Just a FYI, they turn the IBOC off at night, which is when most people
DX. However, I understand your concern. IBOC will probably fail.


wavetrapper wrote:
Pure speculation on my part. There probably was profit in it but not
huge. That may have been a very labor intenstive product to build.

Hard to get materials is one factor. Also, the crowd of MW DX'ers gets
smaller and smaller with each passing year. Not to mention the
forthcoming destruction of the MW DX hobby courtesy of IBOC/digital
radio (thanks to the built in adjecent channel hash interference).

The cumulative effect of all of that may have made it more trouble than
it was worth and there isn't much in the way of "future growth."

IBOC is not authorized currently for night use. It is ok to turn it on
at sunrise and have it run til sunset, I believe. Sunrise and sunset
are the two prime DX times on MW.

The broadcasters want it at night I think - which mean the FCC will
allow it eventually. They have to pretend to go through an
evaluation/consideration period first.

I can't see it succeeding on MW. Perhaps FM. I hope it does die a
quick death on MW.

wavetrapper wrote:

IBOC is not authorized currently for night use. It is ok to turn it on
at sunrise and have it run til sunset, I believe. Sunrise and sunset
are the two prime DX times on MW.

The broadcasters want it at night I think - which mean the FCC will
allow it eventually. They have to pretend to go through an
evaluation/consideration period first.

I can't see it succeeding on MW. Perhaps FM. I hope it does die a
quick death on MW.

Just like DRM.

DRM = QRM

dxAce
Michigan
USA

I actually have my Kiwa Air-Core Loop (bought years ago when they were
actually still being made) connected to my Yamaha RX-V4600 Home
Theatre receiver which happens to be able to tune AM IBOC. It
actually has a pretty good AM section. There are 3 local Detroit AM
stations transmitting IBOC during the daylight hours. Two of them
actually sound pretty good, the other one doesn't quite have their
IBOC encoding working all that well and has lots of digital artifacts.

The big problem, which kind of defeats the whole purpose is that, even
with the help of the Kiwa Loop, AM IBOC cannot be received in "IBOC
Mode" except for extremely strong local stations. Thus, even if I
want to listen to "clear channel" digital stations at sunset or
sunrise from other cities, the IBOC mode doesn't have enough digital
signal to "latch on" to the digital broadcast. Thus, all the DX IBOC
listener gets is a noisier, inferior AM DX signal, much worse sounding
than it would have been without IBOC. I've tried tuning WBZ in Boston
(an IBOC station) at sunrise, since they turn on their IBOC earlier
than in Detroit (we're on the western edge of the Eastern Time Zone).
They have an excellent analogue signal, but there's no hint of any
detection of their IBOC signal.

I also have DRM capabilities (a TenTec RX-350 receiver and computer
sound card based software). As DXAce reports, the QRN from DRM
transmissions to adjacent stations is JUST AS BAD OR WORSE than IBOC.
However, since DRM doesn't share "bandwidth" with an analogue signal
(as IBOC does), the sound quality of the received broadcasts are
vastly superior -- truly FM table radio comparable. In addition, DRM
is receivable over DX skywave conditions. I enjoy broadcasts from
Radio Luxembourg in the early morning hours in true high fidelity
stereo sound. DRM also allows vastly superior coverage with lower
transmitter power. Listening to the late-afternoon DRM transmission
of Radio Nederland from Bonaire with 5 kW, I get no dropouts and
excellent audio quality.

I doubt that shortwave broadcasting has much of a future, even with
DRM. Antenna real-estate is just too expensive and environmental laws
are stricter. However, those who complain about the QRN from DRM
broadcasts should consider that all forms of digital transmission
(RTTY, the Russian Woodpecker etc etc) produce horrible levels of
interference, and DRM is really no worse.

Fred E.
N8UC -- Detroit



wavetrapper wrote:

IBOC is not authorized currently for night use. It is ok to turn it on
at sunrise and have it run til sunset, I believe. Sunrise and sunset
are the two prime DX times on MW.

Byung Myung Sying wrote:

I actually have my Kiwa Air-Core Loop (bought years ago when they were
actually still being made) connected to my Yamaha RX-V4600 Home
Theatre receiver which happens to be able to tune AM IBOC. It
actually has a pretty good AM section. There are 3 local Detroit AM
stations transmitting IBOC during the daylight hours. Two of them
actually sound pretty good, the other one doesn't quite have their
IBOC encoding working all that well and has lots of digital artifacts.

