‘NO PROBLEM with good ‘ole-fashioned AM!

[Kelly]

When I was a kid I would listen to anything that played what I wanted to hear, that still holds true today. There was one progressive AM station here in Newton MA on 1550. It came in terrible here in Worcester being I think a 1 Kw station but whenever I drove out near Boston it was on in my car and I was a die hard WBCN listener by that point having migrated from AM several years earlier because of the programming, no other reason, in fact I thought the FM mode was inferior as it had no skywave. I even listened to it at home sometimes. My point being that if the type of programming that kids want is on AM radio they'll listen. The pre-teens listen to Radio Kidney don't they? I don't think AM is dieing either, it's main problem right now besides consolidated boring programming and virtually no music is that it is under assault from new powerful self-inflicted noise generators strategically placed through out the band. AM would be good for niche programming, 50's oldies, blues, real jazz, Reggae, etc. The former CHWO 740 plays all kinds of niche type music and is very successful at it. I was listening to Big Band Saturday Night on CHWO last night for example.
[/quote]

Well I for one really have enjoyed yet another trip in the old "wayback machine" there KB, but can you take a moment and rejoin the rest of us here in the 21st century for a moment? Thanks.

First of all, back in what is now considered "the old days", AM radio was the only game in town. Much of the timeless music came out highly compressed and distorted out of the Medium Wave band. Then in the 70's FM came around as the "underground" medium for music! You didn't lose an FM broadcasts in tunnels, neon signs and high tension power lines didn't almost blow out your car speaker with loud noise, and there were minimal commercial interruptions.

Fast forward to modern times...The same demographics that switched away from AM to FM back in the early 70's to hear their music, are now downloading it off the Internet, and creating their OWN playlists depending on the mood. Gone are the days of yakky DJ's, commercial sets that seem to go on and on. Gone is the noise when going under a noisy pole-hog in the neighborhood that would blow your eardrums if you were wearing earbuds, or frequency response that sounds like it's coming from behind a moving blanket. And gone is over-processed audio with stereo separation that is not an exact copy of what was on the original master recording. Really when you stop to think about it, all the same motivations that caused FM to become the medium of choice for music listening, is even moreso with portable devices and soon live streaming off the Net.

It's great that you have all these memories KB. I have them too. The difference between us, and the majority of consumers I would argue, is that most of us choose to follow the times, rather than live in the past thinking everyone should do the same. Also I suspect that the combination of you having not worked in the broadcast industry, with your love for the hobby of DXing sometimes clouds perception. But that's okay KB, feel free to use your technical skills and invent a time machine that will take us all back to the glory days of swing and dance tunes on AM radio. The rest of us will be over here in the 21st century enjoying the latest forms of media, while trying to run a business.

 

[Carmine5]

Frankly, I am sick and tired of the hackneyed "AM is Dead" mindset. This is the mantra of uninspired and uninspiring programmers, station owners, and people who claim to be friends of radio but aren't.

If you worked at an AM station in 1983, as I did, you'd realize that there's NOTHING you can do as a programmer that will return AM radio to its former glory. That train left the station a long time ago. You can bring back Boss Radio, Robert W. Morgan, and all the legends who made AM radio great, and even THEY would fall flat on their faces. Lots of very smart and creative people have tried during the last 25 years, they've spent hundreds of millions of dollars, and ended up with hangover.

It was unanimous. They all said, "yes." That's right. They would listen to AM, with all its pops, buzzes and hiss, if the programming interested them.

They're full of crap. Most of them don't even OWN an AM radio, and wouldn't buy one if it cost $10. Regardless of the programming. I could broadcast live sex on AM and people under 30 wouldn't listen. Unless the sex involves them directly, they're not interested. If they're female, it wouldn't even matter if they're involved.

Bottom line? It is third rate, cheap, uninspired programming and the 'AM is dead' mindset that is killing AM for the under 30 crowd, not environmental noise.

Until this thinking changes, then yes, AM is dying.

