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Can "processing" bring AM radio back from the dead?

stewie

stewie

Star Participant
stewie said:
Saw this blog post.

Given the source, it's probably good marketing but I was curious if anyone has heard one of these and if it lives up to the hype. With only 5Khz available on most AM radios these days, I don't see how this makes a difference.

Thoughts?

https://blogs.telosalliance.com/when-am-audio-can-run-the-gamut-omnia.7am-is-the-answer
Click to expand...

Any modern audio processor can build density which is important for AM. This is purely marketing and little science.
The most important affects on AM audio are transmitter capability and antenna matching.
 
How would this help erase all the snap, crackle and pop interference that bothers AM today? Seems the only way to eliminate that is to bump up the pow-pow-power but then you run into problems with other AM's. The only way to resolve that is allow a dozen or so national AM's blasting 100KW signals across the USA separated enough that they don't step on each other. Don't see any of that being feasible.
 
wavo said:
Any modern audio processor can build density which is important for AM. This is purely marketing and little science.
The most important affects on AM audio are transmitter capability and antenna matching.
Click to expand...

Not to mention the quality of the receiver, which hasn't improved in a very long time.
 
TheBigA said:
Not to mention the quality of the receiver, which hasn't improved in a very long time.
Click to expand...

That, and physics.

Digital modulation improves frequency response and noise, but depending on the environment, the audio can suddenly drop and return. Which is worse, loud buzzing when going under a freeway overpass or having the audio drop out completely? Neither are good.

Aggressive audio processing to the point of loss of any dynamic range will sometimes cover noise floor inherent with Medium Wave, but it causes listener fatigue and is useless for music.

This is a similar claim made by a certain audio processor manufacturer back in the 80's. The claim was by using their FM audio processor, you can reduce multipath interference. Problem is, multipath is caused by reflections off of natural and man-made physical things. Altering how the audio is processed has no control over environmental conditions between the transmission and receiver antenna.
 
Everyone knew there were limitations to AM in the 1930s. That's why Edwin Armstrong invented FM.
 
landtuna said:
How would this help erase all the snap, crackle and pop interference that bothers AM today? Seems the only way to eliminate that is to bump up the pow-pow-power but then you run into problems with other AM's. The only way to resolve that is allow a dozen or so national AM's blasting 100KW signals across the USA separated enough that they don't step on each other. Don't see any of that being feasible.
Click to expand...

100 kw is low power for any kind of regional coverage. Many directional AMs with 50 kw actually have well in excess of 100 kw in their main lobe; one of the LA stations I am familiar with has nearly 300 kw in such a lobe.

I worked with a 100 kw AM in Buenos Aires on a wonderful low frequency of 710. Still, to get noise-free coverage of the central zone of Bs. As. we had to directionalize to push the equivalent of about 150 kw towards the city. And that is just coverage of one city.

Since little radio listening takes place at night, skywave has been irrelevant for decades. What matters is daytime coverage.

100 kw does not double coverage. It takes four times the power to double coverage. So start thinking of 500 kw to 1 mw to cover individual average size states like Indiana or Kentucky. And then factor in poor conductivity in some... 500 kw in Atlanta covers about the same territory as 50 kw in Omaha.

In any case, who is going to spend the millions needed to create such stations (were the spectrum available)? Radio is a locally bought medium, and no matter what you do on higher power signals today's radios suck on AM, the noise floor is increasing and there is no business model for ad sales.
 
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... It takes four times the power to double coverage. ...
Click to expand...

Running some numbers about this, as an example...

A 1 kW transmit system on 600 kHz with 8 mS/m earth conductivity and generating a 186 mV/m groundwave field at 1 mile will produce a groundwave field of about 2.5 mV/m at a radius of 34.5 miles.

If the transmitter power for the above system is increased by 4X, the 2.5 mV/m radius increases to 49.9 miles.

With 4X the transmitter power the coverage radius increased about 1.45X, and the coverage area increased about 2.09X.
 