The big problem, which kind of defeats the whole purpose is that, even
with the help of the Kiwa Loop, AM IBOC cannot be received in "IBOC
Mode" except for extremely strong local stations. Thus, even if I
want to listen to "clear channel" digital stations at sunset or
sunrise from other cities, the IBOC mode doesn't have enough digital
signal to "latch on" to the digital broadcast. Thus, all the DX IBOC
listener gets is a noisier, inferior AM DX signal, much worse sounding
than it would have been without IBOC. I've tried tuning WBZ in Boston
(an IBOC station) at sunrise, since they turn on their IBOC earlier
than in Detroit (we're on the western edge of the Eastern Time Zone).
They have an excellent analogue signal, but there's no hint of any
detection of their IBOC signal.

I also have DRM capabilities (a TenTec RX-350 receiver and computer
sound card based software). As DXAce reports, the QRN from DRM
transmissions to adjacent stations is JUST AS BAD OR WORSE than IBOC.
However, since DRM doesn't share "bandwidth" with an analogue signal
(as IBOC does), the sound quality of the received broadcasts are
vastly superior -- truly FM table radio comparable. In addition, DRM
is receivable over DX skywave conditions. I enjoy broadcasts from
Radio Luxembourg in the early morning hours in true high fidelity
stereo sound. DRM also allows vastly superior coverage with lower
transmitter power. Listening to the late-afternoon DRM transmission
of Radio Nederland from Bonaire with 5 kW, I get no dropouts and
excellent audio quality.

I doubt that shortwave broadcasting has much of a future, even with
DRM. Antenna real-estate is just too expensive and environmental laws
are stricter. However, those who complain about the QRN from DRM
broadcasts should consider that all forms of digital transmission
(RTTY, the Russian Woodpecker etc etc) produce horrible levels of
interference, and DRM is really no worse.

Well it certainly would be nice if the QRM (DRM) would migrate to a nice little
band of their own instead of QRMing everything else with their excessive
bandwidth.

DRM = QRM

Die DRM, die.

Oh, by the way, I recall folks saying that SWBC was dying 40 years ago.

Guess what? It ain't happened yet.

dxAce
Michigan
USA

I forget the Great City of Detroit Radio Station Call Sign/Lettes,but no
problem at all (WJR?) for me to pick up Detroit at night time.
cuhulin

Just a guess, but is the bandwidth big enough with the Kiwa? I'm
guessing you need 40Khz BW.

IBOC should work with a wellbrook, since they are untuned.

Byung Myung Sying wrote:
I actually have my Kiwa Air-Core Loop (bought years ago when they were
actually still being made) connected to my Yamaha RX-V4600 Home
Theatre receiver which happens to be able to tune AM IBOC. It
actually has a pretty good AM section. There are 3 local Detroit AM
stations transmitting IBOC during the daylight hours. Two of them
actually sound pretty good, the other one doesn't quite have their
IBOC encoding working all that well and has lots of digital artifacts.

The big problem, which kind of defeats the whole purpose is that, even
with the help of the Kiwa Loop, AM IBOC cannot be received in "IBOC
Mode" except for extremely strong local stations. Thus, even if I
want to listen to "clear channel" digital stations at sunset or
sunrise from other cities, the IBOC mode doesn't have enough digital
signal to "latch on" to the digital broadcast. Thus, all the DX IBOC
listener gets is a noisier, inferior AM DX signal, much worse sounding
than it would have been without IBOC. I've tried tuning WBZ in Boston
(an IBOC station) at sunrise, since they turn on their IBOC earlier
than in Detroit (we're on the western edge of the Eastern Time Zone).
They have an excellent analogue signal, but there's no hint of any
detection of their IBOC signal.

I also have DRM capabilities (a TenTec RX-350 receiver and computer
sound card based software). As DXAce reports, the QRN from DRM
transmissions to adjacent stations is JUST AS BAD OR WORSE than IBOC.
However, since DRM doesn't share "bandwidth" with an analogue signal
(as IBOC does), the sound quality of the received broadcasts are
vastly superior -- truly FM table radio comparable. In addition, DRM
is receivable over DX skywave conditions. I enjoy broadcasts from
Radio Luxembourg in the early morning hours in true high fidelity
stereo sound. DRM also allows vastly superior coverage with lower
transmitter power. Listening to the late-afternoon DRM transmission
of Radio Nederland from Bonaire with 5 kW, I get no dropouts and
excellent audio quality.

I doubt that shortwave broadcasting has much of a future, even with
DRM. Antenna real-estate is just too expensive and environmental laws
are stricter. However, those who complain about the QRN from DRM
broadcasts should consider that all forms of digital transmission
(RTTY, the Russian Woodpecker etc etc) produce horrible levels of
interference, and DRM is really no worse.

Fred E.
N8UC -- Detroit



wavetrapper wrote:

IBOC is not authorized currently for night use. It is ok to turn it on
at sunrise and have it run til sunset, I believe. Sunrise and sunset
are the two prime DX times on MW.