OT.... but I need help

In message , Gene E. Bloch
writes:
On Fri, 2 Nov 2012 21:40:54 +0000, J. P. Gilliver (John) wrote:
[]
What's more, they advertise these clocks (and watches) as "accurate to a
second in a million years" (or that sort of thing). Which, of course,
they're not: the clock they're _linked_ to _may_ be. Can't see how they
get away with such claims, but they obviously do.

Well, people like you and me notice it, so they aren't really getting
away with it :-)

By "get away with it", I mean they aren't punished (fined) by whatever
agency keeps an eye on advertising. (In the UK, it's the ASA -
advertising standards authority - who are worthless; their main sanction
seems to be to tell the advertiser that the ad. must not appear in that
form again, which delights the advertisers: they just say "sorry
teacher, won't do it again", and go on to write similarly misleading
copy for a different product. Such as a recent one I saw for a portable
TV described as "high resolution", which had a vertical pixel count of
less than 500 pixels - even stated in the same ad.!; see if you can spot
their excuse for getting away with that one.)

[Yes, I know about "caveat emptor" (let the buyer beware), but where
technical matters are concerned at the very least, I do think the less
knowledgeable should be protected.]
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Or Margo Leadbetter sayig "Jerry" in a voice that could melt a box of After
Eights. - David Butcher in RT, 12-18 May 2012.

Gene E. Bloch wrote:
On Fri, 02 Nov 2012 18:59:39 +0000, Ed Cryer wrote:

Paul wrote:
Ed Cryer wrote:
Drew wrote:
On 11/1/2012 12:04 PM, Ed Cryer wrote:
In our local sports centre swimming pool there's a clock on the
wall. It
keeps good time. I've relied on it for years to time myself.
However, every day at 4-00pm exactly it goes into overdrive, and sweeps
round covering many hours in a few seconds. Then it resets at just
after
4-00pm, and continues normally.

I've pointed it out to many fellow swimmers; and they stare in
amazement, raised eyebrows and a dim expression over the facial
features
and say they don't know.

The other day I finally gave in and asked at Reception what it was all
about. She told me that that was the only clock in the Centre that did
that, that they weren't interconnected and that she didn't know why.

My best guess is that it's a radio clock, and it self-adjust every day
at 4-00pm. But I've googled for "clock speeds up at 4-00pm" and the
like
and haven't found the answer.

Some one here must have met one of these things. If so then let me know
more.

Ed

Possible atomic clock of some kind?

I have a strong suspicion you're right here. Everybody else seems to
have gone for radio-control (I did myself as first guess), but look
what googling has produced.

It looks just like this;
http://www.walmart.com/ip/14-Analog-...Pearl/13443480

And then take a look at these hits for images on "Analog Atomic Wall
Clock"; there are zillions.
http://tinyurl.com/bt95lv3

There must be quite a lot of these things in use around the world. The
write-up says;
Radio-Controlled Atomic Time
Automatically sets to exact time
Accurate to the second
Automatically updates for daylight saving time (on/off option)
4 time zone settings
14'' Plastic Frame
Simple Operation: Insert One AA Alkaline Battery (not included)
After signal is received, press Time Zone button to set
Four Time Zone Settings
Daylight Saving Time Option On/Off
Manual Reset Button

Ed

According to this, that product uses WWVB.

http://www.lacrosse-clock.com/lacrosse_technology.htm

The signal strength varies through the day. So if it
was having a reception problem, you'd wait until the
signal reached peak strength, to see if the clock could
pick it up.

http://www.nist.gov/pml/div688/grp40/radioclocks.cfm

( http://en.wikipedia.org/wiki/WWVB )

Amazing it runs off one AA alkaline cell. So while
you don't have to set the time, the battery is still
going to need changing.

Paul



I find that hard to believe, too. My little Acctim digital radio clock
needs two AAs. But it also displays date, temp and phase of moon. Mind
you, I can't recall having ever changed the batts since I got the thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).


I've been looking for a use for that moon phase display.
I thought it might come in useful if I ever become a Moslem or a Jew,
when it would indicate approaching Ramadan or Passover. But I had a
near-death experience some years back, and no religious awakening at all
in my narrow little life.
Maybe now, however, when the skies have been so cloud-covered for months
that it's nice to know what would be visible without them.

:-)
Ed

On Fri, 02 Nov 2012 12:42:07 -0700, Gene E. Bloch wrote:


I find that hard to believe, too. My little Acctim digital radio clock
needs two AAs. But it also displays date, temp and phase of moon. Mind
you, I can't recall having ever changed the batts since I got the
thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).

It's funny....I've been "into" electronics since I was a little kid, and
actively working in an electronics based field, and up until a year or two
ago, never heard the word "valve" used as a reference to a vacuum tube.

DanS wrote:
On Fri, 02 Nov 2012 12:42:07 -0700, Gene E. Bloch wrote:


I find that hard to believe, too. My little Acctim digital radio clock
needs two AAs. But it also displays date, temp and phase of moon. Mind
you, I can't recall having ever changed the batts since I got the
thing.

Ed
Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).

It's funny....I've been "into" electronics since I was a little kid, and
actively working in an electronics based field, and up until a year or two
ago, never heard the word "valve" used as a reference to a vacuum tube.

You must live outside the UK, probably in America, then.

To us here in the UK, a "tube" normally refers to a CRT as used in a TV set.

--
Tciao for Now!

John.

In message , John Williamson
writes:
DanS wrote:
[]
It's funny....I've been "into" electronics since I was a little kid,
and actively working in an electronics based field, and up until a
year or two ago, never heard the word "valve" used as a reference to
a vacuum tube.

You must live outside the UK, probably in America, then.

To us here in the UK, a "tube" normally refers to a CRT as used in a TV set.

Indeed. Here (UK), the things with heaters (filaments in US) are valves,
in US they're tubes (pronounced toobs usually, as opposed to tyoobs
which would be the UK pronunciation). Even TV would normally be referred
to as "the TV" (or "the telly") or "the box" - "on the tube" is more a
US phrase. (Also, when I was growing up, which would have been mid to
late sixties when I first came to be aware of this sort of thing, I'd
say something with valves in it - usually mains [line, US] powered - was
a "wireless", and something with transistors - usually battery powered -
was a "radio".)

The differences between our languages bring much enjoyment to me (as
well as occasional frustration)! Can't think of anything
computer-specific, other than perhaps remembering as a child chanting "a
million million is a billion, a million billion is a trillion"; we
adopted the American billion somewhere around 1980.
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Have you ever tried Chicken Tarka? It's like Chicken Tikka, only 'otter.

On Sat, 3 Nov 2012 20:47:35 +0000, "J. P. Gilliver (John)"
wrote:

Indeed. Here (UK), the things with heaters (filaments in US) are valves,
in US they're tubes (pronounced toobs usually, as opposed to tyoobs
which would be the UK pronunciation).


Just curious. Is "tyoobs" universally used in the UK? I would have
expected that in some places, it would be"tyoobs," but in other places
"toobs" would be much more common.

Just like in the US, where a word like "car" would have big
differences in pronunciation depending on what part of the country
you're in.

On 03/11/2012 11:04, J. P. Gilliver (John) wrote:
In message , Paul writes:
J. P. Gilliver (John) wrote:
In message , Fokke Nauta
writes:
[]
Well, it would only need 200 batteries to reach the anode voltage.

Fokke
One battery, containing 200 cells ... though single cells do tend to
be referred to as "batteries" these days. A car battery, or a PP3 or
PP9, is a true battery; AA, AAA, C, D, etc. are cells.

Unfortunately a language problem. Though I could have known better ...


On old vacuum radio gear, there were two sets of batteries.

No, two batteries (-:. [That was the point I was making - "battery"
strictly means, or used to, "a set of cells".]

There were large "cylinders" to be used for filaments.

