Time to reconsider AM stereo?

[4dude]

AM STEREO is much better than this digital garbage infecting the airwaves!! (Analogue sounds MUCH BETTER)

 

[KB1OKL]

AM STEREO is much better than this digital garbage infecting the airwaves!! (Analogue sounds MUCH BETTER)

Yes it does, unfortunately many younger people have no idea how really good analog AM can sound.

 

[XavierRenegade]

There doesn't seem point to have AM HD stations. There is no additional content just a digital broadcast of the regular AM station. I can listen to 93.1 Jack FM HD-2 and listen to KFWB News 980. On 94.7 the wave FM HD-2 I can listen to KNX 1070 News Radio. I don't need to be able to listen to KNX or KFWB in HD on the AM dial. It seems pointless. Having HD on FM gives me a chance to listen additional HD stations including some news and even sports.

There is already some talk on FM but I could care less about talk radio. There are some markets that do offer Sports Radio stations on the FM dial but its places like Washington DC, Baltimore, New York and Detroit. In Los Angeles or San Diego they don't have any sports radio stations on FM just AM radio.

 

[Play Freebird]

I wonder if the stations that have been using translators under STA's will be required to adhere to the coverage/distance rules?

The STA's shouldn't have been granted unless an exhibit was submitted showing that those requirements were met.

We acquired three translators for our daytimer last year and they are doing a fine job; we can now serve our market on a fulltime basis and begin the morning show at 6 AM year-round. Previously, in four months out of the year, it wasn't possible to sign on until after 7 AM , even taking advantage of pre-sunrise authority.

I've also worked on similar translator projects for a few of my small-market AM clients and they are all very pleased with the results. The question is: Why did the NAB fight this proposal for so long? AM translators have been legal in Alaska for many years and had been proposed for the remaining states, but NAB's firm opposition kept the FCC from opening this opportunity until recently.

 

[w9wi]

The FCC Order authorizing AM use of FM translators is very restrictive. The 60 dbu contour of the translator can't extend beyond 25 miles from the transmitter site or beyond the AM's 2 mV contour, whichever is less. Plus, only presently licensed translators are eligible. Assuming you can find an existing translator, that's a tough standard to meet. Especially for stations with a directional signal.

It's not uncommon for an AM station to have a deep null over an unpopulated area in order to maximize signal over the population; however, that null comes into play when determining whether you can use a translator since it sucks in the 2mV contour. Also, many AM's are located outside of the population center for real estate reasons, and that brings the 25 mile rule into play.

It should be noted the 60dBu must be within the 2mV daytime contour of the AM station. It may well exceed the 2mV nighttime contour.

AM stations with directional daytime signals are certainly not rare, but they're a lot less common than stations that are only directional at night. (or are directional at all times but have a night pattern that's MUCH tighter than the day pattern) The latter stations, as well as the Class D stations (usually non-directional but with little or no night power) and Class C stations (usually same facilities day and night but with severe nighttime interference problems) will benefit from translators.

 

[Play Freebird]

Note also that the final rule does not specify whether the location of the daytime 2 mV/m contour is to be based on M3 conductivities or measured data (which implies that you can choose the method which works in your favor) In most cases, use of M3 will show a greater distance to the contour. That's what I've usually submitted in the past and the FCC has never raised any questions.

 

[JohnnyElectron]

Yes, iBquity should bite the bullet and reprogram their HD generators to broadcast in "C-QuamII" aka AMHiFi or AMAX. It would be compatible with all the Ford, Delco and Chrysler CQuam receivers out there, but on the HD tuners, it not only would decode the CQuam stereo audio, but also add the data with station ID.
I'm game, and the time is now.

 

[SUPERCASTER]

Yes, iBquity should bite the bullet and reprogram their HD generators to broadcast in "C-QuamII" aka AMHiFi or AMAX. It would be compatible with all the Ford, Delco and Chrysler CQuam receivers out there, but on the HD tuners, it not only would decode the CQuam stereo audio, but also add the data with station ID.
I'm game, and the time is now.

What?
Continue to pay iBiquity's royalties?

Why not just buy a new C-Quam generator?
Link:
http://www.deltaelectronics.com/amprod.htm

 

[wnmb]

As in my earlier post, AM Stereo works. I invite anyone who has not heard it to come visit with us at WNMB in North Myrtle Beach, or get in touch with Matt Smith at WZKY in Albemarle, N. C. Should you not be able to visit and would like to hear it, I will be happy to send you an aircheck recorded from a Sony SRF-A100 receiver. You can e-mail us at [email protected]

 

[audioguy]

Thanks to everyone for the interesting and informative responses to my post. I would love to see AM stereo make a comeback! It would be a vast improvement over IBOC. "What's old is new again"!

