I finally got to hear HD Radio (a.k.a. IBOC) on several Boston FM's
Saturday night (but not any AM's since it was night). My observations:

1. HD Radio does not sound appreciably better than FM.

2. On some of the stations there was a "gritty" quality to the sound
reminiscent of an MP3 Internet stream. To be fair, this could have
been the result of cascading HD Radio with an STL or digital audio
storage system employing something like MPEG or apt-X compression,
and not something inherent in HD Radio itself.

3. HD Radio does not appear to extend a station's coverage. On the
fringe of one station's coverage, where it could be heard in analog
FM imperfectly, the HD Radio was generally not audible at all. We
estimated that the effective range of the HD Radio signal is 90 to
95 percent of that of the analog FM.

4. The Kenwood receiver seems to mute in digital mode if there is
another signal on an adjacent channel.

5. It also mutes in the presence of nearby FM transmitter sites.

6. In analog mode, the digital sidebands of a station running HD
Radio can be heard as white noise. It is not yet possible to
guess how much interference they may cause because only a few
stations are running HD Radio yet.

7. The scrolling text display some stations were running may be a
considerable distraction to drivers.

After hearing some glowing reviews, I was prepared to hear something
approaching the sound of a CD and to want to push to put it on
our stations. Instead, my friends and I were asking ourselves why
anyone would want to pay $75,000 for it.

However, I am still reserving judgment. One night of listening on
one radio isn't enough; I want to hear it on several different
radios on a wider variety of stations, under different reception
scenarios. I'm particularly interested in the effect of adjacent-channel
interference.


umar

Hi,
How does HD radio work? I'm an equipment designer (remote control
equipment) from Italy, we don't have it here. Never even heard about it! Is
it Digital? Modulation CODFM? what is the bandwith? Here in Italy we have
DAB... do you have that in the US?
thanks,
Mario.


"umarc" ha scritto nel messaggio
...
I finally got to hear HD Radio (a.k.a. IBOC) on several Boston FM's
Saturday night (but not any AM's since it was night). My observations:

1. HD Radio does not sound appreciably better than FM.

2. On some of the stations there was a "gritty" quality to the sound
reminiscent of an MP3 Internet stream. To be fair, this could have
been the result of cascading HD Radio with an STL or digital audio
storage system employing something like MPEG or apt-X compression,
and not something inherent in HD Radio itself.

3. HD Radio does not appear to extend a station's coverage. On the
fringe of one station's coverage, where it could be heard in analog
FM imperfectly, the HD Radio was generally not audible at all. We
estimated that the effective range of the HD Radio signal is 90 to
95 percent of that of the analog FM.

4. The Kenwood receiver seems to mute in digital mode if there is
another signal on an adjacent channel.

5. It also mutes in the presence of nearby FM transmitter sites.

6. In analog mode, the digital sidebands of a station running HD
Radio can be heard as white noise. It is not yet possible to
guess how much interference they may cause because only a few
stations are running HD Radio yet.

7. The scrolling text display some stations were running may be a
considerable distraction to drivers.

After hearing some glowing reviews, I was prepared to hear something
approaching the sound of a CD and to want to push to put it on
our stations. Instead, my friends and I were asking ourselves why
anyone would want to pay $75,000 for it.

However, I am still reserving judgment. One night of listening on
one radio isn't enough; I want to hear it on several different
radios on a wider variety of stations, under different reception
scenarios. I'm particularly interested in the effect of adjacent-channel
interference.


umar

"Mario dei Pintarei" writes:

How does HD radio work? I'm an equipment designer (remote control
equipment) from Italy, we don't have it here. Never even heard about it! Is
it Digital? Modulation CODFM? what is the bandwith? Here in Italy we have
DAB... do you have that in the US?

We don't have DAB because the National Association of Broadcasters
lobbied against it several years ago when they realized it would give
all stations in a market essentially the same coverage and possibly
allow new competitors into the game.

They do have DAB in Canada, but we have IBOC ("in-band, on-channel"),
or "HD Radio" as it has been recently rebranded. HD Radio allows a
station on the AM or FM bands to transmit a digital signal along with
the conventional analog signal. The catch is that the maximum bit
rate permitted by HD Radio is 96 kbps on the FM band and about 36 kbps
on AM. By comparison, DAB allows up to 256 kbps.


umar

I whole-heartedly agree with you on your findings "Umarc". It really has
nothing to offer the local **FM** listener. HOWEVER....in the Southern
California market it would kick ass on the "AM" market with a vengence.A lot
of the local AM outlets have sold out to the hispanic market because AM
radio sounds so bad for music.Considering how much better AM IBOC sounds
than analog, and the fact that the mexican government thinks it's cool to
fire up 10Khz away from US stations..IBOC is just what the renagade
beaner-blasters deserve.
I would like to see such stations like KNX,KFWB,KFI,KABC-AM (and some of the
San Diego stations) push the IBOC music service, the data services and
re-claim the 535-1710Khz band for use in the US of A.......Eddie

"umarc" wrote in message
...
I finally got to hear HD Radio (a.k.a. IBOC) on several Boston FM's
Saturday night (but not any AM's since it was night). My observations:

1. HD Radio does not sound appreciably better than FM.

2. On some of the stations there was a "gritty" quality to the sound
reminiscent of an MP3 Internet stream. To be fair, this could have
been the result of cascading HD Radio with an STL or digital audio
storage system employing something like MPEG or apt-X compression,
and not something inherent in HD Radio itself.