Yes, the filaments - or heaters as they tend to be called in UK -
generally ran on 6.3V (three lead-acid cells in series), though some
valves had 2V or even 1.5V heaters. In UK (allegedly - I'm not old
enough to remember this!), people without mains electricity had an
"accumulator" - presumably such a 6V battery - which they took to a
local shop to get charged. (Apparently often a local cycle shop.)

And "cubes" to power B+ voltage. You might need two
of these "cubes" to get enough B+ for mobile operation.
[]
I can _just_ - this would have been in the 1970s, in a rural town in
north England - remember seeing such batteries on sale. About the shape
(and size, and IIRR weight!) of a house brick, with a three prong
connector in the middle. (I have a vague memory that it might have been
90V, but it could have been two hundred and something - or even two
different voltages, given the three prong connector.) [By the way, I
think the term "B+ voltage" is US; I'm not sure what term was used in
UK, maybe HT.]

filaments would likely be in parallel. Whereas some
radios powered from the wall, the filaments were in
series.

Indeed. If in parallel, they could be different current ratings but had
to be the same voltage (e. g. for battery/cell powered sets); if in
series, they needed to be the same current rating but could be different
voltages (provided they all added up to the supply voltage - sometimes
with a big green series resistor to drop some of it and/or limit the on
surge!).
[]

You are perfectly right!


This is just a vague recollection of some stuff my father
brought home when I was quite young. All the batteries
in this case, were flat, so there was no chance to
verify how many batteries were needed to run it. I

Well, unless you wanted to keep them as a museum exhibit, you could find
out by ripping the flat batteries apart to see how many cells they
contained (which I expect would have been ordinary 1.5 volt cells,
though of unusual shapes). I'd have thought they'd have the voltage
printed on them, though.

could have done some serious damage as an experimenter,
if those B+ batteries were working.

Paul
(-:

A fascinating diversion, this, for something like the Windows 7
newsgroup - I hope the rest don't mind! They might also enjoy
http://www.bvwtm.org.uk/tour/.

Amazing stuff there! This is great.
They still use tubes in guitar amps. I developed one with tubes, years ago.
And I used to have a radio xmittor with tubes.

In the old days there were radio receivers with tubes with the filaments
in series, so they didn't need a transformer. Plate voltage was directly
rectified from the mains.

I can remember having seen portable radio receiver equipment with tubes
in cars. Never seen those plate batteries though.

Fokke

On 02/11/2012 23:44, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 22:32:37 +0100, Fokke Nauta wrote:

On 02/11/2012 20:42, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 18:59:39 +0000, Ed Cryer wrote:

Paul wrote:
Ed Cryer wrote:
Drew wrote:
On 11/1/2012 12:04 PM, Ed Cryer wrote:
In our local sports centre swimming pool there's a clock on the
wall. It
keeps good time. I've relied on it for years to time myself.
However, every day at 4-00pm exactly it goes into overdrive, and sweeps
round covering many hours in a few seconds. Then it resets at just
after
4-00pm, and continues normally.

I've pointed it out to many fellow swimmers; and they stare in
amazement, raised eyebrows and a dim expression over the facial
features
and say they don't know.

The other day I finally gave in and asked at Reception what it was all
about. She told me that that was the only clock in the Centre that did
that, that they weren't interconnected and that she didn't know why.

My best guess is that it's a radio clock, and it self-adjust every day
at 4-00pm. But I've googled for "clock speeds up at 4-00pm" and the
like
and haven't found the answer.

Some one here must have met one of these things. If so then let me know
more.

Ed

Possible atomic clock of some kind?

I have a strong suspicion you're right here. Everybody else seems to
have gone for radio-control (I did myself as first guess), but look
what googling has produced.

