Re: [time-nuts] Antique precision timing device without electronics

2017-03-18 Thread Poul-Henning Kamp 

In message <20170317220437.4a4ff406...@ip-64-139-1-69.sjc.megapath.net>, Hal 
Murray writes:
>
>e...@scace.org said:
>>Frequencies around 15 Hz were common on early 20th century cables,
>> depending on the degree of success in compensating for the inherent
>> capacitance on a cable thousands of miles long surrounded by conductive
>> sea water.
>
>Is the sea water relevant?

Not in a coaxial cable, unless it gets into the cable.

Most telegraph cables where not coaxial and used the sea-water as return path.

>Does enough energy leak through the shield so that it matters?  How well does 
>coax work at low frequencies?

Coax is near perfect at low frequencies, but the lengths of these
cables introduced geophysics as a number of sources of noise.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Bob Bownes 

Don't forget, seawater is the return path...

> On Mar 17, 2017, at 18:04, Hal Murray  wrote:
> 
> 
> e...@scace.org said:
>>   Frequencies around 15 Hz were common on early 20th century cables,
>> depending on the degree of success in compensating for the inherent
>> capacitance on a cable thousands of miles long surrounded by conductive
>> sea water.
> 
> Is the sea water relevant?
> 
> Does enough energy leak through the shield so that it matters?  How well does 
> coax work at low frequencies?
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Hal Murray 

e...@scace.org said:
>Frequencies around 15 Hz were common on early 20th century cables,
> depending on the degree of success in compensating for the inherent
> capacitance on a cable thousands of miles long surrounded by conductive
> sea water.

Is the sea water relevant?

Does enough energy leak through the shield so that it matters?  How well does 
coax work at low frequencies?

-- 
These are my opinions.  I hate spam.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without, > electronics

2017-03-17 Thread Alex Pummer 
Professor Dr. Rohde of Rohde %Schwarz designed in the 1940-es one tuning 
fork oscillator for 400Hz which was to one crystal phase locked. The 
company built many exemplars from it.  I have seen one working unit in 1967.


73

KJ6UHN


On 3/17/2017 1:14 PM, Dan Kemppainen wrote:

This is all cool stuff, and neat to read about.

What's the best (Most stable, most accurate, best adev, etc.) tuning 
fork oscillator made?


What the lowest frequency tuning fork oscillator ever built? Was 1Hz 
ever achieved commercially?


Fun stuff for Friday!

Dan



On 3/17/2017 12:00 PM, time-nuts-requ...@febo.com wrote:

Message: 8
Date: Fri, 17 Mar 2017 01:34:39 +0100 (CET)
From: "iov...@inwind.it" <iov...@inwind.it>
To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>
Subject: Re: [time-nuts] Antique precision timing device without
electronics
Message-ID:
<1660573894.5853221489710879161.javamail.ht...@webmail-13.iol.local>
Content-Type: text/plain;charset="UTF-8"

This is mine, used to calibrate some aircraft related equipment:

https://www.flickr.com/photos/103726899@N08/33326340242/in/dateposted-public/ 



and its diagram:

https://www.flickr.com/photos/103726899@N08/33482556075/in/dateposted-public/ 



iov

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without, > electronics

2017-03-17 Thread Poul-Henning Kamp 

In message <338b9eed-8664-3876-afdf-610abc420...@irtelemetrics.com>, Dan 
Kemppainen writes:

>What the lowest frequency tuning fork oscillator ever built? Was 1Hz 
>ever achieved commercially?

Does flagpoles count ?  :-)

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without, > electronics

2017-03-17 Thread Dan Kemppainen 

This is all cool stuff, and neat to read about.

What's the best (Most stable, most accurate, best adev, etc.) tuning 
fork oscillator made?


What the lowest frequency tuning fork oscillator ever built? Was 1Hz 
ever achieved commercially?


Fun stuff for Friday!

