On Fri, 25 May 2007 14:05:36 +0100, Steve Pardoe wrote:

Sorry to be OT, but I just wondered whether there were others who
were now experiencing problems since the relocation of the MSF
transmitter up north to Anthorn from Rugby. I can get sync with one
clock in one room (but not the room I need it!), but with a home made
one, it seems to be less sensitive and its a no go now.

My LaCrosse w/s has a built-in MSF and it seems still to be in sync,
though (as before) not 24/7. I have some interest in this, because in
the early eighties (getting even further OT, but, hey, it's nearly the
weekend) I designed a single-chip MSF decoder which drove an
alphanumeric LCD, quite a novelty back then, and was the first of its
kind (I was even invited to the NPL to talk about it). I'm afraid that
there are so many other accurate time sources available now (GPS for
one, internet timeservers for another) that MSF is probably only of
domestic / novelty interest, and few of any influence will complain if
it's not as reliably received as it used to be.

Steve P

My LaCrosse w/s is no longer in sync (and worse it has gained over a
minute already) - I had not noticed so thanks for the warning (I'll have
to update my software to keep it in sync instead). Every cloud has a
silver lining at least I'll be able to force the w/s to stay on gmt time
without changing the timezone. An oregon clock upstairs is still in
perfect sync ...

Bob
http://www.hartsleap.com/weather

"Dave Liquorice" wrote in message
ll.com...
On Fri, 25 May 2007 14:05:36 +0100, Steve Pardoe wrote:

I'm afraid that there are so many other accurate time sources available
now (GPS for one, internet timeservers for another)

If you are into having seriously accurate time you take all those sources,
compare them against each other and then make your own mind up. And where
do you think internet time servers get their reference from? Standard time
and frequency services and/or GPS.

I'm sure that's right for a lot of users, but surely a landline from
Teddington will be more reliable than MSF?

that MSF is probably only of domestic / novelty interest, and few of any
influence will complain if it's not as reliably received as it used to
be.

Apart from the time encoded into the carrier, the carrier is also a
frequency standard.

Indeed it is, but again I wonder how many bodies now use it ; and of course
a constant sinewave is much easier to lock to than once-per-second
modulation.

While we're on the off-topic of time, it strikes me as perverse that the BBC
(and perhaps others) persist in broadcasting the pips on digital TV, even
though they are a couple of seconds late (I imagine DAB radio is the same,
but I haven't got one).

Steve P

In message , Steve Pardoe
writes

"Dave Liquorice" wrote in message
ill.com...
On Fri, 25 May 2007 14:05:36 +0100, Steve Pardoe wrote:

I'm afraid that there are so many other accurate time sources available
now (GPS for one, internet timeservers for another)

If you are into having seriously accurate time you take all those sources,
compare them against each other and then make your own mind up. And where
do you think internet time servers get their reference from? Standard time
and frequency services and/or GPS.

I'm sure that's right for a lot of users, but surely a landline from
Teddington will be more reliable than MSF?

that MSF is probably only of domestic / novelty interest, and few of any
influence will complain if it's not as reliably received as it used to
be.

Apart from the time encoded into the carrier, the carrier is also a
frequency standard.

Indeed it is, but again I wonder how many bodies now use it ; and of course
a constant sinewave is much easier to lock to than once-per-second
modulation.

While we're on the off-topic of time, it strikes me as perverse that the BBC
(and perhaps others) persist in broadcasting the pips on digital TV, even
though they are a couple of seconds late (I imagine DAB radio is the same,
but I haven't got one).

And about 15 seconds late via broadband.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England

While we're on the off-topic of time, it strikes me as perverse that the BBC
(and perhaps others) persist in broadcasting the pips on digital TV, even
though they are a couple of seconds late (I imagine DAB radio is the same,
but I haven't got one).

And about 15 seconds late via broadband.

Norman.

At the risk of drifting even more OT, why is digital TV about 2 secs
out of synch with analog? It's a bit strange when you switch from one
to the other and here the last 2 words again.

Graham
Penzance

In message om, "Jack
)" writes
I offer you a solution James - move house.

I'm sure someone could tell you which area has the best coverage, but
I guess you'd find house prices inflated there because of the
availability of the signal. That might put you off the idea.

Incidentally, I have a Casio watch that is still on the market for
about a tenner. But I won't part with mine as it is accurate to 1
second per month. But the straps wear out. So I pay a fiver every
two years or so for a new strap. I guess I must be on number 5 or 6
by now. I have a back-up watch but that's rubbish and drifts by the
best part of two seconds EACH WEEK!

Jack


Thanks Jack - I knew I could rely on you to think outside the box!!

The thing is - the first MSF clock is one I built up from single
components - it's got about three layers of CMOS chips in the days when
the CMOS cook book was never far from my bench. How can I possibly
explain to my old friend that he's redundant?!!! No crystal back-up so I
could always tell when Rugby was down for maintenance. It was
fascinating tuning the aerial with an ancient Textronic scope to get the
cleanest signal, but I'm probably boring you now...

Perhaps I could turn it into a new marketing point if we ever move.
Guaranteed to be free of 60kHz signals (T-mobile is no good either
mind!) Come to the sunny seaside and be free of LF radio emmissions.

James.
--
James Brown

On Fri, 25 May 2007 15:48:14 GMT, Chris Mantle wrote:

Kempston, Bedford

Well they probably still have the old signal ringing in their ears...

--
Cheers
Dave. pam is missing e-mail

On Fri, 25 May 2007 18:25:27 +0100, Steve Pardoe wrote:

I'm sure that's right for a lot of users, but surely a landline from
Teddington will be more reliable than MSF?

But you can't get a straight bit of copper from BT now only digital stuff
in one form or another with all the built in and variable latency etc. Not
to mention the cost, not only for installation but rental as well.

Indeed it is, but again I wonder how many bodies now use it ; and of
course a constant sinewave is much easier to lock to than
once-per-second modulation.

If one is interested in seriously accurate time you don't lock your clock
to an external source you just compare your tuned and accurate clock with
the standards over fairly long periods of time (hours to days). Think
about it, MSF is maintained to better than 2 x 10^-12 (2 millionths of a
millionth of 1s) your own clock will have similar accuracy. How long will
it take for any drift between the two to become measurable? These aren't
things you switch on then seconds later you have accurate time, they take
a long time to stabilse and then synchoronise. The on/off nature of the
60kHz MSF carrier is barely relevant.

While we're on the off-topic of time, it strikes me as perverse that the
BBC (and perhaps others) persist in broadcasting the pips on digital TV,
even though they are a couple of seconds late

Because they are part of the real analogue network and all these other new
fangled services are just hanging on the back of that. There was some
talk about running BH a set amount ahead of clock time and applying
various delays in the various feeds but when you really start looking at
the implications it rapidly becomes impractical.

--
Cheers
Dave. pam is missing e-mail

On 25 May 2007 12:37:46 -0700, Graham Easterling wrote:

At the risk of drifting even more OT, why is digital TV about 2 secs
out of synch with analog?

Which digital platform are you watching?

DSAT has the 44,000 odd mile round trip up to the bird and back on top of
the delays inherent in the digital processing. Terrestial digital has high
levels of compression applied and the statistical multiplexing they all
take time to perform.

--
Cheers
Dave. pam is missing e-mail

"Dave Liquorice" wrote in message
ll.com...
On Fri, 25 May 2007 18:25:27 +0100, Steve Pardoe wrote:

While we're on the off-topic of time, it strikes me as perverse that the
BBC (and perhaps others) persist in broadcasting the pips on digital TV,
even though they are a couple of seconds late

Because they are part of the real analogue network and all these other new
fangled services are just hanging on the back of that. There was some
talk about running BH a set amount ahead of clock time and applying
various delays in the various feeds but when you really start looking at
the implications it rapidly becomes impractical.

Thanks for that.

SP

in 225405 20070525 094014 James Brown wrote:
Sorry to be OT, but I just wondered whether there were others who were
now experiencing problems since the relocation of the MSF transmitter up
north to Anthorn from Rugby. I can get sync with one clock in one room
(but not the room I need it!), but with a home made one, it seems to be
less sensitive and its a no go now. I e-mailed the folks, but got their
standard response of which the gist is - better for some worse for
others - tough!

Cheers
James
--
James Brown

I have 2 MSF clocks here in Portsmouth. One is tuned to Anthorn and gets a signal
about 10% of the time, the other is tuned to Frankfurt and AFAIK hasn't received a signal
since the clocks went forward (was fine up to then).
The first I can understand but the latter I can't.