Is stereo important for AM radio? Well, perhaps not, if your station is talk only. But it must be recognized that stereo transmission is the de facto standard for all audio channels. Radio tried and abandoned quad and other multi-channel formats, but stereo has survived. Not only on radio, but also on television, home audio systems, portable music players, and the Internet. Most AM stations have at least some musical content that would benefit from stereo transmission, even if it's only during commercials or sounders.

Is AM radio itself still relevant? Well perhaps at some future date it will indeed go away, but there are thousands of licensed facilities on the air, with millions of listeners. Owners have made (and continue to make) significant investments to maintain and upgrade these facilities. I don't think that most of them are going away anytime soon. There is currently no alternative use for the AM radio band, and there are millions and millions of AM radios in circulation.

AM stereo could benefit from the use of digital signal processing technology in receivers. A few years ago Motorola announced a new line of integrated circuits for receivers called the "Symphony" series, that could have greatly improved reception. Probably they would not re-introduce this line, but there is always the possibility that new ones could take its place.

If one or two of the major networks would switch off their IBOC jammers and put AM stereo back on the air and promote it, that would be a major step toward revitalizing the AM band.

 

[Play Freebird]

Thanks to everyone for the interesting and informative responses to my post. I would love to see AM stereo make a comeback! It would be a vast improvement over IBOC. "What's old is new again"!

If one or two of the major networks would switch off their IBOC jammers and put AM stereo back on the air and promote it, that would be a major step toward revitalizing the AM band.

Your ideas are good and I agree that DSP would really help to improve AM Stereo receiver quality. The only thing I would add is an optional, non-proprietary, low speed data subcarrier, similar to RDS but using the spectrum below the pilot tone. It would not need to carry more than the station's callsign or "handle", two lines of text for title and artist info, website/stream URL, and alternate frequencies (to facilitate automatic retuning to translators).

 

[midatlanticengineer]

Yes, iBquity should bite the bullet and reprogram their HD generators to broadcast in "C-QuamII" aka AMHiFi or AMAX. It would be compatible with all the Ford, Delco and Chrysler CQuam receivers out there, but on the HD tuners, it not only would decode the CQuam stereo audio, but also add the data with station ID.
I'm game, and the time is now.

What?
Continue to pay iBiquity's royalties?

Why not just buy a new C-Quam generator?
Link:
http://www.deltaelectronics.com/amprod.htm

Or....upgrade that old tube transmitter with a BE transmitter and be sure to get the stereo cards to go with it.


Google Groups "AM Stereo (AM Broadcast Radio)" group.
http://groups.google.com/group/amstereo

 

[midatlanticengineer]

BTW...does anyone know for certain which HD radios are capable of decoding C-Quam? I know it seems that the good old analog C-Quam receivers are getting harder and harder to find unless you go to special websites or buy an older receiver and vehicle.

I'm doing a bit of probing into this, as should everyone else. There -are- some stations out there that would start operating in C-Quam right now - IF - they knew for certain that the receivers were easy to get/find and readily available at decent prices.

Without the receivers, it's almost pointless.

AM owners/operators also need to provide something of worth to listen to. AM radio doesn't - HAVE - to be talk radio. I know of several music AM stations that do quite a good job at it.




Google Groups "AM Stereo (AM Broadcast Radio)" group.
http://groups.google.com/group/amstereo

 

[radioskeptic]

If you're looking for a C-Quam receiver, you might consider the Meduci AMX-2000, which is only an AM tuner -- but what a tuner! Unfortunately, it costs $150, direct from the manufacture. That's an awful lot for a tuner, but it's an extraordinarily well-designed and well-built AM-only tuner.

You can see the owner's manual here: http://meduci.com/amx2000.pdf

And here's an interesting excerpt from the manual's Q & A section:

Q: I saw your AM Stereo radio on the Internet and it looks like a well designed unit. I am wondering if
you will ever decide to produce an IBOC unit, since all the stations in this area have turned off their
stereo encoders in favor of IBOC. I believe your receiver will be a good RF section for an IBOC receiver.

A: There are at least two chips developed by Texas Instruments (TI) for decoding the iBiquity HD Radio
bit stream. When we contacted Texas Instruments about purchasing engineering samples of their chipsets,
TI said that we first needed to obtain a manufacturing license from iBiquity. When subsequently
contacting iBiquity, we were notified that a $25,000 up-front payment was required to license their
proprietary HD Radio technology; we also would need to make royalty payments to iBiquity for each
tuner sale. Given the negligible profit margin, we would have to sell many, many AMX2000 tuners to be
able to afford the up-front manufacturing license and other costs.

What? $25,000 to license the technology before you can even buy a chipset just to try it out? Before you finalize your design, never mind your marketing plan?

 

[midatlanticengineer]

Yeah I've seen the radio...but for general all around purposes like for automotive use and so forth...its not very practical. If C-Quam is to make a return in the market, receivers have to be out there for the consumer to buy.

Look at IBOC radio ....aside from the analog audio quality, digital audio quality in many cases and the "noise" pollution that some hear on their radios, how many stores can you go into right now and purchase an IBOC radio....portable or automotive?