Dan



On 3/17/2017 12:00 PM, time-nuts-requ...@febo.com wrote:

Message: 8
Date: Fri, 17 Mar 2017 01:34:39 +0100 (CET)
From: "iov...@inwind.it" <iov...@inwind.it>
To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>
Subject: Re: [time-nuts] Antique precision timing device without
electronics
Message-ID:
<1660573894.5853221489710879161.javamail.ht...@webmail-13.iol.local>
Content-Type: text/plain;charset="UTF-8"

This is mine, used to calibrate some aircraft related equipment:

https://www.flickr.com/photos/103726899@N08/33326340242/in/dateposted-public/

and its diagram:

https://www.flickr.com/photos/103726899@N08/33482556075/in/dateposted-public/

iov

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread William H. Fite 
My great, great uncle, longtime design engineer for Guglielmo Marconi had a
tuning fork arrangement of the type discussed here that was enclosed in an
evacuated glass cylinder. I have no idea for what purpose it was used or
what happened to it when he died.


On Friday, March 17, 2017, Poul-Henning Kamp  wrote:

> 
> In message <160EF818076B4D03A0C067ED273D980B@system072>, "Bill Hawkins"
> writes:
>
> >Conservation of power says some must be taken from the fork to operate
> >the contacts.
>
> Electromagnetic induction could give plenty energy for that, given the
> size and heft of the tuning fork.
>
> --
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
> ___
> time-nuts mailing list -- time-nuts@febo.com 
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>


-- 
William H Fite, PhD
Independent Consultant
Statistical Analysis & Research Methods
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Poul-Henning Kamp 

In message , Eric Scace writes:

>   Frequencies around 15 Hz were common on early 20th century cables, 
>depending on the degree of success in compensating for the inherent 
>capacitance on a cable thousands of miles long surrounded by conductive 
>sea water. Cable compensation is an entirely separate subject outside 
>the scope of a time-nuts forum.

In 1924 a new "continuously loaded" submarine cable from New York
to Azores did indeed provide the expected transmission rate 1920
letters per minute:

https://archive.org/details/bstj4-3-355

It seems that people didn't really expect that, because it took a
couple of years to build terminal equipment which could exploit all
that bandwidth:

https://archive.org/details/bstj7-2-225

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Tim Shoppa 
Morris's figure of "taking over a minute to stop oscillating" at 25Hz,
implies a Q in the ballpark of 25*60, or Q>1500, which is quite good for a
tuning fork in air (usually quoted around 1000).

Tim N3QE



On Thu, Mar 16, 2017 at 2:04 PM, Bill Hawkins <bill.i...@pobox.com> wrote:

> Hi Morris,
>
> If there's no active devices (and you'd be sure to see them, not solid
> state) where does the power to operate the motor come from? Is it the
> same contacts that drive the fork?
>
> It's amazing that there is high Q when contacts must be operated by the
> fork.
>
> Did it come with instructions for setting the weights at the end of the
> fork tines?
>
> Best regards,
> Bill Hawkins
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Morris
> Odell
> Sent: Thursday, March 16, 2017 4:23 AM
> To: time-nuts@febo.com
> Subject: [time-nuts] Antique precision timing device without electronics
>
> Hi all,
>
> I was recently asked to resurrect this interesting device by a colleague
> who collects antique scientific instruments. It's a "Chronoscope" made
> by the H. Tinsley company in London in the early 20th century and used
> to measure time intervals with the precision of those days. It's large
> and heavy in a polished wooden case with a top deck that hinges up to
> reveal the innards.
>
> The timing reference is a large tuning fork about 30 cm (1 foot) long
> and running at 25 cps. It's normally in a glass fronted housing (removed
> for the video) that includes a pair of hinged mechanical arms for
> starting it. It's maintained in oscillation by an electromagnet and
> contact arrangement powered from a 12V DC supply. The fork amplitude is
> controlled by a rheostat - too much and the tines impact on the magnet.
> The video frame rate makes the fork look slower than it actually is. I
> was able to extract a signal and measure the frequency with a modern GPS
> disciplined counter - it's 0.007% off its specified 25 Hz! The frequency
> is too low for my HP 5372A so I was not able to easily get an idea of
> stability or do an ADEV measurement. The fork has quite a high Q and
> takes over a minute to stop oscillating after the power is turned off.
> There's a built in higher voltage AC power supply, probably a mains
> transformer, potted in beeswax in a polished wooden box inside that is
> intended to
>   energise a large neon strobe lamp used to adjust the fork.
> Unfortunately the lamp was not with the unit and is no doubt
> irreplaceable.
>
> The 25 Hz signal is filtered by an LC network  and used to run a
> synchronous motor in the Chronoscope unit. Synchronous motors not being
> self-starting, you need to tweak a knob to get it going - there's a joke
> in there but I can't for the life of me think what it could be ?? The
> "Contact" switch and associated socket on the back controls an
> electromagnetic clutch that connects the clockwork counter mechanism to
> the motor and the contact "on" time is indicated on the dials with 10 mS
> resolution.
>
> There's not a single active device in there and after a clean and lube
> it runs very nicely from a modern 12V DC plugpack. My friend is very
> pleased with it and it will take pride of place in his collection.
>
> I'd be interested to know if any time nuts have knowledge or experience
> of this lovely instrument.
>
> A video of it is at  https://youtu.be/i5S8WS9iN_E
>
> Enjoy!
>
> Morris
>
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Poul-Henning Kamp 