3. HD Radio does not appear to extend a station's coverage. On the
fringe of one station's coverage, where it could be heard in analog
FM imperfectly, the HD Radio was generally not audible at all. We
estimated that the effective range of the HD Radio signal is 90 to
95 percent of that of the analog FM.

4. The Kenwood receiver seems to mute in digital mode if there is
another signal on an adjacent channel.

5. It also mutes in the presence of nearby FM transmitter sites.

6. In analog mode, the digital sidebands of a station running HD
Radio can be heard as white noise. It is not yet possible to
guess how much interference they may cause because only a few
stations are running HD Radio yet.

7. The scrolling text display some stations were running may be a
considerable distraction to drivers.

After hearing some glowing reviews, I was prepared to hear something
approaching the sound of a CD and to want to push to put it on
our stations. Instead, my friends and I were asking ourselves why
anyone would want to pay $75,000 for it.

However, I am still reserving judgment. One night of listening on
one radio isn't enough; I want to hear it on several different
radios on a wider variety of stations, under different reception
scenarios. I'm particularly interested in the effect of adjacent-channel
interference.


umar

Mario dei Pintarei wrote:
Hi,
How does HD radio work? I'm an equipment designer (remote control
equipment) from Italy, we don't have it here. Never even heard about it! Is
it Digital? Modulation CODFM? what is the bandwith? Here in Italy we have
DAB... do you have that in the US?

I guess you could say "HD Radio" is the DAB system in the United States.
It is (very!) technically incompatible with the Eureka DAB system used
in Europe. http://www.ibiquity.com .

HD Radio is also known as "IBOC" - "In Band, On Channel". It places
digital carriers in the outer edges of the existing analog signal. (and
for MW IBOC, in the adjacent channels) It offers a "hybrid mode" in
which DAB and analog can be broadcast on the same frequency at the same
time.

All U.S. stations are currently allowed to begin DAB broadcasts at any
time, upon notifying the government. MW stations are only allowed to
broadcast DAB during the day, though nighttime authorization has been
requested. Very few stations are actually using DAB at this time - my
guess would be roughly 50 (most of them VHF/FM) throughout the country.

It is (IMHO) specifically designed to maintain the relative coverage
areas of different stations. (unlike, for example, the Eureka DAB in
Canada where all Montreal DAB stations have equal coverage, regardless
of the coverage of their associated analog stations)
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Eddie Haskel wrote:
I whole-heartedly agree with you on your findings "Umarc". It really has
nothing to offer the local **FM** listener. HOWEVER....in the Southern
California market it would kick ass on the "AM" market with a vengence.A lot
of the local AM outlets have sold out to the hispanic market because AM
radio sounds so bad for music.Considering how much better AM IBOC sounds
than analog, and the fact that the mexican government thinks it's cool to
fire up 10Khz away from US stations..IBOC is just what the renagade
beaner-blasters deserve.

My limited experience with AM IBOC is that it seems to sound worse than
the better quality AM analogue signals, and of course it makes it impossible
to put out a wideband analogue signal. It's also going to be much more
subject to adjacent channel interference from Mexico.

I wish I could say IBOC would be the saviour of AM, because AM certainly
could use one. I could at least believe IBOC will result in better quality
sound for the average listener on a cheap car radio listening in the daytime,
and you can argue that this is where the profit is.

I would like to see such stations like KNX,KFWB,KFI,KABC-AM (and some of the
San Diego stations) push the IBOC music service, the data services and
re-claim the 535-1710Khz band for use in the US of A.......Eddie

I'd be interested to see them try. And I will say that stations that try
IBOC are forced to clean up their antenna system and deal with group delay
problems, which will certainly benefit them if they should decide to move
back to wideband analogue operation.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 21 Mar 2004 06:01:53 GMT, "David Eduardo"
wrote:

Actually, there are fewer Spanish AMs than there have ever been in the last
20 years. Only 1020, 1330, 830 and a simulcast of 1330 on 1220 are Spanish.
Gone are 1430, 1580, 1480, 1090, 1540, 900 and several others that were
intermittently Spanish (like 1500, 1510, 670, 1190, etc.)

Oddly enough, some of these ended up doing (or will end up doing)
English-language talk or sports:

1580 - KBLA/Santa Monica, the L.A. affiliate of the new "Air America"
liberal radio network
1540 - KMPC, the Sporting News Radio O&O now sporting the historic 710
calls
1090 - XEPRS out of Baja California, now doing English-language sports
talk aimed at San Diego as "The Mighty 1090" (after the move of 690
Tijuana to a simulcast of KXTA/1150).

