Re: [IRCA] All-Digital AM Co-Channel Lab Test Results Unveiled

[Russ Edmunds <wb2bjh@xxxxxxxxx>]

Bottom line, this is, after all, the NAB, and their mantra is "More, more
more stations". I would expect their rsults to understate the potential
issues.

That said, a straight up digital signal would occupy the center of the main
channel - where today's analog signal is. And the digital signal should
occupy less bandwidth by itself and a typical analog signal. The IBOC
hybrid mode has the analog signal at center and the two hybrid digital
signals on either side. Thus the combined IBOC signal occupies
substantially more bandwidth than a single digital signal. That's why Chuck
said ( or one reason why ) it wasn't comparable. But that also doesn't
predict much else.

Russ Edmunds
15 mi NW Phila
Grid FN20id
<wb2bjh@xxxxxxxxx>

AM: Modified Sony ICF2010's (2) barefoot w/whip
FM: Yamaha T-80 & T-85, each w/ Conrad RDS Decoder;
Onkyo T-450RDS; Tecsun PL-310 ( 2);
modified Sony ICF2010 w/APS9B @ 15';
Grundig G8 w/whip; modified Sony ICF2010 w/whip


On Fri, Apr 22, 2016 at 12:15 PM, Nick Hall-Patch <nhp@xxxxxxxx> wrote:

> It's quite easy to correlate Chuck.  Just add ignorance and stir.  I don't
> believe they actually said anything much about the digital signal, so
> assumption of all digital IBOC can reasonably be added to that mix.  (other
> details about demodulation of the analog signal are also missing)
>
> Audio examples would be nice, and might help to convince the doubters.
>
>
> http://www.radiomagonline.com/deep-dig/0005/broadcast-engineering-conference-radio-technology-forum-sessions/37600
> offers descriptions of the conference sessions, but I haven't been able to
> quickly track down any more detailed results than what Dennis linked to.
>
> http://diymedia.net/old/stuff/AM_IBOC_Test.pdf  has a nice graphic on the
> first page which I assume is what Chuck is alluding to in terms of the
> difference  between present IBOC and all-digital IBOC.   Is that the case
> Chuck?  If so, perhaps you could suggest a listening test that could be
> done with today's systems (thereby saving me the trouble of doing it
> incorrectly)?   Those secondary OFDM subcarriers already sound pretty nasty
> on KRKO's signal this morning, and they would be stronger in the digital
> only version.
>
> best wishes,
>
> Nick
>
>
>
>
>
>
> At 05:03 22-04-16, you wrote:
>
>> ...
>>
>> I don't see how you can correlate hybrid IBOC to all digital IBOC. What
>> you hear with KRKO/KAST is different from what you will hear
>> with all digital as the power spectrum and subcarrier levels are vastly
>> different.
>>
>> Chuck
>> ________________________________________
>> From: IRCA <irca-bounces@xxxxxxxxxxxxxxxx> on behalf of Nick Hall-Patch <
>> nhp@xxxxxxxx>
>> Sent: Friday, April 22, 2016 4:51 AM
>> To: Mailing list for the International Radio Club of America
>> Subject: Re: [IRCA] All-Digital AM Co-Channel Lab Test Results Unveiled
>>
>> I presume "D/U" abbreviation in this piece refers to "desired /
>> undesired"?
>>
>> I wonder if someone recorded audio from those tests, rather than just
>> tossing dB's around?   I have a recording of KAST-1370 from this
>> morning that says otherwise, with KRKO-1380 IBOC sidebands about 25dB
>> down and....welll, KAST is readable, but I wouldn't say it's lacking
>> interference.   The noise becomes really dominant if KAST is less
>> than ~15dB above the IBOC level.
>>
>> best wishes,
>>
>> Nick
>>
>>
>>
>>
>> At 21:05 21-04-16, you wrote:
>> >http://www.radioworld.com/article/all-digital-am-co-channel-lab-tes
>> t-results-unveiled/278670
>> >
>> >Sent from my iPad
>> >_______________________________________________
>> >IRCA mailing list
>> >IRCA@xxxxxxxxxxxxxxxx
>> >http://montreal.kotalampi.com/mailman/listinfo/irca
>> >
>> >Be sure to register now for the Joint DX Convention
>> >Kansas City, September 9 to 11.  Hotel space is filling up.
>> >Registration info:
>> >http://www.nrcdxas.org
>> >
>> >
>> >Opinions expressed in messages on this mailing list are those of the
>> >original contributors and do not necessarily reflect the opinion of
>> >the IRCA, its editors, publishing staff, or officers
>> >
>> >For more information: http://www.ircaonline.org
>> >
>> >To Post a message: irca@xxxxxxxxxxxxxxxx
>>
>>
>> _______________________________________________
>> IRCA mailing list
>> IRCA@xxxxxxxxxxxxxxxx
>> http://montreal.kotalampi.com/mailman/listinfo/irca
>>
>> Be sure to register now for the Joint DX Convention
>> Kansas City, September 9 to 11.  Hotel space is filling up.
>> Registration info:
>> http://www.nrcdxas.org
>>
>>
>> Opinions expressed in messages on this mailing list are those of the
>> original contributors and do not necessarily reflect the opinion of the
>> IRCA, its editors, publishing staff, or officers
>>
>> For more information: http://www.ircaonline.org
>>
>> To Post a message: irca@xxxxxxxxxxxxxxxx
>>
>> _______________________________________________
>> IRCA mailing list
>> IRCA@xxxxxxxxxxxxxxxx
>> http://montreal.kotalampi.com/mailman/listinfo/irca
>>
>> Be sure to register now for the Joint DX Convention
>> Kansas City, September 9 to 11.  Hotel space is filling up.
>> Registration info:
>> http://www.nrcdxas.org
>>
>>
>> Opinions expressed in messages on this mailing list are those of the
>> original contributors and do not necessarily reflect the opinion of the
>> IRCA, its editors, publishing staff, or officers
>>
>> For more information: http://www.ircaonline.org
>>
>> To Post a message: irca@xxxxxxxxxxxxxxxx
>>
>
>
> _______________________________________________
> IRCA mailing list
> IRCA@xxxxxxxxxxxxxxxx
> http://montreal.kotalampi.com/mailman/listinfo/irca
>
> Be sure to register now for the Joint DX Convention
> Kansas City, September 9 to 11.  Hotel space is filling up.
> Registration info:
> http://www.nrcdxas.org
>
>
> Opinions expressed in messages on this mailing list are those of the
> original contributors and do not necessarily reflect the opinion of the
> IRCA, its editors, publishing staff, or officers
>
> For more information: http://www.ircaonline.org
>
> To Post a message: irca@xxxxxxxxxxxxxxxx
>
>
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Be sure to register now for the Joint DX Convention
Kansas City, September 9 to 11.  Hotel space is filling up.
Registration info:
http://www.nrcdxas.org


Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx