear time stations WWV and WWVH on 2500, but the ship-to-shore and ship-to-ship traffic that used to keep this band busy and interesting for SWLs has all moved on.
Or look at the Tropical Bands that used to have hundreds and hundreds of regional short wave stations, whether in Africa, SE Asia or Latin America. All but a handful are gone now.
 
Countries that have sunset AM generally have had migration plans in place for existing AM stations.

Canada had fewer AM's per market, and less populated FM bands when they started moving CBC stations and allowing private ones to migrate.

Mexico reduced second adjacent FM protections and moved 80% of existing AMs to FM. Throughout Latin America, attrition or planned moves to FM allowed the AM band to depopulate.

The US has no plan, other than the patchwork translator program for AMs.
Could the AM band be saved if there were fewer stations and more power given to the remaining ones.
 
A megawatt transmitter won't help with audio quality, and even if it did, AM has gotten short shrift audio-wise from automakers for years. Nothing, repeat NOTHING, is bringing young listeners back to AM. Sorry, DXers, the band is doomed.
I don’t care about AM. However is there a way to make the audio quality better with the current system.
 
I don’t care about AM. However is there a way to make the audio quality better with the current system.
Yes. You could bring back the 20kHz bandwidth channels, like WQXR 1560 was at one time (1940s?). That wouldn't prevent the pops and interference from power lines or other infrastructure, but it would make the audio sound a lot better if you have a sufficiently strong signal.

The problem with this, and essentially any other "fix" for AM transmission: it requires all new receivers.
 
Throughout Latin America, attrition or planned moves to FM allowed the AM band to depopulate.
Looks like Brazil is getting some action on its expanded “eFM” band 76-88 MHz. A Sao Paolo station on 77.9 MHz was received via E-skip in Portugal, and apparently a few other stations are now on the air in that extended band.

This list includes the new eFM stations in Brazil, but it’s not clear how many are actually on the air…Sao Paolo has a bunch of them: tudoradio.com - O Rádio: Migração das AMs - Levantamento no FM

Also a brief overview of the expanded FM band in Brazil: Wikiwand - FM extended band in Brazil
 
Last edited:
Or look at the Tropical Bands that used to have hundreds and hundreds of regional short wave stations, whether in Africa, SE Asia or Latin America. All but a handful are gone now.
Absolutely. I remember winter days where a bunch of African stations came in around 4:30pm, until the Latin American broadcasters took over later in the evening. Around 11pm, the Africans started signing on again. I was taking Spanish class, but I learned Spanish listening to stations like Ecos del Torbes (who at the time had a fairly slow speaker hosting "Lo Que Esta Noche Recuerda", Shortwave, at the time, was my only real chance to hear spoken Spanish. Now there are Spanish language movies, Spanish tracks on current movies, all sorts of things.
 
Won’t raising the power help with the quality issue?
Quality issues involve inherent frequency response (or lack thereof), distortion, inconsistent reception ability, and lack of programming that would interest an audience who already uses their smartphones as a primary device for entertainment, news, and just about everything else.
 
Yes. You could bring back the 20kHz bandwidth channels, like WQXR 1560 was at one time (1940s?). That wouldn't prevent the pops and interference from power lines or other infrastructure, but it would make the audio sound a lot better if you have a sufficiently strong signal.
Additional audio bandwidth won't eliminate terrestrial noise.
The problem with this, and essentially any other "fix" for AM transmission: it requires all new receivers.
And, in most instances, new transmission-related equipment.
 
A megawatt transmitter won't help with audio quality, and even if it did, AM has gotten short shrift audio-wise from automakers for years. Nothing, repeat NOTHING, is bringing young listeners back to AM. Sorry, DXers, the band is doomed.
Digital transmission would mitigate a number of reception and audio issues, but it is doubtful anyone outside of hard-core radio geeks would buy the receivers.

To use a housing analogy: With AM, you are not just looking at major repairs, or even a gut job renovation. It needs a complete "scrape and replace" teardown. But would anyone want whatever you replace it with?
 
Or look at the Tropical Bands that used to have hundreds and hundreds of regional short wave stations, whether in Africa, SE Asia or Latin America. All but a handful are gone now.
There has been chatter out of Brazil the past few years about reviving the tropical bands using DRM, but outside of some tests conducted by public broadcaster EBC, nothing has happened yet. I have a feeling this will go nowhere, especially if the "eFM" band catches on in that country.

