time delays on dab vs analogue
 

"Ian Jackson" wrote in message
...
In message , Bill Wright
writes

"charles" wrote in message
.. .
In article ,
Max Demian wrote:
"Norman Wells" wrote in message
...
Max Demian wrote:
Sounds rather digital to me, if it matters.

Does anyone know how the analogue clocks adjust when the clocks go
back?
Do they buzz backwards, or just stop for an hour?

As a young child in hospital I watched the ward clock adjust itself at a
rapid rate. I can't remember why it did this, but years later I learnt
that
all the clocks in the hosputal were controlled and powered by electrical
pulses, and could all be adjusted together.

A lot of factories had clocks like this. I don't know if they could
actually work as 'normal' clocks. The benefits of this technology would be
that there would be no arguments about clocking on and off times, and also
that there was no point in the workers nicking them.

They usually advanced half a minute at a time, controlled by a 'Synchronome'
pendulum clock, from the main manufacturer of master clocks for factories,
offices, railway stations and public buildings.

--
Max Demian

time delays on dab vs analogue
 

"charles" wrote in message
...
In article ,
Max Demian 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 . . .

How can they play them before they are sent from Herstmonceux?

because they haven't "been sent from Herstmonseaux" for at least 20 years.
The 'pips' come from a generator in BH. I'm sure it could be adjusted to
be a few seconds early - or even 14 minutes and 53 seconds late.

If that's true, perhaps you should update Wikipedia:
http://en.wikipedia.org/wiki/Greenwich_Time_Signal

--
Max Demian

time delays on dab vs analogue
 

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

I have, I have! I reckon it would not be beyond the wit of the BBC to
play the preceding programme early as well. All they need to do is
alter the clocks at Broadcasting House so they are a few seconds in
front of the rest of us.

Given I assume you're talking about a national service like R2 or R4, what
about those listening on FM? If everything was recorded it would be just
possible - but so much on those is live.
What difference does it make if it's live? Just perform it seven secs
earlier.

Bill

time delays on dab vs analogue
 

On Wed, 21 Oct 2009 08:44:28 +0100, Ian Jackson
wrote:

In message , Bill Wright
writes

"charles" wrote in message
.. .
In article ,
Max Demian wrote:
"Norman Wells" wrote in message
...
Max Demian wrote:
Sounds rather digital to me, if it matters.

Does anyone know how the analogue clocks adjust when the clocks go back?
Do they buzz backwards, or just stop for an hour?

As a young child in hospital I watched the ward clock adjust itself at a
rapid rate. I can't remember why it did this, but years later I learnt that
all the clocks in the hosputal were controlled and powered by electrical
pulses, and could all be adjusted together.

A lot of factories had clocks like this. I don't know if they could
actually work as 'normal' clocks. The benefits of this technology would
be that there would be no arguments about clocking on and off times, and
also that there was no point in the workers nicking them.

There are some examples of master and secondary clocks he
http://clockhistory.com/setclocks/de...ity/index.html


--
Peter Duncanson
(in uk.tech.digital-tv)

time delays on dab vs analogue
 

"Max Demian" wrote in message
...
because they haven't "been sent from Herstmonseaux" for at least 20
years.
The 'pips' come from a generator in BH. I'm sure it could be adjusted to
be a few seconds early - or even 14 minutes and 53 seconds late.

If that's true, perhaps you should update Wikipedia:
http://en.wikipedia.org/wiki/Greenwich_Time_Signal


Umm, that page says:
The pips for national radio stations and some local radio stations are timed
relative to UTC, from an atomic clock in the basement of Broadcasting House

Did someone already update it?

time delays on dab vs analogue
 

In article ,
says...
In message , Bill Wright
writes

As a young child in hospital I watched the ward clock adjust itself at a
rapid rate. I can't remember why it did this, but years later I learnt
that
all the clocks in the hosputal were controlled and powered by electrical
pulses, and could all be adjusted together.

A lot of factories had clocks like this. I don't know if they could
actually work as 'normal' clocks. The benefits of this technology would be
that there would be no arguments about clocking on and off times, and also
that there was no point in the workers nicking them.