In message <160EF818076B4D03A0C067ED273D980B@system072>, "Bill Hawkins" writes:

>Conservation of power says some must be taken from the fork to operate
>the contacts.

Electromagnetic induction could give plenty energy for that, given the
size and heft of the tuning fork.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Eric Scace 
   On British submarine telegraph cable systems, repeater stations and 
receiving sites employed tuning forks. Repeater sites were at cable traffic 
junctions or islands; e.g., Ascension and St Helena Islands in the Atlantic, 
Cocos Keeling in the Indian Ocean, Norfolk Island (junction) and Fanning 
(repeater) in the Pacific.

   The purpose of the tuning fork was to govern transmitted symbol rates for 
outgoing traffic. “Cable code” is a bipolar form of international telegraph 
code (almost exclusively what one hears on the radio today), where both the 
“dot” and “dash” elements have equal duration.

   Equal-duration dots and dashes saved time, meaning more revenue-generating 
traffic could be sent. This was especially important when cables had no 
compensation, and the transmission rates were extremely slow due to large cable 
capacitance.

   Dots and dashes in cable code are instead distinguished by their polarity. 
Alternating dot-dash sequences, when they occurred, created polarity reversals 
on the cable used to recover the best point for pulse sampling.

   When no telegrams were being sent, an idling polarity-reversal sequence was 
periodically injected into the cable (every 15-20 seconds or so) to maintain 
pulse detection synchronization with the distant receiver.

   The tuning fork rate was governed by a Synchronome master clock (and its 
backup). An implementation of electro-mechanical frequency control (EMFC?) 
employed a stepper relay to move the weights on the fork by small amounts to 
maintain frequency synchronization with the Synchronome. Here’s one surviving 
system, the master clock and tuning fork for PK 
 (Porth Curno), the 
landing point in Cornwall England used for most of the Empire’s submarine 
telegraph cables networks (and for many optical fiber cables today). The 
Submarine Telegraph Museum (originally established by Cable & Wireless) on this 
site is a fascinating visit.

   Frequencies around 15 Hz were common on early 20th century cables, depending 
on the degree of success in compensating for the inherent capacitance on a 
cable thousands of miles long surrounded by conductive sea water. Cable 
compensation is an entirely separate subject outside the scope of a time-nuts 
forum.

   Basically, every function we see today in fiber optic or electrical 
synchronous transmission systems (timing, encoding, transmission, pulse 
regeneration, reception, decoding, printing) was invented in electro-mechanical 
form for submarine telegraphy — and realized in beautiful brass & mahogany 
machinery.


signature.asc
Description: Message signed with OpenPGP
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-17 Thread Bill Hawkins 
There is a power amplifier that was available at the time. It's called a
relay.
It would probably take two or three stages to get enough power to drive
the motor.
Were there any relays in the box?

Conservation of power says some must be taken from the fork to operate
the contacts.
This would reduce the Q, but only while the fork was touching the
contacts.
When the battery is switched off, amplitude would decay until the
contacts were no longer touched.
Then you'd get over a minute for it to stop.

At least, that's how it looks to this mechanical engineer.