It looks just like this;
http://www.walmart.com/ip/14-Analog-...Pearl/13443480

And then take a look at these hits for images on "Analog Atomic Wall
Clock"; there are zillions.
http://tinyurl.com/bt95lv3

There must be quite a lot of these things in use around the world. The
write-up says;
Radio-Controlled Atomic Time
Automatically sets to exact time
Accurate to the second
Automatically updates for daylight saving time (on/off option)
4 time zone settings
14'' Plastic Frame
Simple Operation: Insert One AA Alkaline Battery (not included)
After signal is received, press Time Zone button to set
Four Time Zone Settings
Daylight Saving Time Option On/Off
Manual Reset Button

Ed

According to this, that product uses WWVB.

http://www.lacrosse-clock.com/lacrosse_technology.htm

The signal strength varies through the day. So if it
was having a reception problem, you'd wait until the
signal reached peak strength, to see if the clock could
pick it up.

http://www.nist.gov/pml/div688/grp40/radioclocks.cfm

( http://en.wikipedia.org/wiki/WWVB )

Amazing it runs off one AA alkaline cell. So while
you don't have to set the time, the battery is still
going to need changing.

Paul



I find that hard to believe, too. My little Acctim digital radio clock
needs two AAs. But it also displays date, temp and phase of moon. Mind
you, I can't recall having ever changed the batts since I got the thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).


Well, it would only need 200 batteries to reach the anode voltage.

Fokke

Good one!

In the old days, they made batteries with about 60 cells and used tubes
that needed a B+ (that's engineer's slang for anode voltage) of 90
volts.


Yes!
I used to have a tube handbook with tubes which have a filament voltage
of 1.4 volt and an anode voltage of 90 volts. For battery use!

Wonderful days!

Fokke

Ken Blake wrote:
On Sat, 3 Nov 2012 20:47:35 +0000, "J. P. Gilliver (John)"
wrote:

Indeed. Here (UK), the things with heaters (filaments in US) are valves,
in US they're tubes (pronounced toobs usually, as opposed to tyoobs
which would be the UK pronunciation).


Just curious. Is "tyoobs" universally used in the UK? I would have
expected that in some places, it would be"tyoobs," but in other places
"toobs" would be much more common.

Just like in the US, where a word like "car" would have big
differences in pronunciation depending on what part of the country
you're in.

It normally sounds more like choobs, to be honest. I've never heard a UK
native say "toobs" except as an affectation or when taking the mickey
out of the audiophools.

--
Tciao for Now!

John.

Fokke Nauta wrote:
On 02/11/2012 23:44, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 22:32:37 +0100, Fokke Nauta wrote:

On 02/11/2012 20:42, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 18:59:39 +0000, Ed Cryer wrote:

Paul wrote:
Ed Cryer wrote:
Drew wrote:
On 11/1/2012 12:04 PM, Ed Cryer wrote:
In our local sports centre swimming pool there's a clock on the
wall. It
keeps good time. I've relied on it for years to time myself.
However, every day at 4-00pm exactly it goes into overdrive,
and sweeps
round covering many hours in a few seconds. Then it resets at just
after
4-00pm, and continues normally.

I've pointed it out to many fellow swimmers; and they stare in
amazement, raised eyebrows and a dim expression over the facial
features
and say they don't know.

The other day I finally gave in and asked at Reception what it
was all
about. She told me that that was the only clock in the Centre
that did
that, that they weren't interconnected and that she didn't know
why.

My best guess is that it's a radio clock, and it self-adjust
every day
at 4-00pm. But I've googled for "clock speeds up at 4-00pm" and
the
like
and haven't found the answer.

Some one here must have met one of these things. If so then let
me know
more.

Ed

Possible atomic clock of some kind?

I have a strong suspicion you're right here. Everybody else seems to
have gone for radio-control (I did myself as first guess), but look
what googling has produced.

