ANOTHER BIG HD-AM PLUS: IT COULD BLOW UP YOUR TRANSMITTER!

[Dighton Rockhead]

The HD cartel's new promo?
HD Radio - It's smokin'

Of course!!......It must be a reference to those power-hungry circuits in those HD radios overheating. ;D ;D ;D

 

[calstymes]

LinoNYC observed:

radio engineering is very fraternal, if this were an issue, no one, not even the "iboc powers that be" could "forcibly hush this bunch.

Really. You don't think so? There are several people who are posting on this here message board who have elected to keep their identities masked so as not to incur any backlash if they were discovered to be speaking out against a technology that has been adopted by their employers. But I digress...

This is all about the public offering. This whole thing is about the public offering. There is too much at stake now and it MUST happen for iBiquity, otherwise, some people are going to be in an awful lot of financial trouble.

Follow the money.

 

[Tom Wells]

I love the smell of toasted silicon in the morning.

 

[JohnnyElectron]

WWJ fixed their 50KW buzzbomb and it's back on the air from 930-970KHz, but WWWM-FM hasn't had their IBOC on air for almost 2 years now - pretty expensive to pay iBiquity for something that's sitting-around doing nothing (iBiquity finally just took them off their list).

 

[vsa]

LinoNYC observed:

radio engineering is very fraternal, if this were an issue, no one, not even the "iboc powers that be" could "forcibly hush this bunch.

...This is all about the public offering.  This whole thing is about the public offering.  There is too much at stake now and it MUST happen for iBiquity, otherwise, some people are going to be in an awful lot of financial trouble.

Follow the money.

With the IPO in iBiquity stock, I expect to actually see some upside price action, powered by a huge short squeeze. Once all of the retail investor shorts are forced to cover, the stock will come crashing down faster than you can say Bear Strearns.   ;D

 

[KB1OKL]

And once again I say AM sounds wonderful.

The radios that the masses have accquired in the last 20 years,
along with the interference - spewing junk still somehow permitted in direct defiance of pt 15 unintentional radiator rules
have given people the impression that AM sounds bad. General Motors Deldo-Delphi is THE prominent perpetrator of this,
selling cars radios with the AM so gagged that it is often impossible to distinguish words clearly.

Even the nicest furniture in the world shows poorly in a pig-stye.
And it doesn't matter whether it's digital or analog furniture, it's going to get mud and pig-waste on it.


With so much RF interference being generated locally, few people are going have luck with AM HD.
The failure of the FCC to regulate the MW band's viablility by enforcing existing rules is THE reason AM is hampered.
A sane FCC would have not even permittted the mud-box Delcos to be built and sold to the public.
As unintelligible as they are, they are a public nuisance. They'd make good communications receivers for SW or MW dx if
they had proper front ends, which they don't, so they're not worth listening to.

I know when I have a GM rental car, I don't listen to AM. It's too maddening.
I dream of yanking the radio, and finding some way to shunt the dang ceramic filter with a cap.
If I do tune around and find a local so strong they "walk through" the MW tuner, they sound wonderful if you listen
50 khz or so off freq, because it gets around the 2.5 khz brickwall.

We need a board for "Let's get this mess cleaned up!", where RF interference could be reported, along with measures taken to
mitigate the noise. In fact there should be two such boards, one for in-home sources, and another for "external sources".

Interference made by man is preventable and curable.
I reject arguments that we should just live with it, and/or develop technologies creating EVEN more noise in an attempt to
shout over the noise. Even if you get it to work today, why would you think tomorrows noise is not going to be worse?

What will the be solution then? Another 10db of square wave noise? Isn't this already being suggested?
Where does this end?

More blame and discussion about the old days...great.

Tell you what Tom, go ask a 15 year old whether they care about AM radio. Better yet, ask them how it sounds, assuming they even know what AM radio is. As much as you would like to relive the past, they are the future.

If you're okay with allowing radio to just fade away like your memories of the "good ol' hi-fi days" of AM with 40% distortion, that's super. What a waste!

I'm listening to CHWO 740 AM, Toronto, Canada on a 1941 Hallicrafters SX-28 hooked to a 8" coaxial speaker in a sealed box. This radio puts out 8 watts of hifi push pull tube audio and has a 12 Khz front end in wide mode. They're playing swing, oldies, jazz, jump, it's a show called Saturday Night Jive. The fidelity is good, the music is good and yes AM sounds wonderful. I'm 15 (+40).

 

[Savage]

I don't know what station Kelly was listening to back in "the good old days of hi-fi AM radio" where he was hearing 40% distortion. Maybe the stations he engineered sounded like that, but none I every worked for - or owned - did. Not even with asymmetrical 99%- and 125% positive modulation.

I did, on the other hand, work at stations like CKLW and WELM which offered 13 kHz (or better) bandpass, and I have high-quality airchecks of those stations which sound better than anything on AM or FM offered today - even on today's much-maligned receivers.

The "HD is the only hope for radio" continues to be a ridiculous and indefensible argument being forcibly pressed by a dogmatic few, with an obvious personal agenda.

 

[tripinva]

As someone who's not old enough to have experienced high-quality AM, would you be willing to post some samples of this online? I'd be curious to hear what they sound like.

Thanks.

- Trip

 

[Savage]

Sure, Trip - go to www.wysl1040.com. Click on "You Don't Need HD-AM" on the right-hand column link, scroll to the bottom, and there's an mp3 file of WELM recorded right off-air in October 1971. Tx was an RCA BTA-1R, Audimax-Volumax single-channel processing, recorded off the audio detector of a General Radio modulation monitor. The audio you hear is straight from an open-reel 7.5 ips recording of the air signal.

I'll have to get some CKLW audio up there....only reason I haven't is that most of the 1973 airchecks I have are 'scoped - but I should be able to find some excerpts where I had the mic on long enough to give you a good taste of the sound quality. Ed Buterbaugh was - and is - truly a genius.

 

[RememberWHEN]

Savage - I am in your camp as far as AM-HD. Period. It trashes up the band and muzzles the analog audio of anybody "brave" enough to implement IBOC on their station.

Having stated that, your mp3 was very painful to listen to. The artifacts from the single channel processing make that file extremely difficult to appreciate the sonic message you are trying to convey. I'd get that off the site and replace it with CKLW material, 'scoped or not, as soon as you could. It most certainly doesn't showcase what AM is capable of. Off air, and hundreds of miles away in Northern Indiana, the CKLW audio signature it it's Top 40 heyday was truly astounding. It sounded nothing like that clip. There has got to be a better sample available. I'm afraid someone listening to that file will 'walk away' from the experience convinced that music on AM is something that just shouldn't be done. We both know that is not the case. I do appreciate you taking the time to post it, though.

 

[KB1OKL]

I remember CKLW and it was a great station, used to pick it up on a RCA 811K console which I still own and still kills any modern AM receiver I've ever heard. I also remember listening to local WORC 1310 which was about a mile from my parents house when I was a kid on this same radio and it sounded great. Good wideband analog AM had a presence that no radio, either AM or FM really has anymore, the DJ's sounded like they were right in your living room.

 

[RememberWHEN]

Yep - wideband analog AM 'presence'. You're correct KB10KL. Problem is, there is almost no way to 'demonstrate' that to anybody that is interested enough to take some time and...give a listen. The receivers (with not only a 'wide audio passband' but a good quality amplifier on the other side of the detector) aren't available. And even if you find one (I have a Denon AMAX tuner at home and a Chrysler/Infinity/Alpine AM stereo car radio) you'll run up against a lot of poorly engineered stations with a host of issues from antenna bandwidth issues back thru misadjusted or ancient processing equipment and, of course, whatever 'source' material is making it's way through the air chain. In this day-and-age, what with the 'wonders' of everything digital (you can read that both ways...digital doesn't guarantee anything...I've heard some pretty grungy stuff along with the,"oh, wow, stuff") a lot of these issues should have disappeared. But they haven't. The AM system is just that. A system. Potential for a weak link in the chain anytime.

Occasionally, I'll 'hear' somebody doing something right on the AM side of the radio equation. My radios 'come to life' and are a joy to listen to. And I'll try to contact the person responsible and thank them. They are always happy to hear that somebody has noticed.

Funny thing, radio. No moving color pictures. Just sound. One of the 'intangibles' you are 'selling' to your prospective advertisers and showcasing to the listeners is your...sound...or, more specifically...your audio signature. Seems that more managements might focus on that. I guess I must be out-of-step. S'cuse me while I grab my meds.

Regards,

RememberWHEN

 

[Tom Wells]

Regarding audio quality on AM analog:

tripinva- I have been posting podcasts of airchecks from m part 15 AM station in Chicago, W-nuthin-nuthin-nothin, 1620.
I have no NRSC cutoff since pt 15 doesn't require this. I transmit full audio, and when I test with material from an FM stereo source,
I can detect the 19 khz pilot in my audio by checking 20 khz up with a bfo, I hear the 1khz whistle.

This is by no means the best audio from an AM, but far better than most people get to hear.
I record to CD from the detector output of a 1980 vintage Sony AM/FM table radio.

This is sample #17.

http://thomasjwells.podOmatic.com/entry/2008-03-08T00_13_57-08_00

 

[KB1OKL]

Regarding audio quality on AM analog:

tripinva- I have been posting podcasts of airchecks from m part 15 AM station in Chicago, W-nuthin-nuthin-nothin, 1620.
I have no NRSC cutoff since pt 15 doesn't require this. I transmit full audio, and when I test with material from an FM stereo source,
I can detect the 19 khz pilot in my audio by checking 20 khz up with a bfo, I hear the 1khz whistle.

This is by no means the best audio from an AM, but far better than most people get to hear.
I record to CD from the detector output of a 1980 vintage Sony AM/FM table radio.

This is sample #17.

http://thomasjwells.podOmatic.com/entry/2008-03-08T00_13_57-08_00

Sounds good, very clear, lacks the bottom of my old console though ;D, I have the 45 of Master Jack around here someplace too. Great stuff! Angel Baby, got that too, one of my all time favorites. Very cool looking studio, love those tubes, got a million of them here.