In article ,
Richard Evans wrote:

DigitalRadioScams wrote:

The whole IBOC system was puposely designed to jam the smaller
adjacent-cheenl stations of the dial.

So is that why it's so spectrally inefficient?
To use up more bandwidth, hence produce more jamming.

The idea was to ultimately retire analog FM entirely, thus enabling
iBiquity to capture a royalty on every bit of material on the FM band.
iBiquity understated the amount of IBOC signal necessary to achieve
"equivalent" coverage with the stations' FM signals so that it could get
its foot in the door.

When it became apparent that -20db was inadequate (even though there was
still major interference with analog signals), they lobbied for -10db.
That was an "oops" of an order of magnitude. They got -14db instead, but
the deleterious effects on analog FM at that level remains to be seen,
since most stations have yet to take advantage of it.

--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last

On 9/5/10 7:40 PM, John Higdon wrote:
iBiquity understated the amount of IBOC signal necessary to achieve
"equivalent" coverage with the stations' FM signals so that it could get
its foot in the door.

I think we have seem the same thing for DAB and DRM. The low powers are
just sales talk.

gr, hwh

John Higdon wrote:


Don't worry...it isn't a "book". It is one of Radio World's usual
half-assed articles that pretends to be technical. Believe me, real
radio engineers don't learn from Radio World.


And I don't need any book or article to know that 2 different radio
signals on the same frequency, is not a good idea.

hwh wrote:


I think we have seem the same thing for DAB and DRM. The low powers are
just sales talk.

Lower power would be fine, if DAB had better error correction.

Although there is one situation where low power DAB works well, that is
in the middle of an SFN with signals coming in from several different
directions. This isn't much use however in the outer areas of a local
multiplex.

On 9/5/2010 8:31 AM, Richard Evans wrote:
SMS wrote:


Here's a book that you can read to understand how IBOC works (I mean
if you actually want to understand it).

"http://www.radioworld.com/article/8410".

So I have to buy a book, and find time to read through it, to find out
about something I'm not especially interested in. Thanks for the link,
but I think I'll pass on this one.

No, you don't have to do anything. If you were interested in
understanding the technology of IBOC rather than making uninformed
comments about it, it would be a wise thing to do. But apparently you're
content to talk about things you "know" that aren't actually true.
Whatever lights your board.

On 9/5/2010 9:50 AM, Kevin Alfred Strom wrote:

The big boys pushed IBOC because they wanted to do whatever they could
to _prevent_ the creation of a new all-digital band. They feared that
such a new band would level the playing field so the small broadcaster
would have just as good coverage as they did. That was an intolerable
and frightening idea to them.

That's part of it, but they also did not want to have to pay for the
additional spectrum on a new band.

For all the misinformation that our favorite troll promulgates here, the
fact is that FM IBOC works very well indeed. There have been very few
complaints about interference, and the few complaints that there were,
were found to have no merit because the interference occurred outside
the protected contour (though this was before the power increase was
granted).

I'm sure our favorite troll is well aware of what this law firm is
doing. There is no lawsuit, and there is unlikely to be one. They are
trying to see if they can wrangle some kind of money from BMW and other
automakers.

SMS wrote:


No, you don't have to do anything. If you were interested in
understanding the technology of IBOC rather than making uninformed
comments about it, it would be a wise thing to do. But apparently you're
content to talk about things you "know" that aren't actually true.
Whatever lights your board.

I know as much as I need to know.

Spectrally in efficient.
Causes interference to other services.
Is used at bit rates so low that sound quality can't possibly be
anything better than horrible.

In article ,
SMS wrote:

For all the misinformation that our favorite troll promulgates here, the
fact is that FM IBOC works very well indeed. There have been very few
complaints about interference, and the few complaints that there were,
were found to have no merit because the interference occurred outside
the protected contour (though this was before the power increase was
granted).

Do you feel that if you repeat this often enough it will become true? I
have repeatedly told you that KKDV, Walnut Creek, whose primary 60dbu
contour encompasses Berkeley and part of Oakland is unlistenable due to
interference from the IBOC signal from KSJO, San Jose. I have
documentation an inch thick on this issue. I have mentioned it here a
dozen times. Your response is to wait a few weeks saying nothing, and
then repeat your canned, unsupported nonsense above.

Trolls are one thing; broadcast engineers such as Dave Barnett, Patty
Winter, and others including myself are real people with real experience
with regard to IBOC. How glib of you to include all of us with the
trolls.

I'm sure our favorite troll is well aware of what this law firm is
doing. There is no lawsuit, and there is unlikely to be one. They are
trying to see if they can wrangle some kind of money from BMW and other
automakers.

I have most of the trolls killfiled, so I wouldn't know about whom you
are speaking. But to dismiss real, working radio engineers (who have
absolutely no vested interest in the failure of IBOC, and even have much
to gain by its success) claiming incompetence or devious intent is
intellectually dishonest and reflects more upon yourself than on us.

Please do let us know when you are ready to address the issues we have
repeatedly brought up regarding IBOC in some worthy manner rather than
waiting a few weeks and then dismissing it in general with your usual
unsupported generalization.

--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last

In article ,
SMS wrote:

No, you don't have to do anything. If you were interested in
understanding the technology of IBOC rather than making uninformed
comments about it, it would be a wise thing to do. But apparently you're
content to talk about things you "know" that aren't actually true.
Whatever lights your board.

I would suggest asking a real, working radio technician how IBOC works
rather than reading Radio World, well known INSIDE the industry as being
pretty much a rag.

--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last

In article ,
Richard Evans wrote:

Spectrally in efficient.
Causes interference to other services.
Is used at bit rates so low that sound quality can't possibly be
anything better than horrible.

Pretty good summary. I created a long version several years ago with
numbers, graphs, and spectrum analyzer photos. I'll see if I can dig
that up.

--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last