Back to analog stereo AM?

[HadYourPhil]

The early-2000's Chrysler radios had teriffic AM stereo. And, speaking as one who has built AM stereo stations, you can asymmetrically modulate them. Maybe not to 150%...
I wish that AM stereo had caught on more. It could sound really fine.

 

[Savage]

Amen to that, Phil. WWKB in Buffalo sounded like an FM when it was C-QUAM. Actually, better, at least to my tastes - less gritty and screechy. There are numerous examples of fine AM stereo signal airchecks available on youtube and other sites.

The manual for my BE AM 2.5, which came with C-QUAM as standard equipment (which I am sorry to say we don't use) recommends not exceeding 110% positive in stereo mode. Maybe other transmitters were more tolerant of asymmetry.

 

[HadYourPhil]

I was ustng an AM-1 and AM-10A, and yes they did say 110% was about it. I pushed it a little harder though, but thought it sounded fine.

 

[KB1OKL]

The early-2000's Chrysler radios had teriffic AM stereo. And, speaking as one who has built AM stereo stations, you can asymmetrically modulate them. Maybe not to 150%...
I wish that AM stereo had caught on more. It could sound really fine.

I had an 88 Plymouth Horizon that had an AM stereo radio in it. At night I used to drive up to Burlington VT from here in MA and listen to stereo stations all the way up, I thought it sounded great too.

 

[N1WVQ]

Amen to that, Phil. WWKB in Buffalo sounded like an FM when it was C-QUAM. Actually, better, at least to my tastes - less gritty and screechy. There are numerous examples of fine AM stereo signal airchecks available on youtube and other sites.

The manual for my BE AM 2.5, which came with C-QUAM as standard equipment (which I am sorry to say we don't use) recommends not exceeding 110% positive in stereo mode. Maybe other transmitters were more tolerant of asymmetry.

Just out of curiosity (OK, I loooove A.M. Stereo & and on a few e-mail lists), what is needed for WYSL to go stereo? Is the card in your XMTR.? Is it the audio processor is still mono? Thanks!

 

[tomservo]

I'm curious about why more stations don't use the AM stereo equipment if they already have it. I've been told elsewhere that older stuff is very fiddly and requires a watchful engineer to keep it working. Can't be any worse than keeping HD on.

 

[Savage]

C-QUAM's built into the BE exciter. All you've gotta do is swing open the front panel door, push the button and step it from MONO-LEFT to STEREO. Change the processing over to stereo and run 8723 to the transmitter instead of 8451, for the extra audio pair.

The big 25kw Nautel box for daytime is stereo-ready too.

I would need to buy a stereo modulation monitor though. And the FCC requires regular audio proofs (ironic in this day of IBOC, eh? )

The hitch is, we don't play music....... ???

 

[badjef]

If C-QUAM had become the norm a la FM Stereo, AM might have entered a new era of quality audio. But it was not to be.

We have the brilliant minds at the FCC to thank for that...

Actually, we have Leonard Kahn's legal manipulations to thank for that.

With all due respect, David, we have the FCC and Motorola for the fact we didn't have ISB as the standard long before.

Jeff in Sa-ra-so-ta!

 

[R.F. Burns]

As much as some in here want AM Stereo to come back and save AM radio, you might as well wish for the return of 1976 as well or the return of the old RCA needle in groove video disc. It isn't going to happen. AM radio is on life support and the longterm outlook isn't very good, unless you're one of the 50 KW 1A's.

 

[davideduardo]

With all due respect, David, we have the FCC and Motorola for the fact we didn't have ISB as the standard long before.

In the late 70's, we were ready for the FCC to pick the system for AM stereo out of a field of 5. Leonard Kahn sued, and the FCC did not act, in a manner of speaking, until the early 80's... about 5 years. During that period, AM listening went from about half of all listening to about 40%, with FM having a 20% lead on the "old band." Those 5 years killed any chance of AM stereo being of interest to consumers and, thus, converted AM into a talk band destined to age with its listeners.

 

[N1WVQ]

If C-QUAM had become the norm a la FM Stereo, AM might have entered a new era of quality audio. But it was not to be.

We have the brilliant minds at the FCC to thank for that...

Actually, we have Leonard Kahn's legal manipulations to thank for that.

With all due respect, David, we have the FCC and Motorola for the fact we didn't have ISB as the standard long before.

Jeff in Sa-ra-so-ta!

Good thing we never had ISB as the standard. First off, never mind platform motion: if the station I used to work @ on 1570 had been in ISB stereo, the left channel would've gotten killed every night from 1560-New York. Secondly, from what I heard, ISB didn't have the best sound. Maybe up to 6kc.. Thirdly, the F.C.C. originally chose (what to my ears was the best system) Magnavox when Kahn sued. Essentially, for the 1st time, I am agreeing with David: Kahn's lawsuit doomed any system to be chosen. But then again, from someone whose website is called "Wrath of Kahn" I don't expect a gracious loser.

 

[badjef]

With all due respect, David, we have the FCC and Motorola for the fact we didn't have ISB as the standard long before.

In the late 70's, we were ready for the FCC to pick the system for AM stereo out of a field of 5. Leonard Kahn sued, and the FCC did not act, in a manner of speaking, until the early 80's... about 5 years. During that period, AM listening went from about half of all listening to about 40%, with FM having a 20% lead on the "old band." Those 5 years killed any chance of AM stereo being of interest to consumers and, thus, converted AM into a talk band destined to age with its listeners.

You are not going back far enough. Why not 1961? When FM was authorized use of stereo. TV and AM could have had it, then. By the time the late '70's, it was too late. The momentum for FM was not reversible.

The 10 years of the 80's did not see a fair "marketplace" dicision, it saw just the opposite. A company that designed an AM stereo system to eliminate AM stereo from the marketplace and eventually take the AM band with it in the process. Motorola wanted the band for some type of cellular phone technology which was in it's infancy at the time.

Watching the politics of AM stereo was sickening and disgusting.

The marketplace lost as a result, so did we all.

Jeff in Sa-ra-so-ta!

 

[N1WVQ]

C-QUAM's built into the BE exciter. All you've gotta do is swing open the front panel door, push the button and step it from MONO-LEFT to STEREO. Change the processing over to stereo and run 8723 to the transmitter instead of 8451, for the extra audio pair.

The big 25kw Nautel box for daytime is stereo-ready too.

I would need to buy a stereo modulation monitor though. And the FCC requires regular audio proofs (ironic in this day of IBOC, eh? )

The hitch is, we don't play music....... ???

Would you mind if I asked the A.M. Stereo e-mail lists if anybody happens to have an A.M. stereo mod. monitor? There may be some lonely box sitting somewhere, unloved, collecting dust.

Back in the '90s there were some talk & news stations in C-QuAM. I remember hearing WBZ in stereo then. Wow did they ever sound good! There is an added presence there. Also, I remember the lists talking about some talk stations which deliberately left the stereo on so they'd sound brighter.

You have to proof 10.2kc. of audio but not splattering out 30!

 

[satech]

Would you mind if I asked the A.M. Stereo e-mail lists if anybody happens to have an A.M. stereo mod. monitor? There may be some lonely box sitting somewhere, unloved, collecting dust.

A lot of AM IBOC stations are using C-Quam modulation monitors, because it allows them to measure their incidental phase modulation (IPM). Minimizing IPM and optimizing the antenna bandwidth are the two key goals in getting the best performance from both IBOC and C-Quam.

 

[radioman148]

Zach, you should have tuned in for the Dick Biondi 50th. Totally awesome, that was!

Indeed Dick Biondi's 50th was GREAT radio!

 

[badjef]

If C-QUAM had become the norm a la FM Stereo, AM might have entered a new era of quality audio. But it was not to be.

We have the brilliant minds at the FCC to thank for that...

Actually, we have Leonard Kahn's legal manipulations to thank for that.

With all due respect, David, we have the FCC and Motorola for the fact we didn't have ISB as the
standard long before.

Jeff in Sa-ra-so-ta!

