Coverage "loss" due to IBOC

[Len14043]

I read some of Bruce Carter's posts and was trying to make sense out of some of his claims that the analog coverage could be cut if half. I can see his point if you look at it through the eyes of a DXer. I mentioned in an earlier post that it was possible to listen to 102.9 from Springfield in Cincinnati before the 102.7 in Cincinnati implemented IBOC. For a dxer, if the 102.9 from Springfield can't be heard in the 10-15 mile fringe area, when it was previously possible, that "could" translate into a loss of coverage of 50% in terms of area. Conversly, a casual listener tuned to 102.9 while driving from Springfield towards Cincinnati would likely change the station when the Cincinnati station on 102.7 started to interfere with 102.9-even if 102.7 wasn't running IBOC. To the casual listener, the "interference" created by IBOC wouldn't be noticeable. The bottom line is: The loss of coverage is real from the perspective of a DXer, but is likely not a factor for the casual listener.

 

[k9ez]

> I read some of Bruce Carter's posts and was trying to make
> sense out of some of his claims that the analog coverage
> could be cut if half. I can see his point if you look at it
> through the eyes of a DXer. I mentioned in an earlier post
> that it was possible to listen to 102.9 from Springfield in
> Cincinnati before the 102.7 in Cincinnati implemented IBOC.
> For a dxer, if the 102.9 from Springfield can't be heard in
> the 10-15 mile fringe area, when it was previously possible,
> that "could" translate into a loss of coverage of 50% in
> terms of area. Conversly, a casual listener tuned to 102.9
> while driving from Springfield towards Cincinnati would
> likely change the station when the Cincinnati station on
> 102.7 started to interfere with 102.9-even if 102.7 wasn't
> running IBOC. To the casual listener, the "interference"
> created by IBOC wouldn't be noticeable. The bottom line is:
> The loss of coverage is real from the perspective of a DXer,
> but is likely not a factor for the casual listener.
>


I am a DXer as well. Please see my post about HD and adjacent signals. That might help clear some things up.

Bruce was suggesting that when you put HD on a station, THAT station would lose major signal. If you know how the system operates you will see that is just not possible.

 

[_Jim]

>
>
> I am a DXer as well. Please see my post about HD and
> adjacent signals. That might help clear some things up.
>
> Bruce was suggesting that when you put HD on a station, THAT
> station would lose major signal. If you know how the system
> operates you will see that is just not possible.
>

Wow ... I wonder what the propagation prediction coverage
including 1st (affected directly by the IBOC Hybrid sidebands)
and 2nd adjacent (due more to wide receiver IF filters) signals
shows during for run of a full-up metro coverage prediction plot,
and then blending that over into the 'coverage' plots for what
suburban listeners would experience; I've got to believe that a
whole lot of weaker, fringe and rim shot stations are going to
be 'covered over' in the Hybrid IBOC scenario on FM.

This is also going to look really horrid the first time a
tropo event (tropospheric ducting propation event) is seen;
no 'coverage' except for a 15 (maybe 20) mile radius circle
from the xmit site.