HD Radio

[RedWingCJS278]

WBZ is also on WBZ-FM-HD3. And it sounds much better than WBZ(AM)HD.

Hmmm, to each their own. I find 1030 HD is superior sounding to 98.5-3, and a more reliable signal. The AM is in stereo, while HD3 is only mono. There's also the matter of the time delay on the HD3. The HD3 will also sometimes have reception issues, though not often - 98.5 is a great signal, and HD1 & HD2 are flawless. 1030 is a monster signal, and the HD performance is spotless. Of course, I'm within 128, but I'd have to imagine that if one is at least within 495 then they shouldn't have a problem with WBZ HD reception ... as long as their radio is working properly. And therein lies the rub, too many of the HD models on the market have numerous bugs that prevent optimal performance. My Sony unit has worked well for me - easily the best radio I have ever owned by any measure - but I don't know how many years longer it will be before it's HD functions will be rendered useless. I've come to the conclusion that HD radio just doesn't have much of a future. Too many flaws and virtually zero public interest. Might as well enjoy it while it lasts, and not worry about it. 1030 in HD, Radio Mojo, and the 102.5 Classical Country HD2 make it worthwhile for the time being. But, if anyone is going to purchase an HD radio, they would be best advised to do their research, and remember that one gets what they paid for.

 

[aerie]

I wonder if the FCC will ever require radio manufacturers to include HD capability? I remember how FM and UHF-TV didn't do very well until manufacturers were required to include the FM band on every radio and a UHF tuner on every TV. Considering how AM stereo was not much of a success because of competing systems and the "let the marketplace decide" mentality, I wonder if the FCC will intervene? I think HD would do very well if the equipment was more readily available, especially for car audio systems, but I am not sure the government should step in.

 

[Jimmy128]

Speaking of the FM band, I read somewhere that there is talk of extending FM to begin at 76.1MHz. Anybody know anything about this?

 

[Deleted User]

Japan uses 76 to 90 Mhz as their FM band, which is where VHF channels 5 and 6 are in the U.S. Spectrum.

Below 76 is out because of the use of some 75 Mhz frequencies are currently used as navigation aids.

One problem is there is a move afoot at the FCC to grab UHF above channel 52, the same way they grabbed channels (73 to 83 IIRC for Cell Phones) years ago.

If they grab that part of the spectrum for more lucrative uses ( wireless internet) they may force some TV stations back onto VHF which has not worked out real well for broadcasting DTV.

IMHO the FCC doesn't give a rats backside about broadcasting anymore, all they want to do is carve up the broadcast spectrum for newer technologies that will pay more for licenses and use less space. If you can get a whole boatload of money out of breaking up 6 mhz into a bunch of smaller allocations why would you give a damn about the existing technology. It isn't like the FCC is doing anything about pirates, which proves they don't care.

 

[Deleted User]

P.S. the problem with the FCC mandating or "type accepting" HD radio as a condition of certifying a radio under Part 15, is that the HD radio technology is proprietary, and forcing stations to broadcast it, or radio manufacturers to include it is that it is going to drive the cost of consumer electronics up.

The FCC screwed up by not using an open source technology for HD radio IMHO

This is my same gripe with the push to make "cell phones" have FM tuners in them. Why stop there how about AM and HD too? Why not a TV tuner in there too as many of the smart phones already have the displays for 720 or 1080 dpi resolution. By mandating it, they are just driving the cost to the consumer up.

I do remember when UHF tuners were not mandated in TV's. I remember when the UHF tuner was far inferior to the quality of the VHF tuner ( air ganged capacitive UHF tuner compared to the individually tuned circuits for VHF). Eventually the FCC required all tuners to be of equal quality. I also remember when FM tuners became mandated in car radio's, no more AM only.

 

[aaronread]

Hmmm, to each their own. I find 1030 HD is superior sounding to 98.5-3, and a more reliable signal. The AM is in stereo, while HD3 is only mono.

