WBT's Digital Test - "Is There Hope For A Digital AM Band?"


Stephen H. Ponder <stephen_ponder@...>
 

Article from Radio Insight ...

http://radioinsight.com/blog/headlines/84743/is-there-hope-for-a-digital-am-band/

73 & Good DX,

Steve Ponder, N5WBI
Houston, TX
_____________________
Sent from my Kindle Fire HD 8.9


bbwrwy
 

I occasionally listen to the DRM digital broadcasts of Radio New Zealand International on the short wave band. Their signal is usually crystal clear here, but whenever the signal strength drops there is nothing to hear until the receiver is able to reacquire it again. At least with the parallel AM broadcast it's simply fades slightly. Also, nearby lightning strikes can disrupt the signal causing its loss along unpleasant popping noises. I see something similar with OTA DTV during thunderstorms. Having not heard a decoded AM IBOC broadcast, I can't say how it will sound. I'm sre there are still bugs to fix and can't imagine it being a tool for DX listening. And it requires wider bandwidth than present AM broadcasts.

So on we move into the chaotic digital future!

Richard.

Richard Allen,
near Perry OK USA.

--- In ultralightdx@..., "Stephen H. Ponder" <stephen_ponder@...> wrote:

Article from Radio Insight ...

http://radioinsight.com/blog/headlines/84743/is-there-hope-for-a-digital-am-band/

73 & Good DX,

Steve Ponder, N5WBI
Houston, TX
_____________________
Sent from my Kindle Fire HD 8.9


Bruce Conti
 

On Wed, Aug 21, 2013 at 11:39 PM, RichardA <richarda@...> wrote:
...and it requires wider bandwidth than present AM broadcasts.

Unlike the hybrid analog/digital mode currently being used which extends to about +/-15 kHz from the center frequency, all-digital mode is contained within +/-10 kHz of the center frequency.  Currently the strongest digital sidebands of hybrid at +/-10 to 15 kHz from the center frequency are also at reduced power.  In all-digital mode, the digital signal will be more powerful.  So using hybrid as a gauge would be invalid for how bad all-digital might be.  Regardless, there just isn't enough bandwidth between channels for reliable digital on the AM broadcast band at night with all the adjacent channel skywave interference, in addition to co-channel interference and noise.  Can't envision all-digital being practical for 50 kW if nighttime coverage isn't any better than 15 miles, never mind the loss of coverage area for already anemic 5 kW and 1 kW signals.  I missed the 1110 WBT all-digital test, but my most distant hybrid digital reception is 261 miles with an intermittent 1210 WPHT at night.

--
Bruce Conti
B.A.Conti Photography www.baconti.com
¡BAMLog! www.bamlog.com


keith beesley
 

I can't imagine we'll ever see an all-digital AM band. Your average radio listener is not going to want to go out and buy a new radio, or a converter box, just to listen to radio. They would just switch to listening on a smart phone or tablet.


Just my $.02.


Keith Beesley

Seattle, WA USA


--- In ultralightdx@..., <contiba@...> wrote:

On Wed, Aug 21, 2013 at 11:39 PM, RichardA <richarda@...> wrote:
...and it requires wider bandwidth than present AM broadcasts.

Unlike the hybrid analog/digital mode currently being used which extends to about +/-15 kHz from the center frequency, all-digital mode is contained within +/-10 kHz of the center frequency.  Currently the strongest digital sidebands of hybrid at +/-10 to 15 kHz from the center frequency are also at reduced power.  In all-digital mode, the digital signal will be more powerful.  So using hybrid as a gauge would be invalid for how bad all-digital might be.  Regardless, there just isn't enough bandwidth between channels for reliable digital on the AM broadcast band at night with all the adjacent channel skywave interference, in addition to co-channel interference and noise.  Can't envision all-digital being practical for 50 kW if nighttime coverage isn't any better than 15 miles, never mind the loss of coverage area for already anemic 5 kW and 1 kW signals.  I missed the 1110 WBT all-digital test, but my most distant hybrid digital reception is 261 miles with an intermittent 1210 WPHT at night.

--
Bruce Conti
B.A.Conti Photography www.baconti.com
¡BAMLog! www.bamlog.com


bbwrwy
 

Keith:

Those were my thoughts as I typed my earlier comments. I'm not sure the youngsters of today know what a radio receiver is. They already carry around a smartphone or device capable of receiving thousands of radio stations. Why do they want to bother with tuning a digital radio receiver to hear the same thing?