I can direct you to a 5K AM station in a Top 20 market right now for less money than a cheap house. $10K down, and monthly payments of about $3000. Would you put your own cash money into it? I bet you wouldn't.

Email me if you have the guts. Otherwise STFU.

In case you hadn't heard, there is such a thing as an AM/FM radio. They're in cars, clock and table radios and receivers. So, yes, I would say these young people have AM somewhere in their possession. They won't go out and buy an AM only radio (if one can even be found) but I have no doubt they have AM.

I don't need to e-mail you and, yes, I have the guts. I'm already investing in an AM station, so save it for someone else.

C5

 

[Kelly]

Super! What's the format? Will you be changing the format to Reggae soon?

 

[pocket-radio]

Re: ‘NO PROBLEM with good ‘ole-fashioned AM!

I haven't seen any major change in AM ratings as a result of IBOC. The people who were going to switch to FM already did it a long time ago. And if you can't get Rush or 24/7 news on an FM station in your market, then switching to FM is not an option.

I haven't seen ANY ratings Am or Fm Iboc. I agree with BigA Rush keeps listeners on Am if an Fm option isn't available.

 

[KB1OKL]

When I was a kid I would listen to anything that played what I wanted to hear, that still holds true today. There was one progressive AM station here in Newton MA on 1550. It came in terrible here in Worcester being I think a 1 Kw station but whenever I drove out near Boston it was on in my car and I was a die hard WBCN listener by that point having migrated from AM several years earlier because of the programming, no other reason, in fact I thought the FM mode was inferior as it had no skywave. I even listened to it at home sometimes. My point being that if the type of programming that kids want is on AM radio they'll listen. The pre-teens listen to Radio Kidney don't they? I don't think AM is dieing either, it's main problem right now besides consolidated boring programming and virtually no music is that it is under assault from new powerful self-inflicted noise generators strategically placed through out the band. AM would be good for niche programming, 50's oldies, blues, real jazz, Reggae, etc. The former CHWO 740 plays all kinds of niche type music and is very successful at it. I was listening to Big Band Saturday Night on CHWO last night for example.

Well I for one really have enjoyed yet another trip in the old "wayback machine" there KB, but can you take a moment and rejoin the rest of us here in the 21st century for a moment? Thanks.

First of all, back in what is now considered "the old days", AM radio was the only game in town. Much of the timeless music came out highly compressed and distorted out of the Medium Wave band. Then in the 70's FM came around as the "underground" medium for music! You didn't lose an FM broadcasts in tunnels, neon signs and high tension power lines didn't almost blow out your car speaker with loud noise, and there were minimal commercial interruptions.

Fast forward to modern times...The same demographics that switched away from AM to FM back in the early 70's to hear their music, are now downloading it off the Internet, and creating their OWN playlists depending on the mood. Gone are the days of yakky DJ's, commercial sets that seem to go on and on. Gone is the noise when going under a noisy pole-hog in the neighborhood that would blow your eardrums if you were wearing earbuds, or frequency response that sounds like it's coming from behind a moving blanket. And gone is over-processed audio with stereo separation that is not an exact copy of what was on the original master recording. Really when you stop to think about it, all the same motivations that caused FM to become the medium of choice for music listening, is even moreso with portable devices and soon live streaming off the Net.

It's great that you have all these memories KB. I have them too. The difference between us, and the majority of consumers I would argue, is that most of us choose to follow the times, rather than live in the past thinking everyone should do the same. Also I suspect that the combination of you having not worked in the broadcast industry, with your love for the hobby of DXing sometimes clouds perception. But that's okay KB, feel free to use your technical skills and invent a time machine that will take us all back to the glory days of swing and dance tunes on AM radio. The rest of us will be over here in the 21st century enjoying the latest forms of media, while trying to run a business.


[/quote]

Again you missed my point, which is: if the music and programming is there, the kids will listen to it, if they'll listen to lo-fi MP3's they'll certainly listen to AM radio. AM radio has something that FM nor AM IBOC has: (except of course for the whooshy sidebands which seem to go around the globe, even to Australia ;D and that thing is: skywave.

Now read this slowly ,perhaps a few times and you'll understand it.

And I hope you now see that your 4 Khz top end on AM radio is total baloney except for iBlock stations which have to use it. Maybe you ought to get out a little more into the real world there yourself?

 

[Kelly]

Here KB, let me help you before you look more foolish.. Oh and just so you are clear, the following technical facts have nothing to do with IBOC/HD radio..

The FCC/NRSC required occupied bandwidth of Domestic AM Medium Wave stations is 10.2Khz. As even Bruce pointed out, for good or bad, 99% of the auto and portable radios that are AM and FM have a narrow IF filter to increase sensitivity and reduce noise. That, combined with audio filtering to reduce HF splatter mean the average high frequency response of a consumer tuner is 3.2-4.5Khz, not 10.2Khz. Don't believe me? Then go measure a few with a good test set like an Audio Precision. Heck even my restored antique tube radios such as my Magnavox 1528 from 1946 only passes high frequencies in audio out to 6Khz, and it's been completely re-capped and has all new tubes.

On more than one occasion, you stated that you believed that many stations were not operating within the FCC emission standards, (NRSC), as specified in the Radio and Television Broadcast Rules 47 CFR Part 73, 73.44 AM transmission system emission limitations, paragraph (b), and, to the best of your knowledge, (which appears to be clearly limited at best), were disregarding the requirement. So, based on your comments, I would argue that once again, you don't know what you're talking about. In an effort to educate you with the actual rule, I have taken the liberty of adding it to this reply:

(b) Emissions 10.2 kHz to 20 kHz removed
from the carrier must be attenuated
at least 25 dB below the
unmodulated carrier level, emissions 20
kHz to 30 kHz removed from the carrier
must be attenuated at least 35 dB
below the unmodulated carrier level,
emissions 30 kHz to 60 kHz removed
from the carrier must be attenuated at
least [5 + 1 dB/kHz] below the
unmodulated carrier level, and emissions
between 60 kHz and 75 kHz of the
carrier frequency must be attenuated
at least 65 dB below the unmodulated
carrier level. Emissions removed by
more than 75 kHz must be attenuated
at least 43 + 10 Log (Power in watts) or
80 dB below the unmodulated carrier
level, whichever is the lesser attenuation,
except for transmitters having
power less than 158 watts, where the attenuation
must be at least 65 dB below
carrier level.

So you see KB, the bandwidth limitation on the transmit side is a rule, not an option. You can once again be in denial by claiming some broadcasters don't follow the rules, and maybe you're right. I certainly hope that you as a proud licensed HAM don't think operating outside the rules are okay!

 

[Play Freebird]

The FCC/NRSC required occupied bandwidth of Domestic AM Medium Wave stations is 10.2Khz. As even Bruce pointed out, for good or bad, 99% of the auto and portable radios that are AM and FM have a narrow IF filter to increase sensitivity and reduce noise. That, combined with audio filtering to reduce HF splatter mean the average high frequency response of a consumer tuner is 3.2-4.5Khz, not 10.2Khz. Don't believe me? Then go measure a few with a good test set like an Audio Precision. Heck even my restored antique tube radios such as my Magnavox 1528 from 1946 only passes high frequencies in audio out to 6Khz, and it's been completely re-capped and has all new tubes.

On more than one occasion, you stated that you believed that many stations were not operating within the FCC emission standards, (NRSC), as specified in the Radio and Television Broadcast Rules 47 CFR Part 73, 73.44 AM transmission system emission limitations, paragraph (b), and, to the best of your knowledge, (which appears to be clearly limited at best), were disregarding the requirement. So, based on your comments, I would argue that once again, you don't know what you're talking about. In an effort to educate you with the actual rule, I have taken the liberty of adding it to this reply:

(b) Emissions 10.2 kHz to 20 kHz removed
from the carrier must be attenuated
at least 25 dB below the
unmodulated carrier level,....

