Re: [IRCA] IBOC TIME LAG

["Craig Healy" <bubba@xxxxxxxxxxxxxxxxxxxx>]

> > I'll ignore the 8 second difference in the WBZ audio between analog
> > and digital.
>
> Craig, please describe what happens when you experience the 8 second
> time difference. Does the JVC pop back and forth between the out-of-
> sync IBOC-vs-analog audio or does it just die out when the IBOC
> signal isn't strong enough? So all on-the-hour time pips are 8
> seconds late on IBOC?

On WBZ the digital audio is a full 8 seconds behind the analog, which is
real time.  The analog audio is supposed to be delayed so there is a time
sync between the two.  However, WBZ relies heavily on off-air cues for
traffic and field reporters so it has been impossible for them to do this.
They are looking at a different feed and receiver system to fix this for
their talent.  My guess is that they are banking on there being so few
receivers out there that nobody notices.  Or, they feel that they have
enough signal that it will be digital all the time.  On point 1 they may be
correct.  On point 2 they are wrong.  Bridges and local interference are
enough to shunt it back to analog, with the expected garble of continuity.
I've noticed the ignition interference in my truck causes a coverage hit,
and that truck has been modified to be pretty quiet.  Even some noisy
traffic light controllers cause problems.

If the JVC is left in "auto", it jumps back and forth.  In locked digital,
it simply dies out.  In analog it's just another radio.

WHJJ has the audio synchronized properly.  On FM, WZLX has the 8 second
difference, while WMJX is correct.

Yes, there is a delay.  I believe Tom Ray said he has advanced the WOR-710
TOH time pip so theirs is correct.  I can't tell as the WOR IBOC signal
stubbornly refuses to decode, even after dark here.  Despite loops, despite
longwires, amps and tuners.  Nada.  Odd, really.  At sunset WOR is really
strong in Providence.

Craig Healy
Providence, RI


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