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IS HD the way to go for AM PHILLY STATIONS?
- Thread starter joshzz
- Start date
F
FredLeonard
Guest
No! Gawd No!
IBOC hash drives away listeners.
HD units have very low market penetration (few people have one, or want one).
HD AM reception is problematic.
Excluding religious broadcasters, the major AM station owners also have FM stations in this market. FM sub-channels are a better option. FM main channel better yet.
The audience for AM formats tend to be late adopters; they are likely to be the last to buy any new product - even one with buzz, which HD Radio does not have.
IBOC hash drives away listeners.
HD units have very low market penetration (few people have one, or want one).
HD AM reception is problematic.
Excluding religious broadcasters, the major AM station owners also have FM stations in this market. FM sub-channels are a better option. FM main channel better yet.
The audience for AM formats tend to be late adopters; they are likely to be the last to buy any new product - even one with buzz, which HD Radio does not have.
K
KC2LDY
Guest
For all the reasons stated above, absolutely not. HD radio is essentially a non-starter even for FM radio, never mind AM. Some people in the industry and enthusiasts who visit this website might be interested in HD radio. But the honest truth is the general public doesn't care - and most people are completely unaware of it.
HD radio was first proposed when the industry was fearful of competition from satellite radio. But that threat never really materialized. And now, even the broadcast companies are unenthusiastic about HD radio - even for FM. Broadcast radio's digital maturity will probably manifest itself in online streaming, which will grow as wi-fi networks continue to grow and smartphone data plans become less expensive.
As much as it pains me to say this, I'm not sure there is a long-term solution for AM anymore. Note that the major broadcast companies are beginning to move their mainstream formats - even talk formats - over to FM. Sure, there's often simulcasting for a while. But ultimately, the AM signal will either be cast off or used to clear a national format that needs spot clearances in a given market.
Remember the years 2012 and 2013. When we look back, we'll remember them as the years when the abandonment of the Standard Broadcast Band began - at least for mainstream formats. Look for AM to be populated by religious, ethnic and brokered-time stations for a few decades before the FCC finds an excuse to shut the band down for broadcasting and use the spectrum space for something else.
Steve
KC2LDY
HD radio was first proposed when the industry was fearful of competition from satellite radio. But that threat never really materialized. And now, even the broadcast companies are unenthusiastic about HD radio - even for FM. Broadcast radio's digital maturity will probably manifest itself in online streaming, which will grow as wi-fi networks continue to grow and smartphone data plans become less expensive.
As much as it pains me to say this, I'm not sure there is a long-term solution for AM anymore. Note that the major broadcast companies are beginning to move their mainstream formats - even talk formats - over to FM. Sure, there's often simulcasting for a while. But ultimately, the AM signal will either be cast off or used to clear a national format that needs spot clearances in a given market.
Remember the years 2012 and 2013. When we look back, we'll remember them as the years when the abandonment of the Standard Broadcast Band began - at least for mainstream formats. Look for AM to be populated by religious, ethnic and brokered-time stations for a few decades before the FCC finds an excuse to shut the band down for broadcasting and use the spectrum space for something else.
Steve
KC2LDY
F
FredLeonard
Guest
Steve Biro said:
You called it Steve.
The niche AM might reasonably fill is in sparsely populated regions, especially those between the Rockies and the Appalachians, where clear channel and regional stations can cover a large territory. Clear out the dead wood on the AM band, all the daytimers and local frequency stations; maybe even let clear channel stations go to super power (like WLW once did). These stations could provide a useful service in under-served area. That's why clear channel stations were set up in the first place. They'd have to forgo satellite and voice tracking and really focus on serving their regions (the way radio stations used to do). Without the kind of interference you find in metro areas, they could put listenable signals. But better do this quick, before somebody decides you can do the same with FM repeaters on one frequency (like they do in Europe).
