Well, maybe my experience is unique, but my recent  observations about WBBM 
A M were made during the day-time, which really illustrated the problem for 
me, more than I expected.

Tom Behler: KB8TYJ

----- Original Message ----- 
From: "Bob, K8LR" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, August 25, 2013 3:10 PM
Subject: Re: Speaking of Digital:


> Hi,
>
> I have an HD radio here and it works well on A M and FM provided there is 
> a
> good signal and very little background noise.  The A M digital sounds like
> FM when it is working but it puts a 5 second delay in to the broadcast. 
> The
> same thing is true on FM, but you have to be in a good listening room or
> wear headphones to really appreciate the difference in the digital FM 
> sound
> as the digital sound over fm sounds more like the sound from a cd player.
> Most broadcast stations now delay both the normal broadcast to match the
> digital delay so that when a radio jumps back and forth, the switch  over 
> is
> not so disorienting.
>
> I've never used an HD auto radio, but Ifigured that multipath and fading
> would cause problems.
>
> Bob, K8LR, [log in to unmask]
>
> ----- Original Message ----- 
> From: "Tom Behler" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Sunday, August 25, 2013 2:51 PM
> Subject: Speaking of Digital:
>
>
> Hi, everyone.
>
> The ongoing discussion regarding D Star, and audio quality reminded me of
> something I recently experienced, and meant to bring up to the list.
>
> As many of you may recall, the XYL and I recently purchased a new vehicle
> that has an HD radio in it.
>
> Well, thanks to the help of some on the list regarding how best to
> understand and use the new HD capabilities while traveling, I believe I 
> have
> mastered the main functions of the radio pretty thoroughly now.
>
> However, I have to say that digital A M leaves a tremendous amount to be
> desired, in my opinion.
>
> For example, while traveling through the Chicago metro area from Michigan 
> on
> our way to and from the St. Louis area several weeks ago, I tried 
> listening
> to WBBM  AM 780 with the new digital radio, and the experience was 
> actually
> quite anoying.  I'd say that as we got 30 miles or so on either side of
> Chicago, the digital AM signal kept switching on and off, to be replaced 
> by
> a much degraded analog signal.  Perhaps there is a way to turn the digital
> AM reception mode off in this particular radio, but I have not found it 
> yet.
>
> We are going to be traveling through quite a few metropolitan areas on our
> upcoming family visitation trip, so I'll have time to play with it a bit
> more, but I really am wondering now about the usefulness of digital AM
> radio.
>
> Tom Behler: KB8TYJ
>