They usually advanced half a minute at a time, controlled by a 'Synchronome'
pendulum clock, from the main manufacturer of master clocks for factories,
offices, railway stations and public buildings.

I think most of these master clocks were based Hipp, rather than
Synchronome, movements. (Invented by Mathias Hipp around 1830.)

They were also used by the GPO in telephone exchanges where they not
only produced 30 second pulses for the clocks but also 6 second pulses
for call timing/charging purposes (all charging periods being multiples
of six seconds).

http://www.britishtelephones.com/clocks/clock36.htm

The action of the Hipp toggle can be seen he

http://www.youtube.com/watch?v=lmx5iy4qwhI
http://www.electric-clocks.nl/clocks...ation-Hipp.htm

There were other types, including the Pulsynetic:

http://www.mridout.freeserve.co.uk/pulsynetic.htm
http://www.mridout.freeserve.co.uk/ecs.htm

I think most of the clocks (of various types) were made by Gents in
Leicester.
--

Terry

time delays on dab vs analogue
 

In article ,
says...

Max Demian wrote:

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.

I think Max was referring to the Radio Controlled variety!

My Smiths doesn't seem to do anything straight away - I have watched it
a couple of times when the clocks go on at 1am - but it sorts itself out
by morning.

I assume that when you're not looking, it advances to the new time in
exactly the same way as it would if it and you'd replaced the battery.

It's a bit odd, really, because you have no way of telling if it's
receiving a usable signal until, after a long delay, it starts whirring
round at high speed!

I wonder if the receiver is only switched on every now and again for a
short period, for battery economy. After all, a quartz clock doesn't
drift noticeably over a few hours, no matter how fussy you are

--

Terry

time delays on dab vs analogue
 

In article ,
says...

"Max Demian" wrote in message
...
"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 . . .

How can they play them before they are sent from Herstmonceux?

Easy. Record the ones sent for the previous hour and play them back.

Bill

Actually, the Beeb have been generating their own pips for a very long
time now ...

--

Terry

time delays on dab vs analogue
 

On Wed, 21 Oct 2009 14:38:16 +0100, Terry Casey wrote:

I wonder if the receiver is only switched on every now and again for a
short period, for battery economy.

I suspect that most radio controlled clocks and watches only check the
radio time signal once per hour.

I have a Braun alarm clock

http://cgi.ebay.co.UK/BRAUN-LUBS-DB-12-fsl-ALARM-CLOCK--DIETER-RAMS-ERA_W0QQitemZ140351519969QQcmdZViewItemQQimsxq2009 1018?IMSfp=TL091018139001r10699

which displays a circle outline on its LCD when it is trying to synchronize,
and this only appears about 7 seconds before the hour, and if it locks with
the time signal, a symbol appears within the circle (which you can see
on the photograph on eBay).

time delays on dab vs analogue
 

"Terry Casey" wrote in message
om...
In article ,
says...
In message , Bill Wright
writes

As a young child in hospital I watched the ward clock adjust itself at
a
rapid rate. I can't remember why it did this, but years later I learnt
that
all the clocks in the hosputal were controlled and powered by
electrical
pulses, and could all be adjusted together.

A lot of factories had clocks like this. I don't know if they could
actually work as 'normal' clocks. The benefits of this technology would
be
that there would be no arguments about clocking on and off times, and
also
that there was no point in the workers nicking them.

They usually advanced half a minute at a time, controlled by a
'Synchronome'
pendulum clock, from the main manufacturer of master clocks for
factories,
offices, railway stations and public buildings.

I think most of these master clocks were based Hipp, rather than
Synchronome, movements. (Invented by Mathias Hipp around 1830.)

They were also used by the GPO in telephone exchanges where they not
only produced 30 second pulses for the clocks but also 6 second pulses
for call timing/charging purposes (all charging periods being multiples
of six seconds).

http://www.britishtelephones.com/clocks/clock36.htm

I guess that the constant amplitude feature must have compensated for the
extra complication involved in the toggle mechanism.

There were other types, including the Pulsynetic:

http://www.mridout.freeserve.co.uk/pulsynetic.htm
http://www.mridout.freeserve.co.uk/ecs.htm

Those ones appear to work in a similar way to (what I regard as) the
'Synchronome' type, especially the second one.

--
Max Demian