If I may add a correction to your last post, the RF occupied bandwidth would actually be closer to 20.4 kHz, because emissions out to +/- 10.2 kHz from the carrier aren't required to be attenuated and there are two sidebands. If we're just talking about audio, you are correct that the high end response is sharply limited past 10.2 kHz, and the response of consumer receivers is all over the place. (This reminds me, I need to run my annual NRSC proof within the next couple of months!)

I think the point that Hippo and KB were trying to make is that it's not impossible to design an AM receiver that offers better than 3 or 4 kHz audio bandwidth. I have a 1960 Stromberg Carlson console radio with a "HI FI" AM setting that's quite flat out to 9 kHz (it includes a 10 k LC notch filter).

Manufacturers have been taking the easy and cheap way out for years with the narrow ceramic filters, but we now have new techniques like DSP that could allow dynamic variable bandwidth and notch-filtering of the 10 kHz whistle. As receivers move towards a software-defined platform, the cost of DSP chips will drop, allowing the promise of better AM performance at minimal expense. But as long as AM IBOC exists, with its hash bands extending from 5 to 15 kHz each side of the AM carrier, this noise will discourage receiver manufacturers from even trying.

 

[Carmine5]

Super! What's the format? Will you be changing the format to Reggae soon?

No, I just cited Reggae as an example. I have no idea what the format will be, or if my partner and I will finish building it or, if we build it, if we'll keep it. Right now it's tower site issues and tight credit. We just have a CP with three years to build.

C5

 

[Kelly]

Good point Play, and you're right. I was making the point that the audio response ends at 10.2Khz. Like you, I need to make the trek out to my one single AM station about 280 miles from where I live and do my yearly proof as well. Then time to send the ol' HP spectrum analyzer out for calibration this year too.

I'm sure there are very rare exceptions of extended frequency response in receivers, but they are not in the mainstream of consumer electronics by any means. Until someone here is able to step up and show me examples of modern mainstream AM/FM radios that have high frequency audio response above 4.5Khz, then they completely lack credibility on the subject. That being said, I'm always open to being proven wrong in a fair and technically accurate debate.

Heck, I even measured the outputs of my 98 Jeep XJ radio (with AM stereo capabilites), thinking it would have a pretty good audio response, but was disapointed to see 3.8Khz was down >24db, and completely gone at 4.2Khz. I made the measurements as real-world as I could by using a borrowed White Instruments audio spectrum analyzer with a peak and hold. I tried three different local AM stations not running IBOC, or the reduced NRSC curve. In all cases the high frequency response never exceeded 4Khz. Just to make sure my measurements were valid, I calibrated the White Instruments unit with pink, then white noise to make sure the bandpass was dead-on flat. My audio tap was from the front left and right speaker feeds, connected to a matching transformer matching from 8 ohms at the radio amp side, to 600 ohms secondary on the test equipment side. The idea being I didn't want impedance mismatches to cause equalization issues in the measurements.

Frankly I don't hold out much hope for consumer electronics manufacturers improving on AM demodulation technology, even with the advances in software. In fact, when at the Consumer Electronics Show this past January, Visteon (Ford), was showing some of their new advanced automotive entertainment units in a Ford Mustang, Focus, Expedition, and a wonderful, (aka I want one..), Alfa Romeo 8C. None of the new systems shown at the booth even had an AM tuner built in! The shape of things to come for AM? Could be!

 

[Kelly]

Super! What's the format? Will you be changing the format to Reggae soon?

No, I just cited Reggae as an example. I have no idea what the format will be, or if my partner and I will finish building it or, if we build it, if we'll keep it. Right now it's tower site issues and tight credit. We just have a CP with three years to build.

C5

Then I wish you well on the project. Having built and purchased my fair share of AM's FM's and TV's in my day, any one or all of the issues you mentioned can keep one awake at night.

So other than your informal poll with some co-workers, or whomever you mentioned, are you planning on doing any audience research prior to determining a format? What other formats are there on AM's in the market? What part of the country is the CP located?