Richard Allen,
near Perry OK USA.


Peter Laws
 

On Thu, Aug 22, 2013 at 12:18 PM, RichardA <richarda@...> wrote:
Keith:

Those were my thoughts as I typed my earlier comments. I'm not sure the youngsters of today know what a radio receiver is. They already carry around a smartphone or device capable of receiving thousands of radio stations. Why do they want to bother with tuning a digital radio receiver to hear the same thing?
Also, Get Off My Lawn! :-)

You're right, of course, and I'm not sure they would even bother with
something like iHeartradio because the same device has 2000 of their
favorite songs available whenever they want in whatever order they
want.

Most of them would be surprised to find out that their phones were
multi-band transceivers. My new Samsung ...

o transmits and receives WiFi on both 2.4 GHz and 5 GHz
o transmits and receives Bluetooth on 2.4 GHz (spread spectrum at that)
o transmits and receives on 6 different cellular bands ("world" phone)
o transmits and receives on 13.56 MHz(!) using the NFC protocol
o receives GPS *and* GLONASS signals

... and I would guess that less than 0.1% of the people that have them
know this. All they know is that it's "wireless". I didn't even know
how the near field stuff worked - I'll test it when I'm near my HF
transceiver. :-)

So with all that giving them anything they want (I can stream live
video or Netflix, after all), why would they even concern themselves
with AM or even FM radio?

I see dark days ahead for broadcasters, unfortunately, let alone for our hobby.

Oh - I actually just RTFA and see that the average age of an AM radio
listener is *already* 65. Bet it's only about 15-20 less for FM.


ferrite61 <dxrx@...>
 

Is there hope? Maybe your CATV provider will come to the rescue. Most internet radio stations are not relays of real radio stations... just a jukebox of pre-programmed listening based upon your likes. Quite manipulative in theory. Then again most young people cannot watch the video of a movie and listen to a baseball game simultaneously. They need focus on one OR the other.

Paul S. in CT

--- In ultralightdx@..., Peter Laws <plaws0@...> wrote:

On Thu, Aug 22, 2013 at 12:18 PM, RichardA <richarda@...> wrote:
Keith:

Those were my thoughts as I typed my earlier comments. I'm not sure the youngsters of today know what a radio receiver is. They already carry around a smartphone or device capable of receiving thousands of radio stations. Why do they want to bother with tuning a digital radio receiver to hear the same thing?
Also, Get Off My Lawn! :-)

You're right, of course, and I'm not sure they would even bother with
something like iHeartradio because the same device has 2000 of their
favorite songs available whenever they want in whatever order they
want.

Most of them would be surprised to find out that their phones were
multi-band transceivers. My new Samsung ...

o transmits and receives WiFi on both 2.4 GHz and 5 GHz
o transmits and receives Bluetooth on 2.4 GHz (spread spectrum at that)
o transmits and receives on 6 different cellular bands ("world" phone)
o transmits and receives on 13.56 MHz(!) using the NFC protocol
o receives GPS *and* GLONASS signals

... and I would guess that less than 0.1% of the people that have them
know this. All they know is that it's "wireless". I didn't even know
how the near field stuff worked - I'll test it when I'm near my HF
transceiver. :-)

So with all that giving them anything they want (I can stream live
video or Netflix, after all), why would they even concern themselves
with AM or even FM radio?

I see dark days ahead for broadcasters, unfortunately, let alone for our hobby.

Oh - I actually just RTFA and see that the average age of an AM radio
listener is *already* 65. Bet it's only about 15-20 less for FM.


Peter Laws
 

On Fri, Aug 23, 2013 at 12:06 AM, ferrite61 <dxrx@...> wrote:
Is there hope? Maybe your CATV provider will come to the rescue. Most internet radio stations are not relays of real radio stations... just a jukebox of pre-programmed listening based upon your likes. Quite manipulative in theory. Then again most young people cannot watch the video of a movie and listen to a baseball game simultaneously. They need focus on one OR the other.
That would be Pandora, which most of my younger friends (I work at a
university) seem to enjoy if not running a playlist of their own.
iPods have been around long enough that people may be beginning to
forget, and maybe dislike, the interruptions of "real radio".

As someone in this thread (or maybe in the comments of the story that
started this thread) said if a station really wants to be successful,
it needs a compelling product, and right now that's in very short
supply.


--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!