WJR's Creative Director John Marshall reflects back on Ed's life. You can listen now by clicking here! 
|
Today's Date... |
NEWS BULLETINS
FOR IMMEDIATE RELEASE
Welcome to the world of AMAX™ AM high fidelity and meduci AM stereo wideband sound, day and night. The future of radio is now. AMAX is here. AMAX is "AM Radio at its MAXimum Potential" in the 21st century. Better reception. Better sound. Please visit Wikipedia and AMAX for further details.
We have adopted Motorola's C-QuAM™ technology, and are proud to offer their latest integrated circuit decoder technology available for C-QUAM™ stereo tuners, to provide optimum and accurate AM stereo performance. We re-launched AM Stereo and gave C-QuAM™ a second chance in the marketplace by introducing new products.
These AM stereo products cannot economically be purchased anywhere else. There are many AM medium-wave stations broadcasting wideband full fidelity sound. When received using an appropriate wide band AM stereo receiver or tuner, the recovered noise-free high definition sound is virtually indistinguishable from FM stereo broadcasts. Hearing is believing! Sample one of our AMAX high definition products, and judge the enhanced fidelity for yourself.
| History of AM Stereo |
Analog AM stereo technology has claimed its roots almost since the beginning of conventional monaural AM broadcasting within the United States. Later, four different competing AM stereo systems were placed on the air in the early 1980's, including systems from Motorola (C-QuAM™), Magnavox (PMX), Kahn-Hazeltine (ISB), and Harris Broadcast (Variable Angle Compatible Phase Multiplex, or V-CPM). Eventually in 1993, Motorola's C-QuAM technology achieved the exclusive standard for AM stereo broadcasting within the U.S.A. During this time period, Australia, Japan, and other countries were also exclusively using the Motorola C-QuAM system, making C-QuAM the essential de facto world standard for AM stereo broadcasting technology.
All of the AM stereo systems share in common the addition of a stereo exciter to the existing monaural AM transmitter. This exciter typically has two outputs: the monaural L+R audio, which is time delayed and fed to the transmitter's normal audio input; the second output is the R.F carrier, which replaces the signal from the transmitter's normal quartz crystal oscillator stage. This signal also contains the necessary time delayed and phase modulated (quadrature) information. Because these stereo exciters are retrofitted onto transmitters which were never designed for AM stereo operation, they also must contain corrective equalizers and adjustable delay networks, to insure that all of the relationships are correct through the transmitter modulator, power amplifier, and ATU/antenna system. Decoded stereo separation suffers if the timing and phase relationships are not correct at the receiver.
Motorola's C-QuAM system is covered in several U.S. patents written by Frank H. Hilbert and the late Norman W. Parker of Illinois. Norman Parker invented the C-QuAM system, per written correspondence from his wife, Margaret Parker. Margaret also wrote all of the patents. Patent number 4,218,586 was applicable to the basic system. Other patents included 4,406,922 and 4,192,968. Delco Electronics Corporation (now known as Delphi) later introduced many adaptations and new C-QuAM inventions, covered under various additional U.S patents.
| About iBiquity HD Radio |
There is a new technology called HD Radio from iBiquity. The letters HD do NOT stand for High Definition audio. Some would say that the two letters stand for Hybrid Digital. This is a hybrid digital / analog mode, until there are sufficient HD radios available in the marketplace, to allow stations to discontinue analog broadcasting (which may take two human lifetimes). In the hybrid mode, this HD invention allows FM stations to add value to their program content and to stream additional programming (HD1, HD2, and HD3) to consumers with HD radios (up to eight streams in the full digital mode). This provides potential new revenue opportunities, as well as a better footing to compete against satellite radio, MP3 players, compact disks, and other consumer technologies. Program information is also available in text format on the HD Radios, to display song title, traffic alerts, music format, or other specific content. There are still shortcomings with this FM HD technology, primarily lack of in-building penetration. Even still, HD Radio has legs for the FM broadcast medium. This cannot be said for the AM broadcast band.