Broadcasters can transmit all the digital streams and or C-Quam platforms all they want...all day long, but if the general practical receivers are not out there, forget it.

 

[audioguy]

I have read that some of the HD radios can also decode C-QUAM, although I have no personal experience with this. The question is really more about whether AM broadcasters would be willing to get behind AM stereo and promote it. Or, would they rather continue to shell out licensing fees to iBiquity for an "HD" system that doesn't work? Alternatively, is AM radio going to be satisfied staying with monophonic transmission when every other audio device you can buy delivers a stereo listening experience?

I don't think it would be very expensive for most stations to switch to AM stereo. Some of them already have the gear; it's probably just sitting in an equipment closet collecting dust. As far as I know it doesn't cost any more to operate an AM stereo transmitter than a mono transmitter, and the audio can sound very good in mono or stereo (and much better than an HD station received in analog). C-QUAM doesn't create any additional interference. So what is the downside, even if in the near term there were no more stereo listeners than there are currently HD AM listeners?

It's a chicken-and-egg thing: nobody wants to make receivers if there are no stations to listen to, and nobody wants to broadcast if there are no receivers out there. But in this case, it seems that the cost of "priming the pump" on the broadcast side should be quite low in comparison to HD AM. If a number of key stations were to switch to AM stereo and promote it, new receivers would eventually be introduced, because this is fairly simple to do now that more and more of them are becoming, in effect, software defined radios.

I don't think AM radio has a lot of other possibilities left. The bandwidth is too small to support more advanced modulation schemes.

 

[KB1OKL]

BTW...does anyone know for certain which HD radios are capable of decoding C-Quam? I know it seems that the good old analog C-Quam receivers are getting harder and harder to find unless you go to special websites or buy an older receiver and vehicle.

I'm doing a bit of probing into this, as should everyone else. There -are- some stations out there that would start operating in C-Quam right now - IF - they knew for certain that the receivers were easy to get/find and readily available at decent prices.

Without the receivers, it's almost pointless.

AM owners/operators also need to provide something of worth to listen to. AM radio doesn't - HAVE - to be talk radio. I know of several music AM stations that do quite a good job at it.




Google Groups "AM Stereo (AM Broadcast Radio)" group.
http://groups.google.com/group/amstereo

I just went to the website you posted and found that it has turned into an IBOC-DRM discussion group!
If you want an AM stereo website try

http://www.amstereoradio.com/

 

[strangelove]

If i had to choose between the 1996-webstream-quality of IBOC on AM and this: http://www.youtube.com/watch?v=Wm_iYK-ctiQ I think I know which one I'd prefer.

 

[Savage]

Thanks strangelove - a great link and a sobering thing to listen to. When I listen to "what could have been" - as opposed to where we are now, with the AM band a complete interference-choked mess - it absolutely breaks my heart.

I grew up in this business with managers who constantly juggled the "quality-versus-loudness/coverage" issues. A station's technical sound was a point of pride. But not today, thanks for engineering cretins willing to dial back audio quality to the equivalent of bad 78rpm records in order to accomodate IBOC. You can't even make the claim HD forces AM back to 1920s sound. Even crystal sets sounded better than today's HD-strangled AM signals.

Yep: THIS is where we COULD be today. But for a corrupt government and a handful of "expert" jerks and crooks.

And you know who you are, Dan, Glynn, Cris, Tom, Peter, et al.

 

[ddsparxx]

If you're looking for a C-Quam receiver, you might consider the Meduci AMX-2000, which is only an AM tuner -- but what a tuner! Unfortunately, it costs $150, direct from the manufacture. That's an awful lot for a tuner, but it's an extraordinarily well-designed and well-built AM-only tuner.

You can see the owner's manual here: http://meduci.com/amx2000.pdf

And here's an interesting excerpt from the manual's Q & A section:

Q: I saw your AM Stereo radio on the Internet and it looks like a well designed unit. I am wondering if
you will ever decide to produce an IBOC unit, since all the stations in this area have turned off their
stereo encoders in favor of IBOC. I believe your receiver will be a good RF section for an IBOC receiver.

A: There are at least two chips developed by Texas Instruments (TI) for decoding the iBiquity HD Radio
bit stream. When we contacted Texas Instruments about purchasing engineering samples of their chipsets,
TI said that we first needed to obtain a manufacturing license from iBiquity. When subsequently
contacting iBiquity, we were notified that a $25,000 up-front payment was required to license their
proprietary HD Radio technology; we also would need to make royalty payments to iBiquity for each
tuner sale. Given the negligible profit margin, we would have to sell many, many AMX2000 tuners to be
able to afford the up-front manufacturing license and other costs.

What? $25,000 to license the technology before you can even buy a chipset just to try it out? Before you finalize your design, never mind your marketing plan?

I have the AMX2000 tuner; sounds great though I normally don't use it for AM DX.