Mike

On 21 Mar 2004 06:01:55 GMT, (Scott Dorsey) wrote:

I wish I could say IBOC would be the saviour of AM, because AM certainly
could use one. I could at least believe IBOC will result in better quality
sound for the average listener on a cheap car radio listening in the daytime,
and you can argue that this is where the profit is.

Unfortunately, in my observation, IBOC degrades the analog signal
noticeably, even on a narrowband car radio.. The problem with AM IBOC
is not only the quality of the digital sound (yes, I know, there's
supposed to be a new codec that's better, but I've never heard AM IBOC
that sounded anything but terrible). It also degrades the listening
experience for everyone listening in analog, which for the foreseeable
future means everyone, period.

There is also a serious adjacent-channel interference problem which
does affect stations outside the coverage area of an AM station
transmitting IBOC. That is why it is not permitted at night, but the
problem also exists with daytime operation.


I would like to see such stations like KNX,KFWB,KFI,KABC-AM (and some of the
San Diego stations) push the IBOC music service, the data services and
re-claim the 535-1710Khz band for use in the US of A.......Eddie

IBOC may be a step to eliminating AM as an aural service, with the
allocations eventually used only for datacasting. Whether or not that
is the plan, it is the likely result. IMHO, IBOC will assure the end
of AM radio as we know it. Why anyone in the broadcasting industry
supports it as the "savior of AM" is utterly beyond my comprehension.
I find every argument advanced for it to be fallacious. If this is
what's supposed to save AM, then AM can't, and maybe shouldn't, be
saved.

Mark Howell

Mark Howell had written:
|
| IBOC may be a step to eliminating AM as an aural service, with the
| allocations eventually used only for datacasting. Whether or not that
| is the plan, it is the likely result. IMHO, IBOC will assure the end
| of AM radio as we know it. Why anyone in the broadcasting industry
| supports it as the "savior of AM" is utterly beyond my comprehension.
| I find every argument advanced for it to be fallacious. If this is
| what's supposed to save AM, then AM can't, and maybe shouldn't, be
| saved.
|
I would think that the "savior of AM" would be to provide
programming that people would want to listen to and that can be
received well in most of one's home market.

But aside from that, the FCC needs to do a little "birth control" --
or, more precisely, "euthanasia" -- by deleting operations who
facilities are clearly too marginal to provide aural service to a
majority of any given station's market area. The FCC, obviously,
would rather not crack this particular nut -- it's easier to focus
on boobies than it is on nuts-and-bolts infrastructure -- and has
backed off the few cases where it has tried to reduce interference
on the dial: for example, how many stations that "moved" to the
expanded band actually have given up their previous facilities? Not many.

--
"You're about to see a great sunset if you're in the right place."
-- KCBS morning traffic anchor, 6.58 am, February 9, 2004

"Mark Roberts" wrote in message
...
Mark Howell had written:
|
| IBOC may be a step to eliminating AM as an aural service, with the
| allocations eventually used only for datacasting. Whether or not that
| is the plan, it is the likely result. IMHO, IBOC will assure the end
| of AM radio as we know it. Why anyone in the broadcasting industry
| supports it as the "savior of AM" is utterly beyond my comprehension.
| I find every argument advanced for it to be fallacious. If this is
| what's supposed to save AM, then AM can't, and maybe shouldn't, be
| saved.

AM-Stereo, a previous savior, didn't kill AM, so now we have IBOC.

I would think that the "savior of AM" would be to provide
programming that people would want to listen to and that can be
received well in most of one's home market.

But aside from that, the FCC needs to do a little "birth control" --
or, more precisely, "euthanasia" -- by deleting operations who
facilities are clearly too marginal to provide aural service to a
majority of any given station's market area. The FCC, obviously,
would rather not crack this particular nut -- it's easier to focus
on boobies than it is on nuts-and-bolts infrastructure -- and has
backed off the few cases where it has tried to reduce interference
on the dial: for example, how many stations that "moved" to the
expanded band actually have given up their previous facilities? Not many.

No, the FCC has a better solution - the recently-closed window which
gathered over 1500 applications for new stations and major changes.

I recall years ago there was an effort to make it easier to buy and turn off
stations. The dreamers said that this would drive up the price of
stations - making them out of reach of new minority owners. The "big boys"
quickly figured that (already owning the big stations) they'd rather split
the ad pie with lots of struggling little stations that didn't have enough
ad income to compete, rather than a smaller number of stations each of which
got enough of the pie to be "dangerous". So the big station owners sided
with the dreamers and we have more and more uneconomic stations interfering
with each other.

I know of one x-band station that gave up its old channel. Since they also
have FM I wonder how long before they turn in the x-band license. Maybe the
PC in the closet which runs the AM doesn't cost enough to matter. Going
from 3 towers to one must save money.