AM stations use iBiquity's digital techniques to transmit a low bit-rate signal to specialized HD radios designed to receive this narrow-band signal. Each AM station is allowed to transmit one stereo digital channel, and cannot stream multiple channels, as in the case of FM HD Radio.
Currently, there are inherent flaws that make it extremely difficult to reliably and continuously receive a 50kW AM station's HD signal more than approximately 20 miles from the transmitter site. In comparison, a full-power non-directional 50kW AM station can be received in C-QuAM stereo, where available, more than 200 miles from this transmitter site. Later generation HD Radio receivers should provide better usable sensitivity figures, to better receive the HD radio signals, under the widely varying reception conditions encountered in the field.
First adopters have stated that their HD radios will move back and forth, at their own will, from analog to digital modes. This is due to the received signal strength, and the need for each HD radio to use an outdoor antenna. When reverting back to analog, AM sound has considerably less fidelity in monaural, comparable to fidelity from an analog landline telephone connection. There have also been consumer reports, and personally verifiable evidence, that the HD signal eliminates reception of weaker first and second adjacent analog AM stations.
Critics have stated that the current HD Radio madness is a combination of low power, destructive interference, with artifact-filled audio, deaf receivers, and half-hearted programing. This is not exactly the best environment for radio stations and group owners to compete with the other consumer technologies for listeners.
Since there is a low bit-rate compressor / decompressor (codec) used in the HD Radio system, there are not two independent stereo audio channels, compared to C-QuAM stereo. There is steering logic that the receiver uses to move the sound between the left and right speakers. Also, all of the audio bits are not transmitted (compared to WAV files, or compact disk digital media). HD Radio's digital bit stream is compressed (turned into low digital bit-rates) prior to transmission. This reduces the delivery overhead and also conserves transmitted bandwidth.
New advances in transmitter design make HD Radio possible. Spectral re-growth is minimized, due to using better linear power amplifier transmitter stages. This also reduces the incidental carrier phase modulation, which also makes better C-QuAM stereo sound possible, with less harmonic distortion and wider AM stereo separation. Unfortunately, since HD radio uses phase modulation to deliver part of their digital signal, it infringes on the real estate of the C-QuAM analog stereo system. Therefore, HD Radio and C-QuAM technologies cannot co-exist on the same AM broadcast station.
From Thomas R. Ray III, Vice President/Corporate Director of Engineering, Buckley Broadcasting/WOR Radio, New York:
"The AM signal is composed of three parts, or blocks, of OFDM
carriers. The first block is -45dB down from carrier, and is
located from 0-5kHz, in quadrature with the carrier. The second
block is located from 5-10kHz, is -43dB, and is also in quadrature
with carrier. The third block is located from 10-15kHz, is -28dB
down, and amplitude modulates the carrier.
"The block under the audio carries station ID information, timing
information, text information and such. The block from 10-15K
carries the "primary audio", which is the mono audio. The block
from 5-10K carries the stereo information.
"Obviously, if the AM carrier goes away, so does the entire signal.
"That is HD transmission in a nutshell. ...
"In the all digital AM waveform, the primary carriers will occupy from
5kHz on the lower sideband to 5kHz on the upper sideband. The
secondary carriers move to the upper sideband at 5-10kHz. The
tertiary carriers move to the lower sideband at 5-10kHz. Level of the
primary is -15dBc (presently -28dBc). The level of the secondary
carriers becomes -30dBc (presently -43dBc). The level of the tertiary
carriers becomes -30dBc (presently -45dBc)."
As noted in the description by Thomas Ray above, in the hybrid AM digital/analog mode, the new OFDM carriers are significantly reduced in amplitude (and voltage) from the main analog carrier, hence the sensitivity issues encountered in the field.
