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Listening to WJR 710 Detroit from Central Ohio, in scattered
thunderstorms, the lightning crashes are not heard, but rather
it just drops into the analog channel for a while until the
digital recovers.

If lightning crashes are rare enough so they aren't likely to
come in pairs, you never hear a lightning crash.

In heavier storms, the station becomes unlistenable, as it is
in analog alone.

That you don't hear the lightning crash means that the digital
and analog signals happen at different times, by at leash the
length of a static crash.

Perhaps the analog is delayed by the receiver, and the digital by
the transmitter, I don't know.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

MW HD time diversity
 

central Ohio NEVER has thunderstorms or lightning

Quit Fibbing : D


"Ron Hardin" wrote in message
...
Listening to WJR 710 Detroit from Central Ohio, in scattered
thunderstorms, the lightning crashes are not heard, but rather
it just drops into the analog channel for a while until the
digital recovers.

If lightning crashes are rare enough so they aren't likely to
come in pairs, you never hear a lightning crash.

In heavier storms, the station becomes unlistenable, as it is
in analog alone.

That you don't hear the lightning crash means that the digital
and analog signals happen at different times, by at leash the
length of a static crash.

Perhaps the analog is delayed by the receiver, and the digital by
the transmitter, I don't know.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

MW HD time diversity
 

On Thu, 22 Mar 2007 18:25:21 +0000, Ron Hardin wrote:
That you don't hear the lightning crash means that the digital
and analog signals happen at different times, by at leash the
length of a static crash.

Perhaps the analog is delayed by the receiver, and the digital by
the transmitter, I don't know.

Both are delayed at the transmitter.

It takes time to do the data compression for the digital signal.

The analog is delayed intentionally, to ensure it comes out at the same
time as the digital so that things don't "jump" if (as you heard) it
blends to analog. I have heard FM stations that didn't get it right, and
did jump when going to/from analog. It's possible on AM too but I haven't
heard that yet.

There is also a bit of delay in the receiver - for decompression of
digital. The receiver also delays the analog to match. At least with the
BA receiver, this happens even if the station isn't transmitting IBOC. It
can be interesting to tune in a non-IBOC AM station on the IBOC receiver,
and simultaneously tune in the same station on an analog receiver. The
audio on the IBOC receiver will be noticeably delayed relative to the
analog set, even though the station isn't transmitting a digital signal.

MW HD time diversity
 

"Doug Smith W9WI" wrote in message
...
On Thu, 22 Mar 2007 18:25:21 +0000, Ron Hardin wrote:
That you don't hear the lightning crash means that the digital
and analog signals happen at different times, by at leash the
length of a static crash.

Perhaps the analog is delayed by the receiver, and the digital by
the transmitter, I don't know.

Both are delayed at the transmitter.

It takes time to do the data compression for the digital signal.

The analog is delayed intentionally, to ensure it comes out at the same
time as the digital so that things don't "jump" if (as you heard) it
blends to analog. I have heard FM stations that didn't get it right, and
did jump when going to/from analog. It's possible on AM too but I haven't
heard that yet.

There is also a bit of delay in the receiver - for decompression of
digital. The receiver also delays the analog to match. At least with the
BA receiver, this happens even if the station isn't transmitting IBOC. It
can be interesting to tune in a non-IBOC AM station on the IBOC receiver,
and simultaneously tune in the same station on an analog receiver. The
audio on the IBOC receiver will be noticeably delayed relative to the
analog set, even though the station isn't transmitting a digital signal.


So much for having a bunch of radios on the same station at a kegger or
whatever.. one guy running a craptacular IBOC radio would throw the whole
works off.




--
Posted via a free Usenet account from http://www.teranews.com

MW HD time diversity
 

Doug Smith W9WI wrote:
The analog is delayed intentionally, to ensure it comes out at the same
time as the digital so that things don't "jump" if (as you heard) it
blends to analog. I have heard FM stations that didn't get it right, and

They apparently aren't transmitted at the same time, though, or the lightning
crash would wipe out both versions of the same audio, and it doesn't. When the
digital is wiped out, the analog is lightning-free, even though they would both
come out of the speaker at the same time.

--
Ron Hardin


On the internet, nobody knows you're a jerk.

MW HD time diversity
 

On Fri, 23 Mar 2007 08:16:54 +0000, Ron Hardin wrote:
They apparently aren't transmitted at the same time, though, or the lightning
crash would wipe out both versions of the same audio, and it doesn't. When the
digital is wiped out, the analog is lightning-free, even though they would both
come out of the speaker at the same time.

Sorry, looks like I missed your point the first time...

Don't really have a good explanation for that observation...