Bill Hawkins

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill
Hawkins
Sent: Thursday, March 16, 2017 1:05 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Antique precision timing device without
electronics

Hi Morris,

If there's no active devices (and you'd be sure to see them, not solid
state) where does the power to operate the motor come from? Is it the
same contacts that drive the fork?

It's amazing that there is high Q when contacts must be operated by the
fork.

Did it come with instructions for setting the weights at the end of the
fork tines?

Best regards,
Bill Hawkins 

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Morris
Odell
Sent: Thursday, March 16, 2017 4:23 AM
To: time-nuts@febo.com
Subject: [time-nuts] Antique precision timing device without electronics

Hi all,

I was recently asked to resurrect this interesting device by a colleague
who collects antique scientific instruments. It's a "Chronoscope" made
by the H. Tinsley company in London in the early 20th century and used
to measure time intervals with the precision of those days. It's large
and heavy in a polished wooden case with a top deck that hinges up to
reveal the innards. 

The timing reference is a large tuning fork about 30 cm (1 foot) long
and running at 25 cps. It's normally in a glass fronted housing (removed
for the video) that includes a pair of hinged mechanical arms for
starting it. It's maintained in oscillation by an electromagnet and
contact arrangement powered from a 12V DC supply. The fork amplitude is
controlled by a rheostat - too much and the tines impact on the magnet.
The video frame rate makes the fork look slower than it actually is. I
was able to extract a signal and measure the frequency with a modern GPS
disciplined counter - it's 0.007% off its specified 25 Hz! The frequency
is too low for my HP 5372A so I was not able to easily get an idea of
stability or do an ADEV measurement. The fork has quite a high Q and
takes over a minute to stop oscillating after the power is turned off.
There's a built in higher voltage AC power supply, probably a mains
transformer, potted in beeswax in a polished wooden box inside that is
intended to
  energise a large neon strobe lamp used to adjust the fork.
Unfortunately the lamp was not with the unit and is no doubt
irreplaceable. 

The 25 Hz signal is filtered by an LC network  and used to run a
synchronous motor in the Chronoscope unit. Synchronous motors not being
self-starting, you need to tweak a knob to get it going - there's a joke
in there but I can't for the life of me think what it could be ?? The
"Contact" switch and associated socket on the back controls an
electromagnetic clutch that connects the clockwork counter mechanism to
the motor and the contact "on" time is indicated on the dials with 10 mS
resolution. 

There's not a single active device in there and after a clean and lube
it runs very nicely from a modern 12V DC plugpack. My friend is very
pleased with it and it will take pride of place in his collection. 

I'd be interested to know if any time nuts have knowledge or experience
of this lovely instrument.

A video of it is at  https://youtu.be/i5S8WS9iN_E

Enjoy!

Morris

___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-16 Thread iovane--- via time-nuts 
This is mine, used to calibrate some aircraft related equipment:

https://www.flickr.com/photos/103726899@N08/33326340242/in/dateposted-public/ 

and its diagram:

https://www.flickr.com/photos/103726899@N08/33482556075/in/dateposted-public/

iov


>Messaggio originale
>Da: "Mike Seguin" <n1...@burlingtontelecom.net>
>Data: 16/03/2017 22.33
>A: "Discussion of precise time and frequency measurement"<time-nuts@febo.com>
>Ogg: Re: [time-nuts] Antique precision timing device without electronics
>
>Very interesting use of a tuning fork.
>
>I have only seen this once before. I have the tuning fork used with an 
>Ampex Model 300 reel to reel tape machine. The tuning fork was used as a 
>reference in the power supply that drove the capstan motor for accurate 
>speed.
>
>It's 60 Hz not 25 Hz. It's marked B E Eisenhour. Patent is here:
>
>https://www.google.com/patents/US1880923
>
>Pic is here:
>
>https://www.dropbox.com/s/opmxr521qqkx76r/60%20Hz%20Fork.jpg?dl=0
>
>Mike
>
>On 3/16/2017 2:04 PM, Bill Hawkins wrote:
>> Hi Morris,
>>
>> If there's no active devices (and you'd be sure to see them, not solid
>> state) where does the power to operate the motor come from? Is it the
>> same contacts that drive the fork?
>>
>> It's amazing that there is high Q when contacts must be operated by the
>> fork.
>>
>> Did it come with instructions for setting the weights at the end of the
>> fork tines?
>>
>> Best regards,
>> Bill Hawkins
>>
>> -----Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Morris
>> Odell
>> Sent: Thursday, March 16, 2017 4:23 AM
>> To: time-nuts@febo.com
>> Subject: [time-nuts] Antique precision timing device without electronics
>>
>> Hi all,
>>
>> I was recently asked to resurrect this interesting device by a colleague
>> who collects antique scientific instruments. It's a "Chronoscope" made
>> by the H. Tinsley company in London in the early 20th century and used
>> to measure time intervals with the precision of those days. It's large
>> and heavy in a polished wooden case with a top deck that hinges up to
>> reveal the innards.
>>
>> The timing reference is a large tuning fork about 30 cm (1 foot) long
>> and running at 25 cps. It's normally in a glass fronted housing (removed
>> for the video) that includes a pair of hinged mechanical arms for
>> starting it. It's maintained in oscillation by an electromagnet and
>> contact arrangement powered from a 12V DC supply. The fork amplitude is
>> controlled by a rheostat - too much and the tines impact on the magnet.
>> The video frame rate makes the fork look slower than it actually is. I
>> was able to extract a signal and measure the frequency with a modern GPS
>> disciplined counter - it's 0.007% off its specified 25 Hz! The frequency
>> is too low for my HP 5372A so I was not able to easily get an idea of
>> stability or do an ADEV measurement. The fork has quite a high Q and
>> takes over a minute to stop oscillating after the power is turned off.
>> There's a built in higher voltage AC power supply, probably a mains
>> transformer, potted in beeswax in a polished wooden box inside that is
>> intended to
>>   energise a large neon strobe lamp used to adjust the fork.
>> Unfortunately the lamp was not with the unit and is no doubt
>> irreplaceable.
>>
>> The 25 Hz signal is filtered by an LC network  and used to run a
>> synchronous motor in the Chronoscope unit. Synchronous motors not being
>> self-starting, you need to tweak a knob to get it going - there's a joke
>> in there but I can't for the life of me think what it could be ?? The
>> "Contact" switch and associated socket on the back controls an
>> electromagnetic clutch that connects the clockwork counter mechanism to
>> the motor and the contact "on" time is indicated on the dials with 10 mS
>> resolution.
>>
>> There's not a single active device in there and after a clean and lube
>> it runs very nicely from a modern 12V DC plugpack. My friend is very
>> pleased with it and it will take pride of place in his collection.
>>
>> I'd be interested to know if any time nuts have knowledge or experience
>> of this lovely instrument.
>>
>> A video of it is at  https://youtu.be/i5S8WS9iN_E
>>
>> Enjoy!
>>
>> Morris
>>
>>

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-16 Thread David 
I think Bob Pease of National Semiconductor fame mentioned looking for
the earliest use of phase locked loops and finding a reference to a
European clock maker who had a master pendulum clock with a mechanical
coupling that phase locked newly built clocks when left connected
overnight.

On Thu, 16 Mar 2017 20:22:42 +1100, you wrote:

>Hi all,
>
>I was recently asked to resurrect this interesting device by a colleague who 
>collects antique scientific instruments. It’s a "Chronoscope" made by the H. 
>Tinsley company in London in the early 20th century and used to measure time 
>intervals with the precision of those days. It's large and heavy in a polished 
>wooden case with a top deck that hinges up to reveal the innards. 
>
>The timing reference is a large tuning fork about 30 cm (1 foot) long and 
>running at 25 cps. It's normally in a glass fronted housing (removed for the 
>video) that includes a pair of hinged mechanical arms for starting it. It's 
>maintained in oscillation by an electromagnet and contact arrangement powered 
>from a 12V DC supply. The fork amplitude is controlled by a rheostat - too 
>much and the tines impact on the magnet. The video frame rate makes the fork 
>look slower than it actually is. I was able to extract a signal and measure 
>the frequency with a modern GPS disciplined counter - it's 0.007% off its 
>specified 25 Hz! The frequency is too low for my HP 5372A so I was not able to 
>easily get an idea of stability or do an ADEV measurement. The fork has quite 
>a high Q and takes over a minute to stop oscillating after the power is turned 
>off. There's a built in higher voltage AC power supply, probably a mains 
>transformer, potted in beeswax in a polished wooden box inside that is 
>intended t
 o
>  energise a large neon strobe lamp used to adjust the fork. Unfortunately the 
> lamp was not with the unit and is no doubt irreplaceable. 
>
>The 25 Hz signal is filtered by an LC network  and used to run a synchronous 
>motor in the Chronoscope unit. Synchronous motors not being self-starting, you 
>need to tweak a knob to get it going - there's a joke in there but I can't for 
>the life of me think what it could be ? The "Contact" switch and associated 
>socket on the back controls an electromagnetic clutch that connects the 
>clockwork counter mechanism to the motor and the contact "on" time is 
>indicated on the dials with 10 mS resolution. 
>
>There's not a single active device in there and after a clean and lube it runs 
>very nicely from a modern 12V DC plugpack. My friend is very pleased with it 
>and it will take pride of place in his collection. 
>
>I'd be interested to know if any time nuts have knowledge or experience of 
>this lovely instrument.
>
>A video of it is at  https://youtu.be/i5S8WS9iN_E
>
>Enjoy!
>
>Morris
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-16 Thread Mike Seguin 

Very interesting use of a tuning fork.

I have only seen this once before. I have the tuning fork used with an 
Ampex Model 300 reel to reel tape machine. The tuning fork was used as a 
reference in the power supply that drove the capstan motor for accurate 
speed.


It's 60 Hz not 25 Hz. It's marked B E Eisenhour. Patent is here:

https://www.google.com/patents/US1880923

Pic is here:

https://www.dropbox.com/s/opmxr521qqkx76r/60%20Hz%20Fork.jpg?dl=0

Mike

On 3/16/2017 2:04 PM, Bill Hawkins wrote:

Hi Morris,

If there's no active devices (and you'd be sure to see them, not solid
state) where does the power to operate the motor come from? Is it the
same contacts that drive the fork?

It's amazing that there is high Q when contacts must be operated by the
fork.

Did it come with instructions for setting the weights at the end of the
fork tines?

Best regards,
Bill Hawkins

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Morris
Odell
Sent: Thursday, March 16, 2017 4:23 AM
To: time-nuts@febo.com
Subject: [time-nuts] Antique precision timing device without electronics

Hi all,

I was recently asked to resurrect this interesting device by a colleague
who collects antique scientific instruments. It's a "Chronoscope" made
by the H. Tinsley company in London in the early 20th century and used
to measure time intervals with the precision of those days. It's large
and heavy in a polished wooden case with a top deck that hinges up to
reveal the innards.

The timing reference is a large tuning fork about 30 cm (1 foot) long
and running at 25 cps. It's normally in a glass fronted housing (removed
for the video) that includes a pair of hinged mechanical arms for
starting it. It's maintained in oscillation by an electromagnet and
contact arrangement powered from a 12V DC supply. The fork amplitude is
controlled by a rheostat - too much and the tines impact on the magnet.
The video frame rate makes the fork look slower than it actually is. I
was able to extract a signal and measure the frequency with a modern GPS
disciplined counter - it's 0.007% off its specified 25 Hz! The frequency
is too low for my HP 5372A so I was not able to easily get an idea of
stability or do an ADEV measurement. The fork has quite a high Q and
takes over a minute to stop oscillating after the power is turned off.
There's a built in higher voltage AC power supply, probably a mains
transformer, potted in beeswax in a polished wooden box inside that is
intended to
  energise a large neon strobe lamp used to adjust the fork.
Unfortunately the lamp was not with the unit and is no doubt
irreplaceable.

The 25 Hz signal is filtered by an LC network  and used to run a
synchronous motor in the Chronoscope unit. Synchronous motors not being
self-starting, you need to tweak a knob to get it going - there's a joke
in there but I can't for the life of me think what it could be ?? The
"Contact" switch and associated socket on the back controls an
electromagnetic clutch that connects the clockwork counter mechanism to
the motor and the contact "on" time is indicated on the dials with 10 mS
resolution.

