time delays on dab vs analogue
 

On Tue, 20 Oct 2009 11:59:09 +0100, Brightside S9 wrote:

It could have "gone out" (fusion ceased) 10^5 to 10^6 years ago.
Looking at it won't help, since you can't *see* the neutrinos that
indicate that fusion is still ongoing. But if they stop then we are in
trouble.

It was interesting to learn that the Sun also protects the earth and its
inhabitants from dangerous cosmic radation by way of the heliosphere.

QUOTE

October 18, 2009

NASA scientists have discovered a mysterious ribbon around our solar
system —- a stripe made of hydrogen —- that defies all current expectations
about what the edge of the solar system might look like.

UNQUOTE

Full story at

http://www.npr.ORG/templates/story/story.php?storyId=113914677

time delays on dab vs analogue
 

The message
from "Brian Gaff" contains these words:

The problem with trying to get this right is that every set has a different
delay. I know that the delay on my freeview and dab are different, and
indeed a second dab I borrowed is some 2 seconds nearer the right
time than
the Pure one.

I'd say that yes, it is all wrong. However, worse is to come.
Sometimes when
i use my scanner, i can pick up bbc radio talkback for interviews etc, this
is quite often some three seconds ahead of the output from my fm tuner, so
the time signals on the distribution networks are hardly that accurate
either.

Just remember, if the sun goes out, you will not know for 8 minutes.

Brian

8 minutes and 20 seconds, actually ;-) Average distance is 93 million
miles (Astronomical Unit) and the speed of light in a vacuum is 186,000
miles per second[1].

[1] Or, if you prefer metric units, 150 million Km and 300,000Km/s.
Either way, it's a propagation delay of some 500 seconds.

--
Regards, John.

Please remove the "ohggcyht" before replying.
The address has been munged to reject Spam-bots.

time delays on dab vs analogue
 

"Norman Wells" wrote in message
...
Max Demian wrote:
"Norman Wells" wrote in message
...
Max Demian wrote:

The number of seconds delay depends on your hardware as well as the
transmission.

I guess that when (and if) analogue radio transmissions end the BBC
will give up the GMT pips.

Most people have at least one radio controlled clock in the house.

Ah, but is that analogue radio or digital?

I kind of expected that smartarse remark:
http://en.wikipedia.org/wiki/Time_from_NPL#Protocol

Sounds rather digital to me, if it matters.

Then it'll be late because it apparently depends on your hardware.

Not *everything* digital is slow.

Does anyone know how the analogue clocks adjust when the clocks go
back?

If they're anything like the ones I have, the little knob on the back has
something to do with it.

And whether it is a Mickey or a Minnie Mouse model.

--
Max Demian

time delays on dab vs analogue
 

"Dave Plowman (News)" wrote in message
...
In article ,
Bill Wright wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
comp.john wrote:
When the time signal arrives, which is the accurate one. DAB or
analogue?

Rather obviously the earliest one - as you can delay something, but not
make it happen before it does, as it were. If you could, you've just
invented time travel.

No, clever clogs, that's ********. The BBC could play the pips early so
as to make them more-or-less right for DAB. In theory . . .

And go across the end of the preceding prog? Or to avoid this you'd need a
long gap between live progs. And of course the pips are usually in between
live spots.

Not a theory you've thought through, Bill. ;-)

If you just incorporate the DAB time delay into all the scheduling then the
whole thing is broadcast about six seconds early, including the program
changeover and pips.

The only thing you will have to do is to have a 'DAB time' clock for
anything with a studio (or other venue) audience so they don't get too
confused.

time delays on dab vs analogue
 

"Bill Wright" wrote in message
...

"Dave Plowman (News)" wrote in message
...
In article ,
comp.john wrote:
When the time signal arrives, which is the accurate one. DAB
or
analogue?

Rather obviously the earliest one - as you can delay
something, but not
make it happen before it does, as it were. If you could,
you've just
invented time travel.

No, clever clogs, that's ********. The BBC could play the pips
early so as to make them more-or-less right for DAB. In theory
. . .

Bill



Indeed I suspect they may actually do that as there is
distribution delays on the FM system as well. The only really
accurate method is an off-air clock - and despite what one poster
said you can get alarmclocks etc with off-air.

The real problem Bill is that different DAB radios take different
times to decode - in fact we have one that takes longer in the
kitchen where the signal is not so good (occasional bubbling mud)
than it does when in a front bedroom and gets a better signal
(compared against an off-air clock.) Must be that when the
decoding is working harder it takes longer?


--
Woody

harrogate three at ntlworld dot com

time delays on dab vs analogue
 

In article ,
Max Demian wrote:
Not *everything* digital is slow.

Digital radio mics put an audible delay in the audio compared to an
analogue one and I'd guess they tried their best to minimise this.

--
*I'm already visualizing the duct tape over your mouth

Dave Plowman London SW
To e-mail, change noise into sound.

time delays on dab vs analogue
 

In message , David WE Roberts
writes

"Dave Plowman (News)" wrote in message
...
In article ,
Bill Wright wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
comp.john wrote:
When the time signal arrives, which is the accurate one. DAB or
analogue?

Rather obviously the earliest one - as you can delay something, but not
make it happen before it does, as it were. If you could, you've just
invented time travel.

No, clever clogs, that's ********. The BBC could play the pips early so
as to make them more-or-less right for DAB. In theory . . .

And go across the end of the preceding prog? Or to avoid this you'd need a
long gap between live progs. And of course the pips are usually in between
live spots.

Not a theory you've thought through, Bill. ;-)

If you just incorporate the DAB time delay into all the scheduling then
the whole thing is broadcast about six seconds early, including the
program changeover and pips.

The only thing you will have to do is to have a 'DAB time' clock for
anything with a studio (or other venue) audience so they don't get too
confused.

But is the delay constant? I've always thought that it depended on the
amount of processing and multiplexing going on at any instant (ie on the
content of audio signals being stuffed together).
--
Ian

time delays on dab vs analogue
 

In an earlier contribution to this discussion,
David WE Roberts wrote:


If you just incorporate the DAB time delay into all the scheduling
then the whole thing is broadcast about six seconds early, including
the program changeover and pips.


So how would that work with *live* broadcasts?
--
Cheers,
Roger
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time delays on dab vs analogue
 

On Tue, 20 Oct 2009 18:54:22 +0100, "Woody"
wrote:

"Bill Wright" wrote in message
.. .

"Dave Plowman (News)" wrote in message
...
In article ,
comp.john wrote:
When the time signal arrives, which is the accurate one. DAB
or
analogue?

Rather obviously the earliest one - as you can delay
something, but not
make it happen before it does, as it were. If you could,
you've just
invented time travel.

No, clever clogs, that's ********. The BBC could play the pips
early so as to make them more-or-less right for DAB. In theory
. . .

Bill



Indeed I suspect they may actually do that as there is
distribution delays on the FM system as well. The only really
accurate method is an off-air clock - and despite what one poster
said you can get alarmclocks etc with off-air.

I believe R4 long wave is recognised as the most accurate time signal.

time delays on dab vs analogue
 

In article , Dave Plowman (News) wrote:
Not *everything* digital is slow.

Digital radio mics put an audible delay in the audio compared to an
analogue one and I'd guess they tried their best to minimise this.

Not to mention flat screen monitors. Presumably if they delay the
pictures by the same amount that the radio-mics delay the sound, it
should be about right when played back on such a monitor, even if it
sounds out of sync while recording the performance.

Television never used to be able to give us out of sync sound and
picture. It took a lot of technical innovation to achieve this. Now
it's just like film, so I guess it must be good...

Rod.
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