Rest assured I'm not asking because I want to beat you up, on the contrary, I'm just curious to see what it's like to actually build and market a new AM when listenership is trending down as the 20-something generation ignores the band. I'd also be interested in knowing what formats you're considering, and how you came to the consideration.

 

[rbrucecarter5]

As even Bruce pointed out, for good or bad, 99% of the auto and portable radios that are AM and FM have a narrow IF filter to increase sensitivity and reduce noise.

WRONG! 99% of AM radios manufactured today either put everything including IF into a single DSP chip, or the cheapies use an analog chip that has ONE ceramic filter AM, and one ceramic filter FM. A while back, someone named Shredderman posted extensive pictures of a dozen of those cheapies.

The ceramic filters are NOT narrowband - Shredderman claimed +/-40 kHz out of an AM filter that was barely even attenuating the stop bands, and I think another AM radio that omitted the ceramic filter completely and just used a ceramic capacitor. That's not even a superhet design any more, and the only selectivity would come from the ferrite antenna and tuning cap! Glorified crystal radio.

Of course the crystal radio enthusiasts have been enjoying wideband AM for years, and know how good it can sound when properly engineered. But selectivity? Very wide. And if Shredderman was right and really had +/-40 kHz audio bandwidth on an AM radio, then the cheaper a ceramic filter, the less selectivity it puts into the radio. Sheesh - if +/-40 kHz is right - then any HD station is going to sound like a hash fest! AWFUL engineering, cheaply slapped together, probably barely better on FM. THAT is AM FM radio to most people, because the radio is an afterthought in a clock radio, a flashlight radio, an iPod dock, a surround sound system, or whatever else it is they bought. Probably the only decent radios left are in cars, and how long is that going to last? I know for a FACT that they are downgrading AM sections to be less sensitive so they don't pick up interference from DVD players. And the company I talked to was doing that 5 years ago!!! By now - AM is an afterthought in car radios, it if hasn't already been for 30 years.

So in today's reality - does the technical idea of using sidebands for AM IBOC even make sense? They are going to come through cheap wideband ceramic filters. The mechanical lash of the tuning mechanism makes it impossible to get on frequency, so even the phase modulated 5 to 10 kHz sidebands are going to be heard - LOUD. And that is assuming there is any sore of symmetry in those trashy wide ceramic filters that are barely there. I love to hold of Shredderman's +/- 40 kHz filter and analyze it, I bet the response is lumpy and horrific, which would also not be good at cancelling phase modulated HD sidebands.

 

[Carmine5]

Frankly, I am sick and tired of the hackneyed "AM is Dead" mindset. This is the mantra of uninspired and uninspiring programmers, station owners, and people who claim to be friends of radio but aren't.

Two months ago, my good friend and business partner and I did an informal survey at our places of work. He on the East Coast, me on the West Coast. We each asked 10 people under 30 what their impression of AM was. Answer: News, Talk, Sports--news, talk, sports--news, talk, sports. Most of the guys said they listened to AM for sports and news. About 20% of the women said they listened to news. Nobody but nobody said they listened to talk. Rush Limbaugh, Michael Savage and Sean Hannity are dead, dead, dead with the under 30 crowd.

Next, we asked that if there was a format they really wanted to hear but could only get on AM, like Reggae, would they tune in and listen. It was unanimous. They all said, "yes." That's right. They would listen to AM, with all its pops, buzzes and hiss, if the programming interested them.

Bottom line? It is third rate, cheap, uninspired programming and the 'AM is dead' mindset that is killing AM for the under 30 crowd, not environmental noise.

Until this thinking changes, then yes, AM is dying.

C5

When I was a kid I would listen to anything that played what I wanted to hear, that still holds true today. There was one progressive AM station here in Newton MA on 1550. It came in terrible here in Worcester being I think a 1 Kw station but whenever I drove out near Boston it was on in my car and I was a die hard WBCN listener by that point having migrated from AM several years earlier because of the programming, no other reason, in fact I thought the FM mode was inferior as it had no skywave. I even listened to it at home sometimes. My point being that if the type of programming that kids want is on AM radio they'll listen. The pre-teens listen to Radio Kidney don't they? I don't think AM is dieing either, it's main problem right now besides consolidated boring programming and virtually no music is that it is under assault from new powerful self-inflicted noise generators strategically placed through out the band. AM would be good for niche programming, 50's oldies, blues, real jazz, Reggae, etc. The former CHWO 740 plays all kinds of niche type music and is very successful at it. I was listening to Big Band Saturday Night on CHWO last night for example.