There's not a single active device in there and after a clean and lube
it runs very nicely from a modern 12V DC plugpack. My friend is very
pleased with it and it will take pride of place in his collection.

I'd be interested to know if any time nuts have knowledge or experience
of this lovely instrument.

A video of it is at  https://youtu.be/i5S8WS9iN_E

Enjoy!

Morris

___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



--

73,
Mike, N1JEZ
"A closed mouth gathers no feet"
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Antique precision timing device without electronics

2017-03-16 Thread cdelect 
Very cool!

Thanks for sharing.

You could probably use any of the large vintage neon bulbs to replace the
missing lamp.

Cheers,

Corby

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-16 Thread Scott McGrath 
For the bulb you can probably replace it with a W1A or AR-1bulb which is an 
argon bulb commonly used in old school contact printers they have a purple hue 
and also emit long wave UV light   

I doubt if they are still manufactured but a photo shop or studio or chemist 
shop which developed film which has been in business a long time 60's and 70' 
is likely to have some as they were very common them

Content by Scott
Typos by Siri

> On Mar 16, 2017, at 5:22 AM, Morris Odell  wrote:
> 
> Hi all,
> 
> I was recently asked to resurrect this interesting device by a colleague who 
> collects antique scientific instruments. It’s a "Chronoscope" made by the H. 
> Tinsley company in London in the early 20th century and used to measure time 
> intervals with the precision of those days. It's large and heavy in a 
> polished wooden case with a top deck that hinges up to reveal the innards. 
> 
> The timing reference is a large tuning fork about 30 cm (1 foot) long and 
> running at 25 cps. It's normally in a glass fronted housing (removed for the 
> video) that includes a pair of hinged mechanical arms for starting it. It's 
> maintained in oscillation by an electromagnet and contact arrangement powered 
> from a 12V DC supply. The fork amplitude is controlled by a rheostat - too 
> much and the tines impact on the magnet. The video frame rate makes the fork 
> look slower than it actually is. I was able to extract a signal and measure 
> the frequency with a modern GPS disciplined counter - it's 0.007% off its 
> specified 25 Hz! The frequency is too low for my HP 5372A so I was not able 
> to easily get an idea of stability or do an ADEV measurement. The fork has 
> quite a high Q and takes over a minute to stop oscillating after the power is 
> turned off. There's a built in higher voltage AC power supply, probably a 
> mains transformer, potted in beeswax in a polished wooden box inside that is 
> intended 
 to
>  energise a large neon strobe lamp used to adjust the fork. Unfortunately the 
> lamp was not with the unit and is no doubt irreplaceable. 
> 
> The 25 Hz signal is filtered by an LC network  and used to run a synchronous 
> motor in the Chronoscope unit. Synchronous motors not being self-starting, 
> you need to tweak a knob to get it going - there's a joke in there but I 
> can't for the life of me think what it could be  The "Contact" switch and 
> associated socket on the back controls an electromagnetic clutch that 
> connects the clockwork counter mechanism to the motor and the contact "on" 
> time is indicated on the dials with 10 mS resolution. 
> 
> There's not a single active device in there and after a clean and lube it 
> runs very nicely from a modern 12V DC plugpack. My friend is very pleased 
> with it and it will take pride of place in his collection. 
> 
> I'd be interested to know if any time nuts have knowledge or experience of 
> this lovely instrument.
> 
> A video of it is at  https://youtu.be/i5S8WS9iN_E
> 
> Enjoy!
> 
> Morris
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Antique precision timing device without electronics

2017-03-16 Thread Bill Hawkins 
Hi Morris,

If there's no active devices (and you'd be sure to see them, not solid
state) where does the power to operate the motor come from? Is it the
same contacts that drive the fork?

It's amazing that there is high Q when contacts must be operated by the
fork.

Did it come with instructions for setting the weights at the end of the
fork tines?

Best regards,
Bill Hawkins 

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Morris
Odell
Sent: Thursday, March 16, 2017 4:23 AM
To: time-nuts@febo.com
Subject: [time-nuts] Antique precision timing device without electronics

Hi all,

I was recently asked to resurrect this interesting device by a colleague
who collects antique scientific instruments. It's a "Chronoscope" made
by the H. Tinsley company in London in the early 20th century and used
to measure time intervals with the precision of those days. It's large
and heavy in a polished wooden case with a top deck that hinges up to
reveal the innards. 