It's been a few months since I checked (via skywave, WBZ comes in quite well at night here in upstate NY) but WBZ 1030AM transmits in HD Radio, right? If so, the iBiquity HD Radio transmission system is incompatible with AM Stereo. The HD-AM signal is in stereo, but the analog has to be mono. IIRC, the backup transmitter in Hull is indeed C-QUAM AM Stereo. But the primary isn't. I think the third backup (10kW from the tower next to the studios in Brighton) is also mono-only but I'm not positive about that.

IIRC, the only AM station in Boston since in C-QUAM AM stereo was/is WJIB 740AM. But I haven't checked that since 2007.

The FCC screwed up by not using an open source technology for HD radio IMHO

I could write a book about the history of IBOC, but in direct response to your comment: the genesis of Digital Audio Broadcasting in the USA traces back well over 20 years...long before "open source" was even coined, much less a viable concept for wireless communication. It also cost the companies, that eventually became "iBiquity", in the billions of dollars for R&D. Not too many open source concepts had (or have today) the resources necessary to design an IBOC DAB solution from the ground up.

Plus the FCC (and the NRSC-5) have always had visions of the disaster that was AM Stereo with its "let the marketplace decide" approach. So I think a true "open source" solution would've been anathema.

I also remember when FM tuners became mandated in car radio's, no more AM only.

That's a common misconception. (I used to think it was true myself until challenged on it a year or two ago) The FCC never REQUIRED that radio tuners receive both AM and FM. That was purely a market-driven system.

 

[xyz]

Context. IBOC currently transmits at 1% analog power. 1030 is 500 and 1260 is 50 watts digital. Both signals are being reamed -- in the choicest part of their trellis -- by analog dinosaurs 100 times more powerful. FM digital? 88 - 108 mhz ain't even gonna use FM anymore. They will use an xxxQAM scheme similar to TV and AM. IBOC is very much worth waiting for!

 

[Eli Polonsky]

Hmmm, to each their own. I find 1030 HD is superior sounding to 98.5-3, and a more reliable signal. The AM is in stereo, while HD3 is only mono.

It's been a few months since I checked (via skywave, WBZ comes in quite well at night here in upstate NY) but WBZ 1030AM transmits in HD Radio, right? If so, the iBiquity HD Radio transmission system is incompatible with AM Stereo. The HD-AM signal is in stereo, but the analog has to be mono.

Aaron, he meant that the AM HD is in stereo (not the AM analog), as compared to the FM HD3 which is mono. As far as I know, all FM HD3's are mono, but AM HD is stereo.

IIRC, the only AM station in Boston since in C-QUAM AM stereo was/is WJIB 740AM. But I haven't checked that since 2007.

WJIB has not been in stereo since around 2007, when a severe voltage spike caused by an error made by NSTAR workers in the area fried the AM stereo transmitter. After switching to a mono backup, Bob Bittner decided not to bring back AM stereo. There are now no analog AM stereo signals receivable in the Boston area that I know of, WJIB was the last one.

 

[wcozBoston]

The FCC could have made HD radio even better by putting the HD transmitters on the VHF high TV band between 175 and 216 MHz. This would be a good technical solution on many fronts:

1. Gives the opportunity to allow 24 hour operation by restrictive directional and daylight only AM stations
2. As HD gains popularity, restrictive AM transmitters could eventually drop off the air and just use just their HD signal
3. Would allow more clear channel AMs as restrictive AMs drop off the air for those stations wishing to remain on AM
4. Eliminates HD interference received on traditional analog FM receivers
5. Gives daylight AM stations the opportunity to eventually compete with big signals AM and FM stations

So for example, WILD could run a full market HD transmitter at 192.7MHz, and eventually drop the the 1090 AM signal enabling WBAL to operate without interference from WILD.

 

[aaronread]

Aaron, he meant that the AM HD is in stereo (not the AM analog), as compared to the FM HD3 which is mono. As far as I know, all FM HD3's are mono, but AM HD is stereo.