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No I don't think processing alone can bring back AM. But I find this topic interesting since I take care of several high power AM sites. One has lots of old documentation. KIRO is ND day 50KW and directional night 50KW. The 50KW site on Vashon was built by Jim Hatfield senior. There was one study done to see if KIRO should run directional day to go east better. I just ran into another study yesterday sitting on the bench ready to be read about adding a 3rd tower at the KIRO transmitter site and going directional day.

Lots of old stuff to read. Just read Hammett & Edison letters from 1976 to 1986. Turns out when the station moved monitor points off of Vashon Island in 1976, after ten years they figured out the tide affected the monitor point. There could be as much as a 10% difference from low to high tide.

While were talking about what could kill or save AM. I take care of 1 NX50, 1 ND50 and three DX50s (5, 50KW stations) and all are great boxes no problems. But three run MDCL and the NX50 is running IBOC with MDCL. I do what my clients ask. Keep them on the air and run the transmitter the way they want it run. Some people say they can hear the when a station is using MDCL. I don't get negative feed back from the stations running MDCL, they like the power savings. When I'm out driving off Island in Seattle and Tacoma I can't tell a difference from when MDCL was turned on for the three stations and I have driven up north to Lynwood, WA and not noticed a difference. Kelly I know you don't like MDCL. And truthfully the only thing I hate about it is setting it up on a Harris transmitter.

My examples of MDCL are 50KW is there a power level that MDCL would have a real negative impact.
 
xmtrland said:
While were talking about what could kill or save AM. Kelly I know you don't like MDCL. And truthfully the only thing I hate about it is setting it up on a Harris transmitter.
Click to expand...

Maybe another reason why Harris DX transmitters sound so much better than Nautel? Kidding! Sort of..

So Steve, are you claiming at MDCL is going to save AM? If so, let me pop some popcorn first.

BTW.. I haven't seen examples of energy savings for a 50kW station running MCDL. There were some purely theoretical claims that seemed pretty sketchy, but wondered by now if there were any documented accounts.
 
stewie said:
Saw this blog post.

Given the source, it's probably good marketing but I was curious if anyone has heard one of these and if it lives up to the hype. With only 5Khz available on most AM radios these days, I don't see how this makes a difference.

Thoughts?

https://blogs.telosalliance.com/when-am-audio-can-run-the-gamut-omnia.7am-is-the-answer
Click to expand...


People are dying to quit listening to AM...literally. Do the old-folks-homes have AM radios? Demographics. AM will likely always be somewhat viable for talk information formats. You don't need a lot of bandwidth for that.

With all of the horrible buck converters in the new LED light bulbs it is getting even harder to get decent S/N ratio unless you are getting a solid daytime carrier level.
 
Old folks often don't know about FM. Young folks have never heard of AM. The really young can't identify with radio...

There is, however, some thinking that the millennials discover free over-the-air FM radio as they mature. AM, not so much. It's interesting that AM Revitalization involves handing out FM translators. How ya gonna keep 'em down on the farm after they've seen Pariee... and heard FM?
 
speakerman said:
People are dying to quit listening to AM...literally. Do the old-folks-homes have AM radios? Demographics.
Click to expand...

My 90-year-old mother listens to her music via her cable music channels. Since adult standards left AM in Phoenix several years ago, she hasn't had a radio turned on at all.

AM will likely always be somewhat viable for talk information formats. You don't need a lot of bandwidth for that.
Click to expand...

Sports hasn't shifted to FM as much as I thought it would have by now. My guess is that there just aren't enough frequencies to cover everything.

With all of the horrible buck converters in the new LED light bulbs it is getting even harder to get decent S/N ratio unless you are getting a solid daytime carrier level.
Click to expand...

I live in a stucco-and-lath encrusted house, typical of what has been built in metro Phoenix for close to 30 years. I get almost no AM reception at all (KTAR 620 is it), unless I take a radio outside, and move it at least 10 feet away from the house.
 
bossbill said:
Old folks often don't know about FM.
Click to expand...