Yes, like you KB, I have a lot of great memories with AM. But I'm also trying not to live in the past, particularly as I try to build a small market station for the next generation.

This doesn't mean that I won't program older music. As it turns out, many of today's teens are discovering and getting into rockabilly and surf music.

But, as you said, I think niche programming can work very well for AM. Leave the mainstream formats and tight playlists to FM.

One thing I would like to do, is offer a Sunday night segment in which local bands, garage band even (if they're good), can showcase their music. I think kids would love hearing themselves and their friends on the air. Old kids, like myself, would be welcomed too. The idea is to come up with something fresh, generate some enthusiasm with the locals while using an old medium.

BTW, I'm not saying that I think AM is fine as it is. I definitely would like to see an improvement in audio quality. Maybe digital--but not HD. For now, though, I think crafting the best analog signal possible would go a long way in helping AM's image.

C5

 

[Kelly]

As even Bruce pointed out, for good or bad, 99% of the auto and portable radios that are AM and FM have a narrow IF filter to increase sensitivity and reduce noise.

WRONG! 99% of AM radios manufactured today either put everything including IF into a single DSP chip, or the cheapies use an analog chip that has ONE ceramic filter AM, and one ceramic filter FM. A while back, someone named Shredderman posted extensive pictures of a dozen of those cheapies.

The ceramic filters are NOT narrowband - Shredderman claimed +/-40 kHz out of an AM filter that was barely even attenuating the stop bands, and I think another AM radio that omitted the ceramic filter completely and just used a ceramic capacitor. That's not even a superhet design any more, and the only selectivity would come from the ferrite antenna and tuning cap! Glorified crystal radio.

Of course the crystal radio enthusiasts have been enjoying wideband AM for years, and know how good it can sound when properly engineered. But selectivity? Very wide. And if Shredderman was right and really had +/-40 kHz audio bandwidth on an AM radio, then the cheaper a ceramic filter, the less selectivity it puts into the radio. Sheesh - if +/-40 kHz is right - then any HD station is going to sound like a hash fest! AWFUL engineering, cheaply slapped together, probably barely better on FM. THAT is AM FM radio to most people, because the radio is an afterthought in a clock radio, a flashlight radio, an iPod dock, a surround sound system, or whatever else it is they bought. Probably the only decent radios left are in cars, and how long is that going to last? I know for a FACT that they are downgrading AM sections to be less sensitive so they don't pick up interference from DVD players. And the company I talked to was doing that 5 years ago!!! By now - AM is an afterthought in car radios, it if hasn't already been for 30 years.

So in today's reality - does the technical idea of using sidebands for AM IBOC even make sense? They are going to come through cheap wideband ceramic filters. The mechanical lash of the tuning mechanism makes it impossible to get on frequency, so even the phase modulated 5 to 10 kHz sidebands are going to be heard - LOUD. And that is assuming there is any sore of symmetry in those trashy wide ceramic filters that are barely there. I love to hold of Shredderman's +/- 40 kHz filter and analyze it, I bet the response is lumpy and horrific, which would also not be good at cancelling phase modulated HD sidebands.

Uh...okay then Bruce, so am I intrepreting your comment "WRONG" that there aren't narrow IF filters in modern radios? It seems like that's exactly what you're saying, or are you? Whether derrived in a chip/firmware, or with discrete components, I would argue, (or am I), that the narrow IF strips in AM demodulator circuits is part of the problem with modern AM tuners.

 

[TheBigA]

It's ironic how you fault (and name-call) the "Anti-IBOC brigade" over an alleged rumour which YOU apparently started.