They've done this 100% digital testing on CBS O&O. With mixed results. In the car, outdoors it was fairly good distance with nearly the same coverage as analog. What's NOT mentioned in this article is that Ibiquity was somewhat embarrassed, and said they themselves would work on a new antenna design for INDOOR reception. To me, reading between the lines, it meant two things. Signal penetration into the house and office even at 10Kw didn't do the trick to cover the damn noise floor of interference in 2013. There is so much hash from chargers, computers, dimmers, cable boxes, modems, internet wifi transmitters, CFL, and even worse, LED screens & light bulbs, so much Part 15 noise, it spikes into a solid digital modulation, causing it to constantly buffer and breakdown.
Also, according to Ibiquity in RW, the penetration of HD as of the end of the year was at 12 million units. 12 million US & Canada. Lower than FM, 50 years ago. Here's the story Dory:
http://rwonline.com/article/more-all-digital-am-tests-planned/218248
Also, according to Ibiquity in RW, the penetration of HD as of the end of the year was at 12 million units. 12 million US & Canada. Lower than FM, 50 years ago. Here's the story Dory:
http://rwonline.com/article/more-all-digital-am-tests-planned/218248
Steve Biro hits it, and Fred really amplifies it. I remember when when some of the big guns like WLW, WSM, and a couple of others wanted to go to 750 kW. With the noise floors being what they are now, increasing field strength 3.87-fold doesn't seem so far fetched. But in cases of adjacent-channel operations like KDKA/WBZ,and WEPN/KYW, there might need to be lesser power levels and/or tighter directional patters to ease overlap. There was a case in Europe not long ago where the BBC shut down its 500 kW World Service to Europe on 648 kHz. It was recently revived as the directional pattern put a near-local quality signal into the Netherlands, and the Dutch national broadcaster now uses it.
Any system such as AM HD that generates noise and interference is certainly a flawed system and should not be used. And this comes from a retired engineer who was in radio for 45 years.
Doesn't HD offer unparalleled sound quality that would afford an AM the pure & clean high quality sound that FM listeners expect from radio? Based on your indepth responses there are serious issues with HD but still wouldn't it give me an advantage as the technology becomes more accepted with radio users? Your thoughts are appreciated?
F
FredLeonard
Guest
josh said:
Unparalleled? Not really. Better, when you can get an HD signal lock.
Problem is HD is not being accepted with radio users. Look at all the buzz surrounding new phones, new tablets and other product releases. HD radio doesn't even rate a yawn. I went shopping for an new car radio at Best Buy. Since I was shopping anyway and since I follow radio more than most people, I asked about HD. The sales guy dismissed it and recommended against it. He said people who had gotten one came back and said they didn't like it.
HD is solving a problem few people have. People in the money demos don't listen to AM because they never listened to AM. Not because of sound quality so much but because growing up, their music was on FM. But I never had a problem with AM. KYW, WPHT, WIP and all the other major AM stations sounded fine for talk. New York stations have more noise on the car radio than they used to but HD doesn't help there.
Bottom line: If I have a good analog AM signal, I can get higher fidelity. Not a big deal for a spoken word format. If I don't have a good signal, I can't get AM HD at all. It doesn't get rid of static. It creates static. 860 seems to have shut off IBOC but for a time they were the reason I couldn't listen to Newsradio 880. So, no real pluses and some big minuses.
Doesn't seem like we are giving you the answer you're looking for. Sorry.
Any possibility that the FCC will change Am so that it has the same attributes of days gone by? I was told the fidelity was much better in the 60s and 70s but the FCC made some kind of change that adversely affected sound quality. As I recall, during the 70s some stations were broadcast in stereo. Are we able to go back to better times?
The home radios and car radios of that era were better-sounding, Josh. And some of those home radios -- the 'barbershop' models -- were made to last. The tubes seemed to give the sound that added spice.
And there had been a study vis-a-vis WQXR-FM in NYC and WQXR-AM in New York City. Quite elaborate, as I recall. The differences in sonics were not all that different. But the AM listening was done on a well-equipped tube radio.
True, today, there are some AM sections in car radios that sound splendid. But the newer car-radio consoles come with enough other audio options to embarrass whatever sonics AM has to offer.