Old folks certainly have heard of FM. It's been around since today's 90-year-olds were in high school. Prior to around 1968, it was "their" band, with classical, jazz, and beautiful music programming all over the dial. But when rock stations came in, those stations aged out and went away over time.

Young folks have never heard of AM.
Click to expand...

Probably not, since rock left the AM band in the 1980s. My generation and those within a few years of us, who were in high school and college in the 1968-82 time frame, were the folks who experienced the move of rock music from AM to FM.

The really young can't identify with radio...
Click to expand...

Not with a majority of all stations on the planet available via TuneIn and other streaming apps. And streaming, despite Mel Karmazin doing his damndest to kill it in the late 1990s, has been around for over 20 years. It's not going away, no matter how much radio sales-holes scream about how it doesn't directly generate revenue. Their bosses don't seem to care, to their credit.
 
TheBigA said:
AFAIC, the only folks who have this romance about AM are DXers.
Click to expand...

Whether it's coal or gas/solar/wind/hydro electric generation, it doesn't matter in case of EMP, according to the designer of the old TEXAR Audio Prism. We might not be using AM, FM, XM or anything else except USM: the US Mail. Read more: http://www.thebdr.net/articles/ops/shop/MS-EMP.pdf

Nothing at all romantic about AM. I don't DX it nearly as much as I used to, mostly because the programming doesn't interest me much today.

Nothing romantic about needing to turn to AM for emergency communications after an EMP event. I don't want to give up the superior technologies that we have available. But after an EMP event, Mr. Clark in the article above feels we may be months if not years reconstructing the electric grid.

It may not be that important to actually save AM radio, because everybody's radios will be fried! There's a vital national interest in keeping AM technology alive however, so we can roll out the emergency AM transmitters out of the bunkers and roll those Quaker Oats crystal sets.

Back from "Doomsday Now!" scenarios, is all-digital modulation on the MW band a possibility in the future, or will it be too flaky?
 
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bossbill said:
Old folks often don't know about FM. Young folks have never heard of AM. The really young can't identify with radio...

There is, however, some thinking that the millennials discover free over-the-air FM radio as they mature. AM, not so much. It's interesting that AM Revitalization involves handing out FM translators. How ya gonna keep 'em down on the farm after they've seen Pariee... and heard FM?
Click to expand...

What's "old" to you? I am over 70 and have been listening to FM since it came on-air in San Francisco in the 60's.

As for listeners....My oldest is 41, youngest is 27 and none of them listen to the radio. My granddaughter is 6 and she doesn't listen to the radio either. I doubt she even knows what radio is. If it isn't on her phone it doesn't exist.
 
joebtsflk1 said:
Back from "Doomsday Now!" scenarios, is all-digital modulation on the MW band a possibility in the future, or will it be too flaky?
Click to expand...

Who owns receivers capable of "digital AM?" Do you really think people are going to run out and buy digital AM radios?
 
TheBigA said:
Who owns receivers capable of "digital AM?" Do you really think people are going to run out and buy digital AM radios?
Click to expand...

Now, no. In the future, after audience erosion on the AM band becomes nearly complete, those remaining stations on 540 - 1700 might elect to use digital modulation.

Then again, gambling on digital MW to eventually be the next big thing means maintaining a multi-tower transmitter site for most stations of any size. Easy enough back in the day to hang a few bays on an existing tower and preserve a marker on the FM band. Keeping a 4 tower DA....hmmmm?
 
joebtsflk1 said:
Now, no. In the future, after audience erosion on the AM band becomes nearly complete, those remaining stations on 540 - 1700 might elect to use digital modulation.
Click to expand...

But for it to happen, over 300 million people will need to replace their analog radios. Why would they do that if they can already receive digital radio on their phone?

What the FCC has designated in their "AM revitalization" is for those AM stations to move to FM translators. Problem solved.
 
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