There is one Brazilian transmitter manufacturer that used to include DRM SW transmitters in their product lineup, but the website link to those no longer works...wonder if they dropped those products in order to concentrate elsewhere?

 
I don't see the legacy broadcast radio bands (either AM or FM) going away for the simple reason that there is nothing else that they could be better used for. Neither the domestic AM or FM bands have any value whatsoever for data transmission or any sort of cell service, so there is nothing to repurpose them to. What will likely happen is that the AM band will get less cluttered as more stations shut down and perhaps the stations that stay on the air will get sold to whoever can find something to do with them. As for FM -- I think it will maintain a solid listener based for at least a few more decades, enough to keep the legacy radio companies interested in continuing to milk their stations. When they're no longer interested in doing so, stations will get sold to smaller, niche companies with an interest in broadcasting and most will go on. Alternatively, some licenses might get turned back to the FCC and auctioned off to new owners (at much, much lower prices than we've seen in previous auctions). So my suspicion is that even in thirty years the FM band will be pretty full in major and medium markets.
 
Either the FCC will continue to enforce use of the AM band or hobbyists and preachers or even private two way communications will take it over. Even today (2023) there are a variety of pirates using the broadcast bands and the FCC is not very successful at silencing them all. The number of working AM radios would have to become much smaller (due to wearing out or being thrown away) before broadcasting on that band will cease.
 
Neither the domestic AM or FM bands have any value whatsoever for data transmission or any sort of cell service, so there is nothing to repurpose them to.
I have this memory of some kind of phone service being on 1700 AM, which had to be discontinued when the AM band was extended.
 
I have this memory of some kind of phone service being on 1700 AM, which had to be discontinued when the AM band was extended.
1970s era cordless phones for landline connections used frequencies between ~1690 and ~1770 kHz for the base stations, while the handsets used frequencies around 49 MHz. Used to be quite a lot of activity for these. They were replaced by 46/49 MHz units in the 1980s, later by 900 MHz, 2.4 and 5.8 GHz sets, then the current DECT 6.0 standard which operates 1.92 to 1.93 GHz.

Check the “Expanded AM Band” thread under the Specialty>DX and Reception forum, where there was an extensive discussion about this very topic.
 
Noise, particularly from ever-more-present electronics, is what's killing AM radio.
One reason people originally gravitated to FM - and its entire raison d'être - was freedom from noise. For the longest time, though, that meant specialty formats, such as classical programming, were what drove adoption. After the dark days of the 1950s, FM started growing again, thanks to the adoption of stereo programming (not a part of FM originally) and the adaptation of more popular formats more attuned to shifts in taste. In more concrete terms, people started getting tired of screaming Top-40 jocks and constant patter and commercials and gradually shifted to FM.
Honestly, high-power operation isn't going to save AM - it certainly hasn't in Europe - and low-power operation isn't going to either - the experience with it in the Netherlands is very mixed and many of the LPAM stations there are having a rough go of it.
Nor should FM stations be complacent - HD isn't going to save FM, even though it does a decent job of solving problems with multipath - and the programming on many stations doesn't provide the kind of experience that many listeners are now looking for.
 
Noise, particularly from ever-more-present electronics, is what's killing AM radio.
One reason people originally gravitated to FM - and its entire raison d'être - was freedom from noise.
And superior frequency response, proper stereo, lower distortion, lack of night heterodyne, minimal loss of signal going under overpasses,.....
Honestly, high-power operation isn't going to save AM - it certainly hasn't in Europe - and low-power operation isn't going to either - the experience with it in the Netherlands is very mixed and many of the LPAM stations there are having a rough go of it.
Nor should FM stations be complacent - HD isn't going to save FM, even though it does a decent job of solving problems with multipath - and the programming on many stations doesn't provide the kind of experience that many listeners are now looking for.
The only way of improving AM quality, is if stations went full MA3 (digital mode). Current HD-capable tuners already can receive it. The audio quality and noise floor equals if not exceeds FM quality. But with only 20% vehicle-only penetration, a station going full MA3 mode would be on it's own for quite a while.
 
And for a glimpse of what an abandoned band might sound like, find a shortwave radio and tune what used to be the marine band (roughly 2000 to 2800 kHz. You might hear time stations WWV and WWVH on 2500, but the ship-to-shore and ship-to-ship traffic that used to keep this band busy and interesting for SWLs has all moved on.
A better SW analogy would be the 31 Meter Band, which used to be wall to wall with signals. Not so much today. I think the AM band in 20 years (or even less) will be the same way.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom