This will probably cause more trouble but...WABC Rewound 08 airchecks

[Tom Wells]

Lino has posted some NYC AM analog/HD recordings from the KLH tuner, and it does have response up to at least 15 khz.

The tune-in hiss and residual hiss at center tuning was exactly what you would expect to hear from a Hi-fi tuner.
It was audibly high-end restricted at the stations, as you could hear higher decoded AF from the sidebands than the analog modulation.
You mignt like to hear a sample, but you'd likely prefer the artifacting over the hiss and HF audio restriction for longer listening.

I can't remember whether my buddy in high school had AR2s or 3s. They were pretty dull sounding.
Seems they were 16 ohm, the tweeter and mid ranges had wirewound rheostats, and turning them up all the way didn't help much.
Part of the problem was the Alnico magnets of they day were not as strong as those we have today.
I also recall they sopped up power, and didn't turn most of it into audio.

Then too, in the 50's a lot of LPs were out that had not yet benfitted from the RIAA curve, and there were quite a few
competing prior to that, and a lot of them were *really* bright, Columbia's pre-emphasis curve comes to mind.
I bet AR was averaging the sound of the speakers against the average sounding record of the day.

 

[KB1OKL]

Lino when are you going to explain your insulting post to me? Was that a recording of a rebroadcasting of old airchecks from the 60's as I thought recorded from an IBOC radio or what?

From the first post:In glorious hd.

I was listening also on an analog KLH wideband and they sounded way worse. The HD is eons better.....

There you go.


Lino

If it was there I missed it

 

[KB1OKL]

Lino has posted some NYC AM analog/HD recordings from the KLH tuner, and it does have response up to at least 15 khz.

The tune-in hiss and residual hiss at center tuning was exactly what you would expect to hear from a Hi-fi tuner.
It was audibly high-end restricted at the stations, as you could hear higher decoded AF from the sidebands than the analog modulation.
You mignt like to hear a sample, but you'd likely prefer the artifacting over the hiss and HF audio restriction for longer listening.

For anyone to say an IBOC station sounds better on an IBOC receiver than on a wideband receiver is being disingenuous at best. Lino was very vague about what he had there anyway, perhaps on purpose? Yes, If it has a wide front end like any hifi analog AM tuner of course it's going to pick up the hash sidebands and sound terrible, that's not a true comparison. I can hear hifi AM on many of my old tube communications receivers at night with either the 8 or 16 Khz filters. They both kill the sound I heard from Lino's IBOC clips and have better (and more real) high frequency response. Listening to an IBOC AM station on a wideband AM tuner is a ridiculous comparison, it's not the tuner that has the problem it is the IBOC mode of transmission with it's 30 Khz wide saddlebag hash that is picked up on the wideband receiver (with a little carrier in between), we are not all stupid here. I can also tune in an IBOC AM on my receivers with the wide filters on and not only hear the station I can hear the hash at the same time, especially with the 16 Khz filters on. This is not the fault of the radio it is the fault of IBOC.

 

[LinoNYC]

Lino has posted some NYC AM analog/HD recordings from the KLH tuner, and it does have response up to at least 15 khz.

The tune-in hiss and residual hiss at center tuning was exactly what you would expect to hear from a Hi-fi tuner.
It was audibly high-end restricted at the stations, as you could hear higher decoded AF from the sidebands than the analog modulation.
You mignt like to hear a sample, but you'd likely prefer the artifacting over the hiss and HF audio restriction for longer listening.

For anyone to say an IBOC station sounds better on an IBOC receiver than on a wideband receiver is being disingenuous at best. Lino was very vague about what he had there anyway, perhaps on purpose? Yes, If it has a wide front end like any hifi analog AM tuner of course it's going to pick up the hash sidebands and sound terrible, that's not a true comparison. I can hear hifi AM on many of my old tube communications receivers at night with either the 8 or 16 Khz filters. They both kill the sound I heard from Lino's IBOC clips and have better (and more real) high frequency response. Listening to an IBOC AM station on a wideband AM tuner is a ridiculous comparison, it's not the tuner that has the problem it is the IBOC mode of transmission with it's 30 Khz wide saddlebag hash that is picked up on the wideband receiver (with a little carrier in between), we are not all stupid here. I can also tune in an IBOC AM on my receivers with the wide filters on and not only hear the station I can hear the hash at the same time, especially with the 16 Khz filters on. This is not the fault of the radio it is the fault of IBOC.

Lino was very vague about what he had there anyway, perhaps on purpose?

we are not all stupid here

...But you give your best shot.

If this thread were "vague" to you...well..

Lino

 

[Tom Wells]

I'm not being disingenous, I think everyone knows I'd rather hear wideband analog AM.
But if Lino had recorded the WABC-rewound special with the muffled (at source) analog, I don't think I would have bothered to listen.
And I listened to all of the clips, as rebroadcast on AM 1620 at home.

The previously posted AM analog clips did not sound as good as these HD recordings, but I agree this is the fault of the
audio being brickwalled at 5 kc and the hiss, not a fault of the KLH tuner.

Lino's recordings of the analog were very good. I am not saying the signal or audio was good.
I am defending the quality of the recording he made. If 20 khz signal audio had been present, I think we'd have heard it in his recording.
There was hiss at 20 khz, heard during tune-in of signals, and we could hear every little adjustment into center-tuning, when the hiss
was minimized , but not gone, exactly as I have heard with my own radios.

And of course neither can compare to a proper wideband AM analog-only signal as heard on a wideband receiver.

 

[LinoNYC]

I'm not being disingenous, I think everyone knows I'd rather hear wideband analog AM.
But if Lino had recorded the WABC-rewound special with the muffled (at source) analog, I don't think I would have bothered to listen.
And I listened to all of the clips, as rebroadcast on AM 1620 at home.

The previously posted AM analog clips did not sound as good as these HD recordings, but I agree this is the fault of the
audio being brickwalled at 5 kc and the hiss, not a fault of the KLH tuner.

Lino's recordings of the analog were very good. I am not saying the signal or audio was good.
I am defending the quality of the recording he made. If 20 khz signal audio had been present, I think we'd have heard it in his recording.
There was hiss at 20 khz, heard during tune-in of signals, and we could hear every little adjustment into center-tuning, when the hiss
was minimized , but not gone, exactly as I have heard with my own radios.

And of course neither can compare to a proper wideband AM analog-only signal as heard on a wideband receiver.

The analog of current program on WABC (excepting content) would not have sounded that bad, however when combined with the nature of these old airchecks, the fact that they have gone through the original airchain, recording then restoration which often has included for some reason more dynamic compression then stored digitally, the result of putting that through the present analog airchain yields a wall of noise.

Here is a recording from WABC's analog as of 7-15-07 live-local approx 2 months after iboc commenced. You have probably heard this one before, but it does show an analog wider then most average radio I have heard can receive.

http://www.sendspace.com/file/nvfhd6 8mb

Lino

 

[KB1OKL]

...I listen to CHWO 740 Toronto quite often on it.

CHWO is awesome... Isn't it a former CBC facility with a really-tall HALF WAVE stick? Their audio sounds great. 1050 CHUM [maybe in the same building] is less-so. CHUM plays music, and they don't sound all that hot - it's like the IBOC filter without the Harris DeathStar in the rack. What goes with them?

I see the sale went through:http://www.oakvillebeaver.com/news/business/article/177142

Note: "What happens now is up to Moses (new owner), but I'm not aware of any specific changes,

You're thinking Yiddish music?

As usual there will be staff cuts, gotta help the new landlord pay back the money he borrowed from other people.

Canada is getting too capitalist.

Lino

Supposedly there are going to be no changes.

 

[KB1OKL]

I'm not being disingenous, I think everyone knows I'd rather hear wideband analog AM.
But if Lino had recorded the WABC-rewound special with the muffled (at source) analog, I don't think I would have bothered to listen.
And I listened to all of the clips, as rebroadcast on AM 1620 at home.

The previously posted AM analog clips did not sound as good as these HD recordings, but I agree this is the fault of the
audio being brickwalled at 5 kc and the hiss, not a fault of the KLH tuner.

Lino's recordings of the analog were very good. I am not saying the signal or audio was good.
I am defending the quality of the recording he made. If 20 khz signal audio had been present, I think we'd have heard it in his recording.
There was hiss at 20 khz, heard during tune-in of signals, and we could hear every little adjustment into center-tuning, when the hiss
was minimized , but not gone, exactly as I have heard with my own radios.

And of course neither can compare to a proper wideband AM analog-only signal as heard on a wideband receiver.

I wasn't talking about you Tom, Lino said he also heard the same stuff on a KLH tuner and I would have liked to have heard it too alongside the IBOC versions. If he also posted the KLH versions I did not find them, I listen to 25 minutes of hour one (I think) and had enough of the artificial highs. Where are the previously posted analog recordings you said Lino made? When I said ingenious I meant comparing an IBOC station recorded from an IBOC tuner to the same station being recorded on a wideband tuner, of course the wideband tuner is going to pick up the IBOC hash and sound lousy, saying the IBOC tuner sounded better is obvious and ingenious to me, it's like comparing apples and oranges.
I will try to ignore the insults Lino and stay in this thread, I know we all don't have the same towering intellect that you obviously have.

 

[SUPERCASTER]

Lino when are you going to explain your insulting post to me? Was that a recording of a rebroadcasting of old airchecks from the 60's as I thought recorded from an IBOC radio or what?

From the first post:In glorious hd.

I was listening also on an analog KLH wideband and they sounded way worse. The HD is eons better.....

There you go.


Lino

Yup. Your recordings prove beyond a shadow of a doubt how destructive HD radio wrecks havoc with a station's analog signal and, by necessity, adds hiss and cuts AM analog fidelity in half.

Thanks for posting those audio files Lino, that's just what most here have been saying all along. Glad you've joined us. Now, even a rabid HD supporter like yourself has provided what you call "proof" analog and HD radio recordings that you made yourself, totaly under your control.

Yes, a station's AM analog signal sounds absolutely dreadful when the bandwidth is halved and digital hiss is added from HD radio. You proved it yourself, and posted links to the analog and HD radio audio files right here!

As KB10KL said:

For anyone to say an IBOC station sounds better on an IBOC receiver than on a wideband receiver is being disingenuous at best. Lino was very vague about what he had there anyway, perhaps on purpose? Yes, If it has a wide front end like any hifi analog AM tuner of course it's going to pick up the hash sidebands and sound terrible, that's not a true comparison. I can hear hifi AM on many of my old tube communications receivers at night with either the 8 or 16 Khz filters. They both kill the sound I heard from Lino's IBOC clips and have better (and more real) high frequency response. Listening to an IBOC AM station on a wideband AM tuner is a ridiculous comparison, it's not the tuner that has the problem it is the IBOC mode of transmission with it's 30 Khz wide saddlebag hash that is picked up on the wideband receiver (with a little carrier in between), we are not all stupid here. I can also tune in an IBOC AM on my receivers with the wide filters on and not only hear the station I can hear the hash at the same time, especially with the 16 Khz filters on. This is not the fault of the radio it is the fault of IBOC.

 

[KB1OKL]

Lino when are you going to explain your insulting post to me? Was that a recording of a rebroadcasting of old airchecks from the 60's as I thought recorded from an IBOC radio or what?

From the first post:In glorious hd.

I was listening also on an analog KLH wideband and they sounded way worse. The HD is eons better.....

There you go.


Lino

Yup. Your recordings prove beyond a shadow of a doubt how destructive HD radio wrecks havoc with a station's analog signal and, by necessity, adds hiss and cuts AM analog fidelity in half.

Thanks for posting those audio files Lino, that's just what most here have been saying all along. Glad you've joined us. Now, even a rabid HD supporter like yourself has provided what you call "proof" analog and HD radio recordings that you made yourself, totaly under your control.

Yes, a station's AM analog signal sounds absolutely dreadful when the bandwidth is halved and digital hiss is added from HD radio. You proved it yourself, and posted links to the analog and HD radio audio files right here!

As KB10KL said:

For anyone to say an IBOC station sounds better on an IBOC receiver than on a wideband receiver is being disingenuous at best. Lino was very vague about what he had there anyway, perhaps on purpose? Yes, If it has a wide front end like any hifi analog AM tuner of course it's going to pick up the hash sidebands and sound terrible, that's not a true comparison. I can hear hifi AM on many of my old tube communications receivers at night with either the 8 or 16 Khz filters. They both kill the sound I heard from Lino's IBOC clips and have better (and more real) high frequency response. Listening to an IBOC AM station on a wideband AM tuner is a ridiculous comparison, it's not the tuner that has the problem it is the IBOC mode of transmission with it's 30 Khz wide saddlebag hash that is picked up on the wideband receiver (with a little carrier in between), we are not all stupid here. I can also tune in an IBOC AM on my receivers with the wide filters on and not only hear the station I can hear the hash at the same time, especially with the 16 Khz filters on. This is not the fault of the radio it is the fault of IBOC.

Thank you, I'm glad someone took the time to read my whole post and see what I was trying to get at.

 

[KB1OKL]

I've listened to about 25 minutes so far of the first hour, it sounds very clear but I have heard better AM before, the highs sound artificial and I hear no bottom, I could not listen to sound like this for any length of time. If this is what AM IBOC sounds like I'm certainly not going to rush out to buy one. My radios with wide filters sound much better than this and are not tiring to the ears. The longer I listen the more tiring it becomes. I am running this through the system I mentioned above so my stuff is definitely not the limiting factor. Great Aretha Franklin tune though.

I knew it I just knew!!!!

I was talking to a friend in Bangkok not an hour before you posted the brilliant remarks and said to him " some genius on that particular board is gonna hear these 40 year old amateur recordings and blame it on AM iboc".

I've got news for you Sherlock, I was listening also on an analog KLH wideband and they sounded way worse. The HD is eons better not only in frequency response but in that these recording aren't being re-smashed by an airchain designed for talk not music.

If you want an idea of how much better the resolution is, notice the hum on the hour 1 rec during the Chuck Leonard seg, this 'check was intact and original, at the 34 minute point you can hear hum behind Leonard voice leaking from a cart machine that hasn't closed after the Cosell promo. You'll also hear surface noise and some gating action on the quiet intro of the O.C. Smith record.

I listened to this station back then with a Fisher 800 which had a separate AM section w/three bandwidth settings into AR-3 speakers, only with this high quality equipment could you hear these "defects' , on standard AM sets -not.

Lino

Incidentally I think that the recordings sound great for 1963 whoever did it must have had a nice tube reel to reel, it is the exaggerated IBOC highs that ruin it, these clips are great though.

 

[LinoNYC]

Incidentally I think that the recordings sound great for 1963 whoever did it must have had a nice tube reel to reel, it is the exaggerated IBOC highs that ruin it, these clips are great though.

More likely, it's an ineptly set up system at your end, try rolling-off those "exaggerated IBOC highs" you know, with tone controls. Make it nice and muddy.

lino

 

[amfmsw]

Here's my ear-level view.

Lino's HD recordings sounded better than the analog broadcast. The HD suffered greatly from digital artifacts, but had wide f response. The analog broadcast itself suffered from atmospheric noise, hiss, reduced bandwidth. (The full analog AM stations sound remarkably cleaner and brighter than the AM HD simulcast analog on Marantz 2270, 2230 and Fisher 90-R)

I compared them with my recordings. Source: web site stream of the Rewind. Windows Media Player eq set flat. Headphone out from the computer, fed to a pretty average, early 80's, Sanyo-built, Fisher Cassette deck recorded on hi-bias tape with Dolby b. Very little artifacts at all, full f response, clean with much less processing.

In my opinion, the stream was the way to go.

 

[Play Freebird]

Here's something I'm still trying to understand.

If the primary objective of the AM IBOC system is to extend audio frequency response, why can't this be accomplished at the receiver end by retaining the NRSC-1 analog signal (with C-QUAM, if desired) and using DSP-based dynamic IF filters, noise blanking, etc. in the receiver chip? This would be much less complicated than dealing with an in-band digital signal, and would relieve the broadcaster of substantial expenses, not to mention eliminate the adjacent-channel digital interference problem.

If you happen to drive I-80 through the Bloomsburg, PA area, tune to 104.3 and check it out WHLM's FM translator, which is fed by the same processor as the co-located AM. It uses NRSC 75 uS pre-emphasis and 10 kHz low-pass filtering and really doesn't sound bad. On a portable receiver, you'll have a hard time detecting a difference in quality between it and a normal FM station.

Basically, this FM translator (with its 10 kHz filter) simulates the quality all AM stations could achieve with NRSC-compliant analog receivers in the hands of city-grade contour listeners.

 

[RememberWHEN]

Play Freebird quizzes...

If the primary objective of the AM IBOC system is to extend audio frequency response, why can't this be accomplished at the receiver end by retaining the NRSC-1 analog signal (with C-QUAM, if desired) and using DSP-based dynamic IF filters, noise blanking, etc. in the receiver chip? This would be much less complicated than dealing with an in-band digital signal, and would relieve the broadcaster of substantial expenses, not to mention eliminate the adjacent-channel digital interference problem.

You've got something there. But what, oh what, would all the "hedge your bets here" IBUG investors do with that solution. It would trash their (potential) financial future.

Back to your ponder...I don't have any listening experience with DSP filtering and noise blanking of AM signals. I recently obtained a amateur license and at some point will purchase a HF transceiver that will have the above filtering/blanking. Designers tell me that DSP is very powerful and can accomplish some remarkable things. But we're back to the receiver manufactures and the margins the are working on. They have 'dumbed down' the AM side of receivers over the last 30+ years. What would 'force' them to turn the tide and go the other direction? Long ago (and of course this is 'Monday morning quarterbacking it) the AM only broadcasters and the so-inclined AM/FM owners that wanted their AMs to remain competitive should have lobbied the FCC to require manufactures to produce radios that provided reasonable parity in the response characteristics for both bands. RBruceCarter, Hippo, and Savage, what say ye??

Before all the nay-sayers jump here with and state that AM never has and never could compete with FM in terms of sonic signatures...let me just state this. Each of the modulation systems has its limitations. The textbook amplitude modulation scheme has no inherit frequency limitations. Real world limitations on the transmission side (apart from any issues studio through transmitter input - which should not be an issue in this day) is the passband of the antenna system. (Interesting sidebar: IBUG has very stringent requirements on that passband - much more so than C-QuAM - and it frankly won't work if it isn't correct). Again, that's on the transmission side of the equation. Where the system is broken is on the reception side. Anyone who has heard an AM system where everything is correct on the transmission side and a good quality wideband receiver is available will attest to the 'open' and very 'listenable' quality that AM exhibits. The 'high frequency' busyness and artifacts that historically has been a challenge for the FM system because of the pre-emphasis just isn't there! In some cases (and yes, rare, because everything has to be correct) on an A-B comparison of the same programming thru both systems you might vote for the AM signal!!

 

[KB1OKL]

Incidentally I think that the recordings sound great for 1963 whoever did it must have had a nice tube reel to reel, it is the exaggerated IBOC highs that ruin it, these clips are great though.

More likely, it's an ineptly set up system at your end, try rolling-off those "exaggerated IBOC highs" you know, with tone controls. Make it nice and muddy.

lino

I left it the way I always listen to everything with both bass and treble all the way up. It didn't sound muddy at all, just kind of artificial, I'm a bass player who has been recording for 40 years, although I've never been in any name bands close several times but no cigar like many musicians but I do know how to evaluate sound. For many people that IBOC sound may be an improvement over regular dull AM (frequency limitations inposed by the FCC of course) by I can't get by about 25 minutes, sounds very saccharine to me after a while and tires my ears out. One of the best sounding recording I have ever heard is an LP of "The Bridge" by Sonny Rollins, this is a new RCA recording I bought within the past 5 years and don't know if it was remastered digitally or not, I suspect not as many jazz aficionados are purists.

 

[LinoNYC]

Here's something I'm still trying to understand.

If the primary objective of the AM IBOC system is to extend audio frequency response, why can't this be accomplished at the receiver end by retaining the NRSC-1 analog signal (with C-QUAM, if desired) and using DSP-based dynamic IF filters, noise blanking, etc. in the receiver chip? This would be much less complicated than dealing with an in-band digital signal, and would relieve the broadcaster of substantial expenses, not to mention eliminate the adjacent-channel digital interference problem.

There exists such a package system: Motorola Symphony. It would still be my preference, however there are some realities to consider:

1) AM only solutions have not worked in solving the demo problem. Owners spent heavily to rebuild entire airchains for AMs and got no improvement in audience demographics in return. One, slightly humiliating reason that AM iboc has appeal is that it can piggyback on the FM system.

2) While the whole world of communications and entertainment is "going digital" iboc gives a viable way of including radio.

3) Out-of-band failed. The Europeans and Canadians are quietly phasing out some (eventually all) of their 13 year experiment w/Eureka. They have found that conversion of aural transmission is going to be too longterm to expect broadcasters to sustain a separate service. The UK seems to be the only (moderate) success.

All of Asia and most of Europe are now exploring in-band tech.

Maybe that our system won't turn out to be best, but this is the direction the world is going.

Mostly historical interest: http://radiomagonline.com/departments/radio_motorola_symphony_digital/

Lino

 

[Play Freebird]

There exists such a package system: Motorola Symphony. It would still be my preference, however there are some realities to consider:

1) AM only solutions have not worked in solving the demo problem. Owners spent heavily to rebuild entire airchains for AMs and got no improvement in audience demographics in return. One, slightly humiliating reason that AM iboc has appeal is that it can piggyback on the FM system.

So why couldn't a "Symphony" type AM demod be paired with FM IBOC in the same chip? I'm just after the end result (better audio quality) and experience has shown that in-band AM IBOC creates more problems than it solves. But I guess this isn't a technical problem, it's a "how to save face" problem.

2) While the whole world of communications and entertainment is "going digital" iboc gives a viable way of including radio.

3) Out-of-band failed. The Europeans and Canadians are quietly phasing out some (eventually all) of their 13 year experiment w/Eureka. They have found that conversion of aural transmission is going to be too longterm to expect broadcasters to sustain a separate service. The UK seems to be the only (moderate) success.

Could it be the Europeans are mostly satisfied with FM as it stands and see no need for digital? Germany's FM system works quite well, thanks to RDS alternate frequency switching and attention to detail in the audio chain. I've listened to classical music broadcasts on some of the German "Öffentlich-Rechtlich" (public) radio networks that were amazingly clean.

The major complaint I've heard about Eureka is that the MPEG-2 codec doesn't sound good at the bitrates used. But America isn't far behind in the race to the bottom; iBiquity's latest software will allow our HD-1 bitrate to be reduced to 32k!

From a purely technical standpoint, Japan may have taken the most sensible approach in adopting ISDB, which supports both TV and radio using the same "pipe". Here is one of Wikipedia's better articles describing the system:

http://en.wikipedia.org/wiki/Integrated_Services_Digital_Broadcasting

 

[Chuck]

There exists such a package system: Motorola Symphony. It would still be my preference, however there are some realities to consider:

1) AM only solutions have not worked in solving the demo problem. Owners spent heavily to rebuild entire airchains for AMs and got no improvement in audience demographics in return. One, slightly humiliating reason that AM iboc has appeal is that it can piggyback on the FM system.

I agree that Symphony would be a far better solution. I have no idea why it has never really been given a chance to demonstrate its benefits.

As for the demo issue, sound quality isn't going to single-handedly fix this. It is a part of the problem, but not the total cure. Once you get the thing to sound decent (and that could be done) you need to provide some programming that appeals to the demo you are trying to attract. If you clean up your signal to hi-fi standards, but put on programming like Rush or Colon Blow infomercials, you will not get many listeners in that important 18-35 demo. It simply is not going to happen.

 

[LinoNYC]

I doubt that it's a matter of "save face" -more licensing and complex dsp architecture. Both systems have to be licensed and with AM increasingly becoming an afterthought, how likely is it that any manufacturer would bother.

If AM is to be in the game, it'll have to piggyback w/FM tech.

The major complaint I've heard about Eureka is that the MPEG-2 codec doesn't sound good at the bitrates used. But America isn't far behind in the race to the bottom; iBiquity's latest software will allow our HD-1 bitrate to be reduced to 32k!

Eureka's codec is obsolete, early 1990's compression, the receivers cannot be live updated and there exists no minimal standard for bitrate. Greed and in this case desperation being what they are stations will try to cram whatever they can onto a carrier (pod). The failure of Eureka is a confluence of circumstances, but mostly it's just a case of technology moving much faster now than when it was designed.

Lino