I didn't say it to start a rumor. I certainly never expected to see it quoted in another blog as though what I say is representative of something. But that's how things go today. I should copyright my stuff. Some people do.

 

[Kelly]

Unfortunately some of the regulars on this board will jump on anything negative regarding IBOC like flies on you-know-what. Some also confuse blog posts as articles from reliable sources. That is of course if it agrees with their point of view.

The least they could have done is attribute the comment to you. Hmm... I wonder if Radio-Info pays publishing royalties?

 

[TheBigA]

The least they could have done is attribute the comment to you.

From what I've seen, most of the blogosphere is not about attribution.

 

[Carmine5]

Super! What's the format? Will you be changing the format to Reggae soon?

No, I just cited Reggae as an example. I have no idea what the format will be, or if my partner and I will finish building it or, if we build it, if we'll keep it. Right now it's tower site issues and tight credit. We just have a CP with three years to build.

C5

Then I wish you well on the project. Having built and purchased my fair share of AM's FM's and TV's in my day, any one or all of the issues you mentioned can keep one awake at night.

So other than your informal poll with some co-workers, or whomever you mentioned, are you planning on doing any audience research prior to determining a format? What other formats are there on AM's in the market? What part of the country is the CP located?

Rest assured I'm not asking because I want to beat you up, on the contrary, I'm just curious to see what it's like to actually build and market a new AM when listenership is trending down as the 20-something generation ignores the band. I'd also be interested in knowing what formats you're considering, and how you came to the consideration.

The informal survey was just to prove to ourselves that AM, in of and by itself, is not a turn off to the under 30 crowd.

The CP is for a city in No. CA. There are a few format "holes" that could be filled there. The existing AM's are doing the usual 3 formats; sports/talk/news. Oh, there is one religious AM. From what I can ascertain, most of the stations are grossing in the six figures.

Although, we've done some internet-based research on the community, we will be going up there next month to check the area out for ourselves. I have no idea, for example, if the area can sustain another radio station, particularly AM.

It's too soon, at this point, to say what will work or if we will even build the station. We may just try to secure a tower site and sell the CP that way. I'll know more next month.

C5

 

[KB1OKL]

The FCC/NRSC required occupied bandwidth of Domestic AM Medium Wave stations is 10.2Khz. As even Bruce pointed out, for good or bad, 99% of the auto and portable radios that are AM and FM have a narrow IF filter to increase sensitivity and reduce noise. That, combined with audio filtering to reduce HF splatter mean the average high frequency response of a consumer tuner is 3.2-4.5Khz, not 10.2Khz. Don't believe me? Then go measure a few with a good test set like an Audio Precision. Heck even my restored antique tube radios such as my Magnavox 1528 from 1946 only passes high frequencies in audio out to 6Khz, and it's been completely re-capped and has all new tubes.

On more than one occasion, you stated that you believed that many stations were not operating within the FCC emission standards, (NRSC), as specified in the Radio and Television Broadcast Rules 47 CFR Part 73, 73.44 AM transmission system emission limitations, paragraph (b), and, to the best of your knowledge, (which appears to be clearly limited at best), were disregarding the requirement. So, based on your comments, I would argue that once again, you don't know what you're talking about. In an effort to educate you with the actual rule, I have taken the liberty of adding it to this reply:

(b) Emissions 10.2 kHz to 20 kHz removed
from the carrier must be attenuated
at least 25 dB below the
unmodulated carrier level,....

If I may add a correction to your last post, the RF occupied bandwidth would actually be closer to 20.4 kHz, because emissions out to +/- 10.2 kHz from the carrier aren't required to be attenuated and there are two sidebands. If we're just talking about audio, you are correct that the high end response is sharply limited past 10.2 kHz, and the response of consumer receivers is all over the place. (This reminds me, I need to run my annual NRSC proof within the next couple of months!)

I think the point that Hippo and KB were trying to make is that it's not impossible to design an AM receiver that offers better than 3 or 4 kHz audio bandwidth. I have a 1960 Stromberg Carlson console radio with a "HI FI" AM setting that's quite flat out to 9 kHz (it includes a 10 k LC notch filter).