Large media companies (such as CBS Radio and Clear Channel) own and operate many AM signals in many medium-size and large markets. As a suggestion, any under-performing AM radio format should be discontinued in a given market. Then the AM station should be converted to an all-digital HD Radio mode, and simulcast one of the remaining AM music-formatted stations. This may largely resolve the AM receiver sensitivity issues in the field. This experiment would also determine if listeners are really interested in the new HD Radio technology, and thus be motivated to purchase a new radio. ABC's Radio Disney AM station outlets should also convert to full-time HD Radio digital mode.
meduci has inquired into licensing iBiquity's HD Radio technology. However, we will not introduce new products until the receiver sensitivity issues are resolved. This should occur when stations suspend the analog/digital hybrid mode, and begin iBiquity's "all-digital, all-the-time" broadcasting mode.
"I've pretty much come to the conclusion that nobody cares. At least, nobody in charge cares. Okay, that's a gross generalization, but when I hear some of the stuff I've been hearing lately, it makes me feel like nobody cares.
"That isn't new, of course. For the last few years, I've heard and seen things going on in radio, some of which I've chronicled here, that made me feel that nobody was paying attention. This week, though, that feeling is just intensifying with each new head-scratchingly puzzling thing I hear. (And this is going to devolve into a rant about HD Radio, among other things, so if you're sick of that, you can skip ahead to the Talk Topics plug).
"Some of it is just sloppiness. The jock on a country station who stepped all over about 20 seconds of the vocals of some Taylor Swift song, well, either the guy had no idea how long he had, or something happened with the voice tracking... but since the song had a short intro, even a voice track should have hit the post. And, yes, I heard my share of dead air, weak and underdeveloped talk topics, unprepared personalities, and stop sets filled with PSAs and those painful "Radio Heard Here" things (I know, business is bad, but... wow, that sounds dire) that made me wonder if the PD or GM or Regional VP or anyone with a title was tuning in.
"But the worst of it came from my experience playing with one of those Best Buy portable HD Radios. Yeah, yeah, I know. But it's the cheapest and easiest way to get HD in my car, and since I can't get L.A. FMs at my house, that's the only way I can hear what they're doing on those HD subchannel things. And, despite the limited appeal of an FM-only radio in an age when even your keychain can play MP3s, store photos, and cook dinner, it's not a bad little device. In fact, I kinda like it. So when the local Best Buy finally started to sell them, I fought through the mobs of excited HD Radio purchasers and....
"Okay, there were no mobs. In fact, that's "Nobody Cares," Chapter 1: If you don't go searching for them, you will never find an HD Radio in the store. These were hanging on a forlorn pegboard all the way in the back of the store, next to the cassette and CD portables, which, sadly, is appropriate company. There were no signs. There were no other models. There was no attempt to educate consumers about the technology. They were just hanging there in the Ghosts of Technology Past department, without even a price sticker on the peg. I don't think the staff even knew they were there. All that stuff from the NAB and the Grand Exalted HD Radio Alliance about major marketing to get people to adopt, embrace, LOVE HD Radio? That's happening in another universe. I think they bought ads on the sides of unicorns. The first portable is out there, in the wild, and there's no marketing for it at all. Nobody cares.
"I hooked the thing up to my car radio, and I tried it out. That leads me to "Nobody Cares," Chapter 2: You can't hold an HD signal very long, and that leads to two critical problems. One, you know how the primary HD channel is supposed to cut back to analog when you lose the HD, and cut back to HD when it's available? On several stations in L.A. and San Diego, the analog and digital are not in sync. You're listening to a show and it... stutters. The switch from analog (underwater, bassy) to digital (bright, trebly) is hard enough on the ears; if the two streams are a couple of seconds off, it's impossible. You would think that the people at these stations would notice the problem, but there it was. Nobody cares.
"A bigger "Nobody Cares" problem, and one especially acute for talk radio, involves those "multicast" channels. Here's what the HD Radio marketing doesn't tell you: Those channels cut out all the time. You can't listen for very long. And it happens under all conditions. Try this: Clear day, driving along the freeway with line-of-sight to the Los Angeles antenna farm. We had one of the HD-2 channels on, and it would drop out not only while driving under bridges, but every few minutes without any apparent reason. It turns out that HD-2 and HD-3 channels disappear behind any obstruction -- hills, buildings, trees, other cars, Andrew Bynum -- and become unlistenable. They also disappear when there's no obstruction. And the next time I get a press release trumpeting how an AM station is now available on an FM HD-2 channel, I'll know the truth -- you're not adding a thing. The "multicast" channels are unlistenable. Nobody cares.
