Hi Jim,
Yes, now, most digital stations delay the normal A M transmission so that
you won't notice the 5 second delay present in the digital signal. When
digital hd radio first started, they didn't time delay the broadcast and it
was really confusing if the station dropped out of digital and back to
normal and back to digital again.
Bob, K8LR, [log in to unmask]
----- Original Message -----
From: "Jim Gammon" <[log in to unmask]>
To: "Bob, K8LR" <[log in to unmask]>
Sent: Sunday, August 25, 2013 7:45 PM
Subject: HD radios
Bob, I have a Sony HD radio and listen to a local news station on
AM. Like you said, it sounds like FM in the HD mode, but if I
play an analog radio on the same station right next to the HD
radio, they are nearly in sync, nowhere near a 5 second delay. I
would think an HD radio in a car would sound pretty bad in fringe
areas unless you could manually turn the HD off. When I first
got my Sony, I tried to hear Knx LA from up near San Francisco
and it would never go into HD mode because the signal was not
strong enough, even when using a tunable AM antenna. Jim WA6EKS
----- Original Message -----
From: "Bob, K8LR" <[log in to unmask]
To: [log in to unmask]
Date sent: Sun, 25 Aug 2013 15:10:53 -0400
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
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