It looks just like this;
http://www.walmart.com/ip/14-Analog-...Pearl/13443480

And then take a look at these hits for images on "Analog Atomic Wall
Clock"; there are zillions.
http://tinyurl.com/bt95lv3

There must be quite a lot of these things in use around the
world. The
write-up says;
Radio-Controlled Atomic Time
Automatically sets to exact time
Accurate to the second
Automatically updates for daylight saving time (on/off option)
4 time zone settings
14'' Plastic Frame
Simple Operation: Insert One AA Alkaline Battery (not
included)
After signal is received, press Time Zone button to set
Four Time Zone Settings
Daylight Saving Time Option On/Off
Manual Reset Button

Ed

According to this, that product uses WWVB.

http://www.lacrosse-clock.com/lacrosse_technology.htm

The signal strength varies through the day. So if it
was having a reception problem, you'd wait until the
signal reached peak strength, to see if the clock could
pick it up.

http://www.nist.gov/pml/div688/grp40/radioclocks.cfm

( http://en.wikipedia.org/wiki/WWVB )

Amazing it runs off one AA alkaline cell. So while
you don't have to set the time, the battery is still
going to need changing.

Paul



I find that hard to believe, too. My little Acctim digital radio clock
needs two AAs. But it also displays date, temp and phase of moon. Mind
you, I can't recall having ever changed the batts since I got the
thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).


Well, it would only need 200 batteries to reach the anode voltage.

Fokke

Good one!

In the old days, they made batteries with about 60 cells and used tubes
that needed a B+ (that's engineer's slang for anode voltage) of 90
volts.


Yes!
I used to have a tube handbook with tubes which have a filament voltage
of 1.4 volt and an anode voltage of 90 volts. For battery use!

Wonderful days!

A number of companies made sets using these. I know of at least one that
still works almost as well as the day it was made. The 90V battery used
to last a lot longer than the 1.5 V filament battery. I heard during the
1960s and 1970s of people making replacement mains power supplies for
these sets that fitted into the same space as the batteries.

--
Tciao for Now!

John.

On 03/11/2012 23:41, John Williamson wrote:
Fokke Nauta wrote:
On 02/11/2012 23:44, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 22:32:37 +0100, Fokke Nauta wrote:

On 02/11/2012 20:42, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 18:59:39 +0000, Ed Cryer wrote:

Paul wrote:
Ed Cryer wrote:
Drew wrote:
On 11/1/2012 12:04 PM, Ed Cryer wrote:
In our local sports centre swimming pool there's a clock on the
wall. It
keeps good time. I've relied on it for years to time myself.
However, every day at 4-00pm exactly it goes into overdrive,
and sweeps
round covering many hours in a few seconds. Then it resets at
just
after
4-00pm, and continues normally.

I've pointed it out to many fellow swimmers; and they stare in
amazement, raised eyebrows and a dim expression over the facial
features
and say they don't know.

The other day I finally gave in and asked at Reception what it
was all
about. She told me that that was the only clock in the Centre
that did
that, that they weren't interconnected and that she didn't
know why.

My best guess is that it's a radio clock, and it self-adjust
every day
at 4-00pm. But I've googled for "clock speeds up at 4-00pm"
and the
like
and haven't found the answer.

Some one here must have met one of these things. If so then
let me know
more.

Ed

Possible atomic clock of some kind?

I have a strong suspicion you're right here. Everybody else
seems to
have gone for radio-control (I did myself as first guess), but look
what googling has produced.

It looks just like this;
http://www.walmart.com/ip/14-Analog-...Pearl/13443480


And then take a look at these hits for images on "Analog Atomic
Wall
Clock"; there are zillions.
http://tinyurl.com/bt95lv3

There must be quite a lot of these things in use around the
world. The
write-up says;
Radio-Controlled Atomic Time
Automatically sets to exact time
Accurate to the second
Automatically updates for daylight saving time (on/off
option)
4 time zone settings
14'' Plastic Frame
Simple Operation: Insert One AA Alkaline Battery (not
included)
After signal is received, press Time Zone button to set
Four Time Zone Settings
Daylight Saving Time Option On/Off
Manual Reset Button

Ed

According to this, that product uses WWVB.

http://www.lacrosse-clock.com/lacrosse_technology.htm

The signal strength varies through the day. So if it
was having a reception problem, you'd wait until the
signal reached peak strength, to see if the clock could
pick it up.

http://www.nist.gov/pml/div688/grp40/radioclocks.cfm

( http://en.wikipedia.org/wiki/WWVB )

Amazing it runs off one AA alkaline cell. So while
you don't have to set the time, the battery is still
going to need changing.