"While we're at it, a couple more multicast complaints -- I heard at least one talk station on an HD3 channel with volume levels that fluctuated so widely that it was impossible to listen for very long (the very lowest, hardest to hear levels were during the actual talk programming; the commercials were louder). Nobody at the station seems to notice. And another HD-2 music channel played the same song every time I checked in, a couple of hours apart; I was unaware of the existence of the All-Ting TIngs channel, and even a fan of "That's Not My Name" could tell you that you probably should throw in another song or two. Just sayin'. Someone should be spending some time making sure that the rotations work, but, after all, nobody's making any money on those channels, because nobody's listening, which is because nobody's being given a compelling reason to buy into the medium, which doesn't always work anyway. This could be fixed, but, well, nobody cares.
"Oh, and here's another "Nobody Cares": Proponents always promote the ability of stations to show title and artist information on the receiver's screen, a selling point against satellite radio. But when there's a syndicated show on, I've seen the screen display something like "NWN_2009_07_26_SEG1" for 20 minutes. I've seen one station stuck on "NEW_LEGAL_ID_OCT2008" with the name of the voice guy. Isn't someone at the station supposed to be checking that? I guess nobody is. Nobody cares.
"Look, maybe HD Radio isn't fixable, maybe radio has its problems, maybe you're not being paid what you want or you're in fear for your job, but that shouldn't mean the people who run and work in radio shouldn't take some pride in what they're producing. I think a lot of you do take pride, and there's still a lot of excellent information and entertainment being produced and distributed by radio people every moment of every day. But when I hear stations out of sync, dropping signal, changing volume levels, playing the same song over and over, screwing up the song display... clearly, somebody in charge is not listening to their own station. Someone should, because someone else cares: the listeners. Listeners care. I listen, and I care. And if you don't give me what I want, you're telling me to find another station, or another medium.
"Please... care."
What has been positive about the launch of HD Radio?
Stations have been allowed to upgrade their entire transmission chain, in many cases. Equipment that was used for decades has been discarded and retired, including very old analog playback devices, analog consoles, turntables, cart machines, cassette machines, DAT machines, CD players, MD players, analog processors, analog exciters, legacy analog-only transmitters, analog studio-to-transmitter-links, et cetera. Stations that upgraded to HD Radio have put considerable expense in implementing digital transmission and storage. Digital has been used in the audio chain after the microphone all the way to their new transmitters. Have listeners noticed? Do they care?
Equipment manufacturers have also greatly benefited by the HD Radio migration path. Stations probably will not institute another grand scale upgrade of this magnitude for another 40 years.
We understand the reasons why stations upgrade to HD Radio. We are living in a world where this is not your grandfather's radio. Today's listeners have many diverse choices competing for their attention. American radio stations feel compelled not to sit on their collective laurels, and not to be sleepy and complacent. They want to provide increased benefits to their listeners. They wish to fiercely compete in this new multimedia environment. Otherwise, the future for terrestrial radio may be very grim, as stations would face declining ratings (and revenue).
However, is HD Radio the saving grace for terrestrial radio? Or will it go the way of FMX, quad records, 8-track tapes, and Dolby FM? Only the future will tell.
Consumers have not widely embraced HD Radio to date. Many reasons persist:
* There are only (up to) two new channels available for each FM station transmitting HD Radio simultaneously with traditional analog.
* Audio quality deteriorates for all services as the iBiquity FM bit stream is split (further divided from one to two, then from two to three streams).
* Radios do not properly "fall back" to FM analog when the HD multi-cast disappears during signal fade. As a result, consumers are required to press a button on their radio in order for the station's audio to return.
