Frank Dresser wrote:
"Ruud Poeze" wrote in message
But with DRM you loose your analogue audience, since it is digital only.
So for a long period of time you need 2 frequencies and 2 transmitters
at least per channel! Impossible on AM, and SW broadcasters will have a
I can't see why any US MW broadcaster would have any interest in DRM, even
if the FCC allows it.

On the other hand, we do now have "duopoly" in the U.S. - it's now legal
for the same company to own more than one AM station in the same city.

WLAC could, for example, buy WAMB-1160. Convert WAMB to DRM, and use it
to carry the same program (but in digital mode) as WLAC. Once (if!) the
majority of listeners have DRM radios, they could swap stations for a
few years. (converting WLAC to DRM and WAMB back to analog) When the
number of analog radios in use becomes negligible, either shut off WAMB,
sell it to someone else, or start a second DRM station.

Most group owners are still far enough short of the limit for the number
of AM stations they're permitted to own in most major markets, and there
are generally enough "also-ran" small AM stations available to buy. The
coverage of the DRM stations would be less than that of the existing
analog outlets, but if the IBOC adjacent-channel interference from other
stations isn't there then the actual coverage with DRM might well be
*better*.

Of course, the *right* answer (for the listener, not for the DXer!) is
Eureka on VHF/UHF.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

"Doug Smith W9WI" wrote in message
...

On the other hand, we do now have "duopoly" in the U.S. - it's now legal
for the same company to own more than one AM station in the same city.

WLAC could, for example, buy WAMB-1160. Convert WAMB to DRM, and use it
to carry the same program (but in digital mode) as WLAC. Once (if!) the
majority of listeners have DRM radios, they could swap stations for a
few years. (converting WLAC to DRM and WAMB back to analog) When the
number of analog radios in use becomes negligible, either shut off WAMB,
sell it to someone else, or start a second DRM station.

Most group owners are still far enough short of the limit for the number
of AM stations they're permitted to own in most major markets, and there
are generally enough "also-ran" small AM stations available to buy. The
coverage of the DRM stations would be less than that of the existing
analog outlets, but if the IBOC adjacent-channel interference from other
stations isn't there then the actual coverage with DRM might well be
*better*.

Yes, but if the second station doesn't increase revenues by increasing
audience, the money is wasted. Not that broadcasters haven't wasted money
like that before, they used to simulcast their AM programming on FM. But
the FCC didn't like simulcasting, and pretty much stopped it.

AM IBOC has been around for a year or two, and it's still something of a
novelty. It doesn't seem to be taking off as quickly as AM Stereo, and
there aren't many receivers available, yet.

I also don't know if there's much of a market for digital radios which
receive the same old stuff that any old cheap radio receives. Maybe if all
the radios were the same price, but IBOC hopes to make money on licensing
fees.

I don't know the bandwidth of full digital IBOC, but if the full digital
bandwidth is the same as DRM, it seems the IBOC has an advantage with the
transitional hybrid system.



Of course, the *right* answer (for the listener, not for the DXer!) is
Eureka on VHF/UHF.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com


If we ever manage how to figure out how to put satellites up reliably and
economically, the networks will probably put up high-power, non-subscription
direct broadcast satellites.


Frank Dresser

Frank Dresser wrote:
Yes, but if the second station doesn't increase revenues by increasing
audience, the money is wasted. Not that broadcasters haven't wasted money
like that before, they used to simulcast their AM programming on FM. But
the FCC didn't like simulcasting, and pretty much stopped it.

True, though then again is that different from IBOC? (admittedly IBOC
is probably cheaper, though again if IBOC is accomplished at the expense
of massive interference, will that really help the bottom line?)

AM IBOC has been around for a year or two, and it's still something of a
novelty. It doesn't seem to be taking off as quickly as AM Stereo, and
there aren't many receivers available, yet.

True.

I also don't know if there's much of a market for digital radios which
receive the same old stuff that any old cheap radio receives. Maybe if all
the radios were the same price, but IBOC hopes to make money on licensing
fees.

And again true.


--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

"Doug Smith W9WI" wrote in message
...
Frank Dresser wrote:
Yes, but if the second station doesn't increase revenues by increasing
audience, the money is wasted. Not that broadcasters haven't wasted
money
like that before, they used to simulcast their AM programming on FM.
But
the FCC didn't like simulcasting, and pretty much stopped it.

True, though then again is that different from IBOC?

That would depend on IBOC's costs. It's possible that Ibiquity is
subsidizing the early adopters.

Chicago's WIND is a curious case. They went to IBOC a couple of months ago.
I'd think a station like WIND would be just about the last station to adopt
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the low
end of the dial seems to be an engineering worst case scenerio. But they're
doing it, and they're doing it before there's any significant number of AM
IBOC receivers. I'm just guessing, but I think they wouldn't bother unless
they were getting some breaks on the deal from Ibiquity.


(admittedly IBOC
is probably cheaper, though again if IBOC is accomplished at the expense
of massive interference, will that really help the bottom line?)



There should be enough seperation between stations in any market to avoid
interference. The interference problem will happen in the fringe areas
where adjacent channels can also be received well. This doesn't seem to
bother the broadcasters. I think the National Association of Broadcasters
is lobbying to get the nighttime ban on IBOC removed.