Manufacturers have been taking the easy and cheap way out for years with the narrow ceramic filters, but we now have new techniques like DSP that could allow dynamic variable bandwidth and notch-filtering of the 10 kHz whistle. As receivers move towards a software-defined platform, the cost of DSP chips will drop, allowing the promise of better AM performance at minimal expense. But as long as AM IBOC exists, with its hash bands extending from 5 to 15 kHz each side of the AM carrier, this noise will discourage receiver manufacturers from even trying.

Yes and I would be willing to bet that most consumers would not hear much of a difference between 10.2 Khz and 15 khz, that is less than one octave in musical terms and contains mostly sibilant overtones and many people our age are lucky to still be able to hear up to 15K. I have several wideband receivers here not the least of is the Meduci and although they may not be many wideband stations broadcasting, there are some and they sound great through these receivers,and the Meduci sounds the best.

 

[KB1OKL]

As even Bruce pointed out, for good or bad, 99% of the auto and portable radios that are AM and FM have a narrow IF filter to increase sensitivity and reduce noise.

WRONG! 99% of AM radios manufactured today either put everything including IF into a single DSP chip, or the cheapies use an analog chip that has ONE ceramic filter AM, and one ceramic filter FM. A while back, someone named Shredderman posted extensive pictures of a dozen of those cheapies.

The ceramic filters are NOT narrowband - Shredderman claimed +/-40 kHz out of an AM filter that was barely even attenuating the stop bands, and I think another AM radio that omitted the ceramic filter completely and just used a ceramic capacitor. That's not even a superhet design any more, and the only selectivity would come from the ferrite antenna and tuning cap! Glorified crystal radio.

Of course the crystal radio enthusiasts have been enjoying wideband AM for years, and know how good it can sound when properly engineered. But selectivity? Very wide. And if Shredderman was right and really had +/-40 kHz audio bandwidth on an AM radio, then the cheaper a ceramic filter, the less selectivity it puts into the radio. Sheesh - if +/-40 kHz is right - then any HD station is going to sound like a hash fest! AWFUL engineering, cheaply slapped together, probably barely better on FM. THAT is AM FM radio to most people, because the radio is an afterthought in a clock radio, a flashlight radio, an iPod dock, a surround sound system, or whatever else it is they bought. Probably the only decent radios left are in cars, and how long is that going to last? I know for a FACT that they are downgrading AM sections to be less sensitive so they don't pick up interference from DVD players. And the company I talked to was doing that 5 years ago!!! By now - AM is an afterthought in car radios, it if hasn't already been for 30 years.

So in today's reality - does the technical idea of using sidebands for AM IBOC even make sense? They are going to come through cheap wideband ceramic filters. The mechanical lash of the tuning mechanism makes it impossible to get on frequency, so even the phase modulated 5 to 10 kHz sidebands are going to be heard - LOUD. And that is assuming there is any sore of symmetry in those trashy wide ceramic filters that are barely there. I love to hold of Shredderman's +/- 40 kHz filter and analyze it, I bet the response is lumpy and horrific, which would also not be good at cancelling phase modulated HD sidebands.

Uh...okay then Bruce, so am I intrepreting your comment "WRONG" that there aren't narrow IF filters in modern radios? It seems like that's exactly what you're saying, or are you? Whether derrived in a chip/firmware, or with discrete components, I would argue, (or am I), that the narrow IF strips in AM demodulator circuits is part of the problem with modern AM tuners.

What he is saying is that with modern radios, the cheapies as he puts it, either have extremely wide ceramic filters or have no filters at all. I have little or no experience with these radios and probably won't. I have several very good ones with wide position 16 Khz filters in them and they are too wide to only pick up one station on the AM band with close adjacent's especially at night. The widest practical filter I have is 8 Khz. The 16 Khz does sound great though when there are no locals or IBOC stations near the one being received, and yes crystal radios sound great, they are the most pure sound you can get