* There is not any tangible benefit for AM broadcasters. Even the 50kW flame-thrower power-houses are relegated to digital service up to (approximately) 20 miles from their transmitter site locations!
* There are zero additional new channels available for each AM station transmitting HD Radio.
* Wideband AM HD Radio fidelity does not exist. True HD audio passband is up to 4 kHz. Audio frequencies above 4kHz are synthesized by the HD Radio codec. This conserves transmitted bandwidth. Ambience and high frequency stereo separation are lost. This results in artificial sound reproduction, that still cannot overcome external interference. And do not forget that the AM analog monaural sound channel needs to be cut back to 5 kHz (maximum top end) in order not to interfere with the new binary OFDM digital-generated AM HD Radio subcarriers.
* AM HD Radio critics have hailed how the AM HD carriers do not fit within the NRSC-2 passband and permissible FCC emission mask. If true, this would be illegal. However, iBiquity was careful to design these carriers to fit within the NRSC-2 mask. They took advantage of a "legal loophole," in that the NRSC-2 mask was never designed for continuous energy to be contained within the two outer (lower and upper) sidebands of any given AM radio station. Regular analog audio does not continuously splatter. There are momentary peaks encountered, as the station modulation hits 100%, where the audio may invade the first adjacent frequency. AM HD carriers are continuous in this spectrum. Analog AM radios interpret this continuous energy as a legitimate part of the analog transmission. Automatic Gain Control circuits amplify this continuous energy several fold, and the result is a very loud and distinctive "hissing sound" present on first and second adjacent frequencies to an AM HD radio station. This "hissing sound" steps onto the station's first and second adjacent neighbors. This is why the vocal AM HD Radio opponents are objecting, and referring to AM HD as flawed new technology.
* Wideband analog AM radios receive the third block of amplitude modulated frequencies from 10 to 15kHz, and the result is self-induced interference to the main channel analog audio. Signal-to-noise ratio is decreased, and it is even more difficult to listen to AM broadcasts on these wideband analog radios.
* People are voting with their wallets. MP3 players (iPods and such), and satellite radio sales are up. HD radio sales are down. Also, 70 percent of new cars sold now offer an auxiliary audio input jack on their radios, ready for connection to MP3 players and other external devices.
* Radio stations are not generally promoting their HD services very well, except at the top-of-hour legal station identification. When HD is being promoted, consumers are still confused. When consumers hear the letters "H-D," they asume that the station upgraded their facility, so that their current analog radio will sound better. Many listeners do not know that their existing radio needs to be upgraded (at their own cost). It seems that this additional expense is being downplayed by the media companies.
* There is a prevalent general "Who Cares?" attitude among listeners, when they are given the choice of hearing multiple FM HD Radio streams. Their perception is that existing analog radio sounds fine to them. Why make the financial upgrade to digital? And we will not discuss what listeners perceive of AM HD Radio.
Since consumers largely feel that analog FM stereo fidelity is acceptable, we suggest that FM stations discontinue the simulcast of their analog signals on FM HD-1. Instead, use this HD-1 channel at each FM station with HD-2 and HD-3 to create three independent additional sources of programing (and hopefully, additional revenue streams) to complement the terrestrial analog signal. This may require a field firmware upgrade to the HD Radios to receive analog broadcasting, independent of the digital HD channels.
Cox Broadcasting is making a conscious decision not to allow self-induced interference and reduced audio modulation on their AM stations, when these same stations are already competing to be heard over other increased man-made and natural noise sources.
It is with great sadness that we report the passing of Edwin Buterbaugh (pronounced Boo-ter-baw), on September 1, 2008 from a four-year bout with bladder cancer. Ed was 65 years old, and longtime Director of Engineering at WJR-AM in Detroit, Michigan. Ed was directly responsible for maintaining the legendary AM stereo sound heard at WJR. Twice he completely rebuilt the WJR studios, once in 1987 and again in 2001. He was instrumental in ensuring that all WJR remote live broadcasts were transmitted in stereo, including the annual Thanksgiving Day parade on Woodward Avenue in Detroit. On a personal note, it was absolutely awesome to listen to the many Detroit Tigers baseball and Red Wings hockey broadcasts in stereo, as well as the Thanksgiving Day parade broadcasts. It was not easy to capture the crowd noises, ambience, press box, and other sounds, backhaul it from Detroit to Riverview's transmitter, and then transmit it on the 50kW high power "The Great Voice of the Great Lakes" radio station. For those who were able to hear those historical live AM stereo broadcasts, it was as if you were there at the stadium, directly in the middle of the action! It was also during Ed's tenure, that their Motorola C-QuAM stereo generator was overhauled, and all of the electrolytic capacitors were replaced in the unit. As a listener to WJR's AM stereo sound almost since the beginning, until its end on October 26, 2005, I know that Ed was very proud of the wide stereo separation and lightly processed air chain that he engineered. Ed's passion for quality AM stereo sound will be missed! There are not many chief engineers like him that share that passion. Mike Fezzey, WJR's President and General Manager, says, "Ed has led us through rebuilds, build-outs, blackouts, uplinks, downlinks, installs, re-installs, AM stereo, transmitter installations, digital conversion and more." Ed retired from WJR in 2004 after 20 years. WJR's Creative Director John Marshall reflects back on Ed's life. You can listen now by clicking here!
Prior to arriving at WJR, Ed engineered the signature sound for 13 years at CKLW-AM "The Big 8" (Windsor, Ontario) in its heyday as a 50kW Top 40 popular music station. He was responsible for the booming midrange-heavy music heard from many portable transistor radios of that era. One day at CKLW, Ed decided to remove the coupling capacitors (in order to likely improve the low bass frequency response), and accidently reduced CKLW's output power to 25kW! He later realized that removing the coupling capacitors allowed DC voltage to ride on top of the audio to the transmitter's modulator stage. This DC voltage shift caused the voltage bias of the transmitter to change, resulting in the reduced power output. Ed said that it could have been worse, had the voltage went in the other direction, causing the transmitter output to exceed 50kW. Ed was also responsible in 1979 for testing the Harris V-CPM AM stereo system at CKLW. Ed produced a 52-page report detailing his findings from the tests. It covered channel separation (as affected by directional antenna systems), adjacent channel interference, directional antenna null protection, distortion in monaural receivers, skywave effects, compatibility, frequency response, distortion, and signal-to-noise ratio.
It was my love of AM stereo that prompted me to attempt to listen to WJR stereo in November 1982 using the "two radio" trick. I did not hear much stereo separation, though the sound was definitely phased in different directions from the two radios. WJR was a heritage station and class act that truly believed in the C-QuAM technology. There was a definite commitment from WJR to transmit good high quality stereo sound to their listeners. Stereo programing included the music magazines Kaleidoscope and Patterns In Music, which focused on various music genres, themes, and eras, hosted by Mike Whorf on Sunday mornings. WJR was one of the few C-QuAM stereo pioneer stations. And those many stereo remote live broadcasts were not easy to put together. Ed's commitment to quality sound inspired me to research, develop, engineer, and to introduce the first AMX2000 stereo tuner in mid-2005. All of our AMX2000 tuners are now dedicated to you, Ed.
meduci, LLC is a highly entrepreneurial and innovative organization that specializes in custom freelance engineering, design and production of electronic products in prototype quantities to full scale manufacturing. We also design low frequency (class A, class AB, class D) audio power amplifiers, class C power R.F amplifiers, and R.F front-end (amplifier, mixer, oscillator), using National Semiconductor, Motorola, and other custom ASIC chipsets and discrete components. We strive for quality and excellence in workmanship. Our products are designed for faithful sonic reproduction of the on-air source material. For customers with specific requirements, you could always count on us to produce innovative solutions. Our customers are benefited by better pricing, quality warranty, and excellent technical support. Contact us for a free quotation -- we appreciate your business. Our goal is to meet the needs of our buyers, distributors and dealers, and we can work on an ad hoc basis.
Access statistics provided by 