Ah, gotcha. That is correct that AM IBOC is inherently stereo, although that doesn't mean WBZ is actually putting stereo content out there. I would imagine most of their content is mono given that they're a news/talk station. :

There is no requirement than an HD3, or any HD-n multicast channel, be mono. It's just a limitation of bandwidth. IIRC if you run a multicast channel at 24kbps or less, it defaults to mono. (I think 24 is the cutoff...I could be mistaken and it's 20, though...don't remember off the top of my head) Several FM IBOC stations are using extended hybrid mode and you're limited to 24kbps in that zone, but it allows you to run 48/48kbps on your HD1/HD2, and 48kbps is a lot more forgiving than 32kbps when it comes to audio fidelity and the HDC (aka AAC) codec. Certain formats will sound fine at 32 natively, and virtually all will sound fine with proper preprocessing. But it's still easier at 48kbps.

BTW, I don't know for sure if WBZ-FM is running extended hybrid or not. It's possible they're running normal hybrid, split 48/24/24 for their HD1/2/3 for all I know. Or 48/32/16.

The FCC could have made HD radio even better by putting the HD transmitters on the VHF high TV band between 175 and 216 MHz. This would be a good technical solution on many fronts:

Oh everyone knew from the beginning, even way back in the 1990's, that new spectrum would be a better way to go for migrating radio from analog to digital. But it wasn't going happen: spectrum is far, far more valuable when used for two-way communication as opposed to one-way like radio and TV. TV is too data-intensive for an IBOC solution to work, but it was theorized that IBOC was possible for radio...so we, as an industry, spent billions and 20 years building a solution that wasn't necessary except for politics. Hey, I give HD Radio credit: for something that shouldn't have been necessary, it's actually a pretty nifty system. But yeah, it's frustrating how often politics trumps engineering.

Hell, just last year, with the release of the National Broadband Plan, we learned what many of us in the broadcast industry have long suspected: the FCC officially plans to sacrifice broadcasters at the altar of wireless internet. Sigh. :-\

There are now no analog AM stereo signals receivable in the Boston area that I know of, WJIB was the last one.

Pity! And the irony is that a lot of HD Radio receivers will decode C-QUAM AM stereo quite nicely. Few of them announce it on their specs, though.

 

[Eli Polonsky]

Aaron, he meant that the AM HD is in stereo (not the AM analog), as compared to the FM HD3 which is mono. As far as I know, all FM HD3's are mono, but AM HD is stereo.

Ah, gotcha. That is correct that AM IBOC is inherently stereo, although that doesn't mean WBZ is actually putting stereo content out there. I would imagine most of their content is mono given that they're a news/talk station. :

Certain elements like bumpers, background beds, and many of the commercials are in stereo on WBZ (AM) HD, but most of the programming content is essentially mono.

The other two Boston area AM stations currently in HD are WMKI 1260 and WKOX 1430. It sounds like WMKI, a full-time "Radio Disney" affiliate, is broadcasting that network feed in mono, but I get full stereo separation on the Spanish music format on WKOX.

 

[Rusty Muck]

why does WBZ have 5khz of empty space betwen their lowpassed analog signal and the data sidebands?

are they deliberately making the AM sound bad so people will want HD?

No, all AM stations that run HD have their analog high end filtered off really low. I don't know the specifics, but I believe it's claimed that broadcasting higher analog frequencies could interfere with HD reception of the digital sidebands on AM.

Interestingly, when WTAM in Cleveland has to turn off their HD tx (it was off last night into today) the main analog signal actually has a 10kHz bandwidth. Or something close to it. Do note that WTAM had operated their analog signal with a 5kHz bandwidth for nearly two years prior to adopting the hybrid standard.

In addition, when WJR in Detroit utilized the hybrid broadcast - before Citadel ditched it on almost all of the legacy ABC Radio AM stations - the analog was first tuned to 5kHz, but then was readjusted back to 10kHz on the hybrid. Or something close to it, as the analog didn't even sound muddled and rather bright, but you could tell that the hybrid was in operation. And this was picking up the station in Cleveland (which technically is within WJR's main coverage area).