Paul



I find that hard to believe, too. My little Acctim digital radio
clock
needs two AAs. But it also displays date, temp and phase of moon.
Mind
you, I can't recall having ever changed the batts since I got the
thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).


Well, it would only need 200 batteries to reach the anode voltage.

Fokke

Good one!

In the old days, they made batteries with about 60 cells and used tubes
that needed a B+ (that's engineer's slang for anode voltage) of 90
volts.


Yes!
I used to have a tube handbook with tubes which have a filament
voltage of 1.4 volt and an anode voltage of 90 volts. For battery use!

Wonderful days!

A number of companies made sets using these. I know of at least one that
still works almost as well as the day it was made. The 90V battery used
to last a lot longer than the 1.5 V filament battery. I heard during the
1960s and 1970s of people making replacement mains power supplies for
these sets that fitted into the same space as the batteries.


The anode supply draws only a few milliamps. Filament current was much more.
But wonderful, if one could develope a power supply that fits in the
battery compartment!

Fokke

On Sat, 03 Nov 2012 22:34:58 +0000, John Williamson
wrote:

Ken Blake wrote:
On Sat, 3 Nov 2012 20:47:35 +0000, "J. P. Gilliver (John)"
wrote:

Indeed. Here (UK), the things with heaters (filaments in US) are valves,
in US they're tubes (pronounced toobs usually, as opposed to tyoobs
which would be the UK pronunciation).


Just curious. Is "tyoobs" universally used in the UK? I would have
expected that in some places, it would be"tyoobs," but in other places
"toobs" would be much more common.

Just like in the US, where a word like "car" would have big
differences in pronunciation depending on what part of the country
you're in.

It normally sounds more like choobs, to be honest. I've never heard a UK
native say "toobs" except as an affectation or when taking the mickey
out of the audiophools.

--
Tciao for Now!


Groozie for now. ;-)

On Sat, 03 Nov 2012 14:46:35 +0000, John Williamson wrote:

DanS wrote:
On Fri, 02 Nov 2012 12:42:07 -0700, Gene E. Bloch wrote:


I find that hard to believe, too. My little Acctim digital radio
clock needs two AAs. But it also displays date, temp and phase of
moon. Mind you, I can't recall having ever changed the batts since I
got the thing.

Ed
Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).

It's funny....I've been "into" electronics since I was a little kid,
and actively working in an electronics based field, and up until a year
or two ago, never heard the word "valve" used as a reference to a
vacuum tube.

You must live outside the UK, probably in America, then.


Yes, I live on the continent of North America.


To us here in the UK, a "tube" normally refers to a CRT as used in a TV
set.

Here a "TV tube" would indicate the CRT, but other than that, tubes would
just mean vacuum tubes in a non-specific application.

On 11/3/2012 6:41 AM, DanS wrote:
On Fri, 02 Nov 2012 12:42:07 -0700, Gene E. Bloch wrote:


I find that hard to believe, too. My little Acctim digital radio clock
needs two AAs. But it also displays date, temp and phase of moon. Mind
you, I can't recall having ever changed the batts since I got the
thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).

It's funny....I've been "into" electronics since I was a little kid, and
actively working in an electronics based field, and up until a year or two
ago, never heard the word "valve" used as a reference to a vacuum tube.

This thread struck my 'funny bone'. Many decades ago I was introduced
to 'valves' by the Brits. If you think about it it is very logical as
the function of a tube is as a 'valve', an electron variable valve. My
introduction to Electronics was with tubes, i.e. before transistors.
Brought back memories.