And there had been a study vis-a-vis WQXR-FM in NYC and WQXR-AM in New York City. Quite elaborate, as I recall. The differences in sonics were not all that different. But the AM listening was done on a well-equipped tube radio.
True, today, there are some AM sections in car radios that sound splendid. But the newer car-radio consoles come with enough other audio options to embarrass whatever sonics AM has to offer.
F
FredLeonard
Guest
Steve, you've given me an idea. What if somebody built an AM/FM radio from old time spec and old time schematics? Tubes. Heavy plastic or even wood case.
Problem, of course, nothing but right-wing talk, news in a few markets, preachers and infomercials to listen to.
Problem, of course, nothing but right-wing talk, news in a few markets, preachers and infomercials to listen to.
The problem with the "Barbershop" models is that the W. German imports had narrowband AM IF sections. In Europe, the AM staions are seperated by 9Kc, not 10Kc like they are in North America, and the AM audio is narrow and muddy. The FM's however, were pretty spectacular.
As far as AM noise supression and tubes: There IS a circuit that RCA pioneered in its' Camden plant and began selling in 1959. It was on their better radios, caller "Filteramic". It was a noise blanker, but it didn't narrow the bandwidth. I just repaired a 1965 AM/FM model. I was SHOCKED when it was placed on the table next to the laptop, and picked up everything unmolested by the light dimmer, charges, power supply, led screen, CPU processor, etc. Just LOOK at this short video of this 1960 AM-only model...right next to an LED screen..no noise.
http://www.youtube.com/watch?v=YY1SLCzhoKk
Thoughts?
As far as AM noise supression and tubes: There IS a circuit that RCA pioneered in its' Camden plant and began selling in 1959. It was on their better radios, caller "Filteramic". It was a noise blanker, but it didn't narrow the bandwidth. I just repaired a 1965 AM/FM model. I was SHOCKED when it was placed on the table next to the laptop, and picked up everything unmolested by the light dimmer, charges, power supply, led screen, CPU processor, etc. Just LOOK at this short video of this 1960 AM-only model...right next to an LED screen..no noise.
http://www.youtube.com/watch?v=YY1SLCzhoKk
Thoughts?
Isn't the other problem with today's AM transmission the reduced analog bandwidth that AM/HD stations have to use to stay within the IBOC mask? If I recall correctly the current analog bandwidth employed by AM stations running HD is around 5khz. If that is the case, it's no wonder AM sounds "bad". Even with NRSC I remember AM sounding pretty good when the bandwidth was out to 8 to 10khz. Of course as mentioned today's receivers are as much at fault these days as any other factor.
Here in Dallas we are lucky to have a few "Mom and Pop" local owner/operators programming niche music formats such as Gold (50's-70's) Standards/Big Band, and a good old fashion KVIL like A/C. These stations are NOT HD equipped, do not have the severe analog bandwidth restrictions, and as a result sound remarkably good. As good as AM stations sounded in the 60's and early 70's. There only issue is signal to noise ratio as each station's carrier power is 500 watts or less daytime, even lower at night. Listening close in, they sound remarkable, fringe not so good....
I listen to these full bandwidth Mom and Pop AMs on a late 40's National NC240D with the bandwidth set at 10kc and they sound great. Even on the crappy factory in-dash in my Mazda CX-7 the difference between the analog bandwidth restricted stations and the full bandwidth stations is pretty remarkable.
Jay Walker
Here in Dallas we are lucky to have a few "Mom and Pop" local owner/operators programming niche music formats such as Gold (50's-70's) Standards/Big Band, and a good old fashion KVIL like A/C. These stations are NOT HD equipped, do not have the severe analog bandwidth restrictions, and as a result sound remarkably good. As good as AM stations sounded in the 60's and early 70's. There only issue is signal to noise ratio as each station's carrier power is 500 watts or less daytime, even lower at night. Listening close in, they sound remarkable, fringe not so good....
I listen to these full bandwidth Mom and Pop AMs on a late 40's National NC240D with the bandwidth set at 10kc and they sound great. Even on the crappy factory in-dash in my Mazda CX-7 the difference between the analog bandwidth restricted stations and the full bandwidth stations is pretty remarkable.