Luckily for the radio hobbyist, AM IBOC doesn't seem to be gathering
momentum, for whatever reason. That's remarkable, given the number of
networks investing in Ibiquity:

http://www.ibiquity.com/about/invest_radio.htm

Frank Dresser

"Frank Dresser" schreef in bericht
...
Chicago's WIND is a curious case. They went to IBOC a couple of months
ago.
I'd think a station like WIND would be just about the last station to
adopt
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the low
end of the dial seems to be an engineering worst case scenerio.

I understood this has something to do with the Q-factor of the aerial, is
that correct?
You actually need a bad aerial for IBOC :-)

gr, hwh

"hwh" wrote in message
...

"Frank Dresser" schreef in bericht
...
Chicago's WIND is a curious case. They went to IBOC a couple of months
ago.
I'd think a station like WIND would be just about the last station to
adopt
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the
low
end of the dial seems to be an engineering worst case scenerio.

I understood this has something to do with the Q-factor of the aerial, is
that correct?
You actually need a bad aerial for IBOC :-)

gr, hwh



There are ways of broadbanding an AM tower. One way is to add longwire
antennas in parallel to the main tower, stood off by a couple feet or so. I
helped install such a system in Portland, Oregon a few years ago.

Brenda Ann Dyer wrote:
There are ways of broadbanding an AM tower. One way is to add longwire
antennas in parallel to the main tower, stood off by a couple feet or so. I
helped install such a system in Portland, Oregon a few years ago.

True, though in most cases I would think the narrowband problem is in
the matching network, (especially at highly-directional stations) not
the individual tower(s).
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

In article ,
"Brenda Ann Dyer" wrote:

"hwh" wrote in message
...

"Frank Dresser" schreef in bericht
...
Chicago's WIND is a curious case. They went to IBOC a couple of months
ago.
I'd think a station like WIND would be just about the last station to
adopt
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the
low
end of the dial seems to be an engineering worst case scenerio.

I understood this has something to do with the Q-factor of the aerial, is
that correct?
You actually need a bad aerial for IBOC :-)

gr, hwh



There are ways of broadbanding an AM tower. One way is to add longwire
antennas in parallel to the main tower, stood off by a couple feet or so. I
helped install such a system in Portland, Oregon a few years ago.

What you did in effect with the parallel wires was to increase the
diameter of the tower relative to its length, which will broaden its
response. The towers response curve will have a lower and broader
peak.

--
Telamon
Ventura, California

hwh wrote:
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the low
end of the dial seems to be an engineering worst case scenerio.

I understood this has something to do with the Q-factor of the aerial, is
that correct?
You actually need a bad aerial for IBOC :-)

G

though really, I would suggest a broadcasting antenna with a high Q
factor is *not* a good antenna... Either the matching network is poorly
designed, or the height of the antenna is such that the resulting
impedance is difficult to match with a reasonable network..
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Frank Dresser wrote:
That would depend on IBOC's costs. It's possible that Ibiquity is
subsidizing the early adopters.

I certainly wouldn't rule that out. A bit of "seed money" to get some
well-known examples on the air.

That won't bode well for eventual widespread adoption though. The big
stations they're starting with are the same ones with the ability to
raise the capital to pay full price. It's the little stations that will
have trouble paying for IBOC at subsidized prices, let alone full price.

Chicago's WIND is a curious case. They went to IBOC a couple of months ago.
I'd think a station like WIND would be just about the last station to adopt
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the low
end of the dial seems to be an engineering worst case scenerio. But they're
doing it, and they're doing it before there's any significant number of AM
IBOC receivers. I'm just guessing, but I think they wouldn't bother unless
they were getting some breaks on the deal from Ibiquity.

IIRC WIND is an Entravision-owned station. They seem to be an early
supporter. (several of their L.A. stations, for example, are using it)
But you could well be right that Ibiquity has given Entravision some
incentives...

WIND's directtional pattern is relatively "mild", I suspect there are
many arrays out there that will be a LOT harder to make work. WLMV-1480
in Madison, for example; when they were WISM they had bandwidth problems
with *analog*. [0]

There should be enough seperation between stations in any market to avoid
interference. The interference problem will happen in the fringe areas
where adjacent channels can also be received well.

Or from stations in different markets.

You don't have to get very far fringe before you find people whose only
nighttime AM service is secondary. At my location, WSM is the only
primary nighttime service. My educated guess is the number of people
who would receive *no* nighttime AM service is in the hundreds of
thousands. In the state of Tennessee alone.

It's true that "This doesn't seem to bother the broadcasters."
However, these hundreds of thousands of people have Congressmen who
certainly can bother the broadcastersgrin!

I think the National Association of Broadcasters
is lobbying to get the nighttime ban on IBOC removed.

Yes, there's an official proceeding open before the FCC on this subject.
(among others related to IBOC)

Luckily for the radio hobbyist, AM IBOC doesn't seem to be gathering
momentum, for whatever reason. That's remarkable, given the number of
networks investing in Ibiquity:

I do think it will go the way of AM stereo, and for many of the same
reasons.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

[0] The regular-band side of WTDY-1670, this one was supposed to go away
by now like most of the other X-band movers...