Fokke Nauta wrote:
On 03/11/2012 23:41, John Williamson wrote:
Fokke Nauta wrote:
On 02/11/2012 23:44, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 22:32:37 +0100, Fokke Nauta wrote:

On 02/11/2012 20:42, Gene E. Bloch wrote:
On Fri, 02 Nov 2012 18:59:39 +0000, Ed Cryer wrote:

Paul wrote:
Ed Cryer wrote:
Drew wrote:
On 11/1/2012 12:04 PM, Ed Cryer wrote:
In our local sports centre swimming pool there's a clock on the
wall. It
keeps good time. I've relied on it for years to time myself.
However, every day at 4-00pm exactly it goes into overdrive,
and sweeps
round covering many hours in a few seconds. Then it resets at
just
after
4-00pm, and continues normally.

I've pointed it out to many fellow swimmers; and they stare in
amazement, raised eyebrows and a dim expression over the facial
features
and say they don't know.

The other day I finally gave in and asked at Reception what it
was all
about. She told me that that was the only clock in the Centre
that did
that, that they weren't interconnected and that she didn't
know why.

My best guess is that it's a radio clock, and it self-adjust
every day
at 4-00pm. But I've googled for "clock speeds up at 4-00pm"
and the
like
and haven't found the answer.

Some one here must have met one of these things. If so then
let me know
more.

Ed

Possible atomic clock of some kind?

I have a strong suspicion you're right here. Everybody else
seems to
have gone for radio-control (I did myself as first guess), but
look
what googling has produced.

It looks just like this;
http://www.walmart.com/ip/14-Analog-...Pearl/13443480



And then take a look at these hits for images on "Analog Atomic
Wall
Clock"; there are zillions.
http://tinyurl.com/bt95lv3

There must be quite a lot of these things in use around the
world. The
write-up says;
Radio-Controlled Atomic Time
Automatically sets to exact time
Accurate to the second
Automatically updates for daylight saving time (on/off
option)
4 time zone settings
14'' Plastic Frame
Simple Operation: Insert One AA Alkaline Battery (not
included)
After signal is received, press Time Zone button to set
Four Time Zone Settings
Daylight Saving Time Option On/Off
Manual Reset Button

Ed

According to this, that product uses WWVB.

http://www.lacrosse-clock.com/lacrosse_technology.htm

The signal strength varies through the day. So if it
was having a reception problem, you'd wait until the
signal reached peak strength, to see if the clock could
pick it up.

http://www.nist.gov/pml/div688/grp40/radioclocks.cfm

( http://en.wikipedia.org/wiki/WWVB )

Amazing it runs off one AA alkaline cell. So while
you don't have to set the time, the battery is still
going to need changing.

Paul



I find that hard to believe, too. My little Acctim digital radio
clock
needs two AAs. But it also displays date, temp and phase of moon.
Mind
you, I can't recall having ever changed the batts since I got the
thing.

Ed

Clearly the second battery is for the moon phase :-)

Imagine the battery situation if these things had to use vacuum tubes
(valves).


Well, it would only need 200 batteries to reach the anode voltage.

Fokke

Good one!

In the old days, they made batteries with about 60 cells and used tubes
that needed a B+ (that's engineer's slang for anode voltage) of 90
volts.


Yes!
I used to have a tube handbook with tubes which have a filament
voltage of 1.4 volt and an anode voltage of 90 volts. For battery use!

Wonderful days!

A number of companies made sets using these. I know of at least one that
still works almost as well as the day it was made. The 90V battery used
to last a lot longer than the 1.5 V filament battery. I heard during the
1960s and 1970s of people making replacement mains power supplies for
these sets that fitted into the same space as the batteries.


The anode supply draws only a few milliamps. Filament current was much
more.
But wonderful, if one could develope a power supply that fits in the
battery compartment!

Given the size of these batteries and the power needed, it wasn't
exactly hard, once you could buy diodes with a PRV of over 120 volts.
ISTR the difficult bit was extracting the connectors intact from a dead
battery.


--
Tciao for Now!

John.