Jay Walker
Jay, the band is audio limited to 10kc, with the drop-off at 9. I just read my Engineering version of Radio World, with another call to lower the bandwidth to 7Kc. Are these guys nuts? I'd like to see ONE call to limit FM frequency response to 7Khz!
There was indeed a time when AM was full fidelity, transmit and receive. There were many High Fidelity receivers about. Many had wider bandwidth on AM than the FM side, especially Zenith and RCA. The FM was full of hiss, and they just filtered it out.
The RCA BTA AM series transmitters were high fidelity. The Gates Vanguard was exceptional. http://www.oldradio.com/archives/hardware/Gates/Vanguard.htm 20-20Kc!
There was indeed a time when AM was full fidelity, transmit and receive. There were many High Fidelity receivers about. Many had wider bandwidth on AM than the FM side, especially Zenith and RCA. The FM was full of hiss, and they just filtered it out.
The RCA BTA AM series transmitters were high fidelity. The Gates Vanguard was exceptional. http://www.oldradio.com/archives/hardware/Gates/Vanguard.htm 20-20Kc!
amfmsw said:
I understand that the analog bandwidth (no HD) is normally 10kc. But I'm pretty certain that the analog bandwidth is reduced to 5khz on some stations when the HD mode is in use. This is so stations HD carriers remain within the mask.
Here's a quote from a NRSC "White paper from 2007 about that..
"Nearly twenty years later, in 2004, as part of a review of the NRSC’s AM bandwidth standards, the NRSC’s AMB Subcommittee recognized that some broadcasters were reducing the audio bandwidth of their analog AM signals from the 10 kHz specified by the NRSC standards to 5-6 kHz, in an effort to further reduce interference in the band, and with the understanding that most consumer receivers are bandlimited to 5 kHz or less. Further, this bandwidth reduction was being done independent of the bandwidth reduction required when a broadcaster elects to transmit a hybrid AM in-band/on-channel (IBOC) digital radio signal."
Link:
www.nrscstandards.org/DocumentArchive/NRSC-G100.pdf
I own several vintage AM broadcast transmitters I use for Amateur Radio including a 1941 Western Electric 451A, A Gates BC1T, BC1H, RCA BTA-250M and have converted many RCA BTA-1R series. When I run these transmitters on a dummy load and listen with a receiver capable of wide-band AM reception the fidelity rivals Mono FM.
My processing in it's various forms includes an Optimod AM, several versions of the Volumax/Audimax, CRL, PR&E Multi-Max and the Dorrough 210 AM Stereo Limiter. I'd stack the audio quality of any of my old transmitters up against a Mono FM. But again my bandwidth is not restricted to 5kc, err I mean 5khz ;D...
The Gates Vanguard One was an interesting transmitter, but I had heard they were prone to catching fire. Because of the small chassis the heat buildup was incredible. It was a weird little design that looked very similar in size and shape to a Seeburg Jukebox. It used a solid state 100 watt exciter driving a single tube 4CX3000 amplifier.amfmsw said:
Another great sounding transmitter was the 5kw Continental "Power Rock" 315-R1 (Rockwell-Collins 828E-1) and it's baby brother the 1kw "Power Pebble" 314-R1 (Rockwell-Collins 828C-1). I installed a Power Rock 5kw transmitter back around 1976 and was absolutely astounded with how incredibly low the distortion was. The frequency response was excellent, essentially flat out to 10khz with no low frequency tilt. Made me a firm believer in PDM for sure. That transmitter would hang at 124% positive and 99% negative 24/7 and never break a sweat.
But if efficiency is not an issue, as you mentioned, you can't beat the early High Level Plate Modulated transmitters of the late 40's through the early 60's for fidelity and that certain "silkiness".
Since AM directional arrays have to be broad-band to be suitable for HD transmission, there is no reason why today's analog AM can not provide near FM audio frequency response. Man made noise can be reduced on the receive side with current DSP technology but Lightning will always be a negative factor.
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