Good thing we never had ISB as the standard. First off, never mind platform motion: if the station I used to work @ on 1570 had been in ISB stereo, the left channel would've gotten killed every night from 1560-New York. Secondly, from what I heard, ISB didn't have the best sound. Maybe up to 6kc.. Thirdly, the F.C.C. originally chose (what to my ears was the best system) Magnavox when

Kahn sued. Essentially, for the 1st time, I am agreeing with David: Kahn's lawsuit doomed any system to be chosen. But then again, from someone whose website is called "Wrath of Kahn" I don't expect a gracious loser.

Cool name for a website dealing with the AM stereo abortion.

Why is Kahn the bad boy in all of this? He had a system that worked 20 years before anybody else did! You guys are blaming the hockey player who turns around and defends himself from being clubbed in the back by the other team's player.

C-quam was not reliable. I have mentioned it before, the ISB range was equivilent to mono. And it did not revert to mono at the tap of a horn - C-quam did.

Jeff in Sa-ra-so-ta!

 

[davideduardo]

You are not going back far enough. Why not 1961? When FM was authorized use of stereo. TV and AM could have had it, then. By the time the late '70's, it was too late. The momentum for FM was not reversible.

The 10 years of the 80's did not see a fair "marketplace" dicision, it saw just the opposite. A company that designed an AM stereo system to eliminate AM stereo from the marketplace and eventually take the AM band with it in the process. Motorola wanted the band for some type of cellular phone technology which was in it's infancy at the time.

It took 3 years to get the first 100 FM stereo stations on the air... a fact well documented in Broadcasting Magazine.

Except for the initial platform motion of CQuam in vehicles, there was nothing wrong with that system... but that is irrelevant in that no system was picked in the late 70's because the matter went into litigation. And the litigation lasted just long enough to remove AM from play as a music medium.

 

[davideduardo]

Why is Kahn the bad boy in all of this?

Because he held up AM stereo for just long enough for AM to die as a music medium.

He had a system that worked 20 years before anybody else did!

Ing. González in Mexico developed a working color TV system years ahead of the RCA system. The problem was it did not work as well. Just because the system was developed first does not make it better.

You guys are blaming the hockey player who turns around and defends himself from being clubbed in the back by the other team's player.

No, I am blaming the guy who took all the sticks and said "puck you" if you don't play the way I want to play.

 

[badjef]

Why is Kahn the bad boy in all of this?

Because he held up AM stereo for just long enough for AM to die as a music medium.

He did not hold it up, he had a working system, field tested and ready to go.

He had a system that worked 20 years before anybody else did!

Ing. González in Mexico developed a working color TV system years ahead of the RCA system. The problem was it did not work as well. Just because the system was developed first does not make it better.

It DID work and better than the other systems. With the range of mono.

You guys are blaming the hockey player who turns around and defends himself from being clubbed in the back by the other team's player.

.
No, I am blaming the guy who took all the sticks and said "puck you" if you don't play the way I want to play.

Whether he was difficult to deal with is quite another issue. But he had the system the market should have had access to.

Is it possible it was during congressional hearing on the adoptation of multicasting? Trying to explain the intricacies of broadcasting to pea-brained elected members can be frustrating at best, I'm sure.

Jeff in Sa-ra-so-ta!

 

[satech]

He did not hold it up, he had a working system, field tested and ready to go.

Leonard Kahn's biggest problem was Leonard Kahn. He had a golden opportunity when the FCC failed to select a single system as the AM Stereo standard (which would've been Harris, the second time around), but he wasted it by putting his ego above all else. Most Kahn AM Stereo installations were done by Leonard himself, because he didn't trust anyone else to do it. Instead of licensing his decoder chip to receiver manufacturers, he built his own radios, using modified Radio Shack tuners. And instead of hiring a marketing department, he hired lawyers to tie Motorola up in court with allegations of patent violations well into the '90s.

Any of the proposed AM Stereo systems (even Belar, which dropped out early) would've been a viable technical solution. All had their shortcomings, which could've been improved on over the years, just as Motorola did with their later decoder chips which solved the "platform motion" problem by smoothly blending to mono in poor signal conditions.

And all of this just underscores how AM IBOC, even with only one system to deal with, is not a viable solution, and even with a huge marketing effort and fair amount of receivers on the marketplace, is a failure which even of its most diehard supporters are slowly abandoning.