The timing reference is a large tuning fork about 30 cm (1 foot) long
and running at 25 cps. It's normally in a glass fronted housing (removed
for the video) that includes a pair of hinged mechanical arms for
starting it. It's maintained in oscillation by an electromagnet and
contact arrangement powered from a 12V DC supply. The fork amplitude is
controlled by a rheostat - too much and the tines impact on the magnet.
The video frame rate makes the fork look slower than it actually is. I
was able to extract a signal and measure the frequency with a modern GPS
disciplined counter - it's 0.007% off its specified 25 Hz! The frequency
is too low for my HP 5372A so I was not able to easily get an idea of
stability or do an ADEV measurement. The fork has quite a high Q and
takes over a minute to stop oscillating after the power is turned off.
There's a built in higher voltage AC power supply, probably a mains
transformer, potted in beeswax in a polished wooden box inside that is
intended to
  energise a large neon strobe lamp used to adjust the fork.
Unfortunately the lamp was not with the unit and is no doubt
irreplaceable. 

The 25 Hz signal is filtered by an LC network  and used to run a
synchronous motor in the Chronoscope unit. Synchronous motors not being
self-starting, you need to tweak a knob to get it going - there's a joke
in there but I can't for the life of me think what it could be ?? The
"Contact" switch and associated socket on the back controls an
electromagnetic clutch that connects the clockwork counter mechanism to
the motor and the contact "on" time is indicated on the dials with 10 mS
resolution. 

There's not a single active device in there and after a clean and lube
it runs very nicely from a modern 12V DC plugpack. My friend is very
pleased with it and it will take pride of place in his collection. 

I'd be interested to know if any time nuts have knowledge or experience
of this lovely instrument.

A video of it is at  https://youtu.be/i5S8WS9iN_E

Enjoy!

Morris

___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Antique precision timing device without electronics

2017-03-16 Thread Morris Odell 
Hi all,

I was recently asked to resurrect this interesting device by a colleague who 
collects antique scientific instruments. It’s a "Chronoscope" made by the H. 
Tinsley company in London in the early 20th century and used to measure time 
intervals with the precision of those days. It's large and heavy in a polished 
wooden case with a top deck that hinges up to reveal the innards. 

The timing reference is a large tuning fork about 30 cm (1 foot) long and 
running at 25 cps. It's normally in a glass fronted housing (removed for the 
video) that includes a pair of hinged mechanical arms for starting it. It's 
maintained in oscillation by an electromagnet and contact arrangement powered 
from a 12V DC supply. The fork amplitude is controlled by a rheostat - too much 
and the tines impact on the magnet. The video frame rate makes the fork look 
slower than it actually is. I was able to extract a signal and measure the 
frequency with a modern GPS disciplined counter - it's 0.007% off its specified 
25 Hz! The frequency is too low for my HP 5372A so I was not able to easily get 
an idea of stability or do an ADEV measurement. The fork has quite a high Q and 
takes over a minute to stop oscillating after the power is turned off. There's 
a built in higher voltage AC power supply, probably a mains transformer, potted 
in beeswax in a polished wooden box inside that is intended to
  energise a large neon strobe lamp used to adjust the fork. Unfortunately the 
lamp was not with the unit and is no doubt irreplaceable. 

The 25 Hz signal is filtered by an LC network  and used to run a synchronous 
motor in the Chronoscope unit. Synchronous motors not being self-starting, you 
need to tweak a knob to get it going - there's a joke in there but I can't for 
the life of me think what it could be  The "Contact" switch and associated 
socket on the back controls an electromagnetic clutch that connects the 
clockwork counter mechanism to the motor and the contact "on" time is indicated 
on the dials with 10 mS resolution. 

There's not a single active device in there and after a clean and lube it runs 
very nicely from a modern 12V DC plugpack. My friend is very pleased with it 
and it will take pride of place in his collection. 

I'd be interested to know if any time nuts have knowledge or experience of this 
lovely instrument.

A video of it is at  https://youtu.be/i5S8WS9iN_E

Enjoy!

Morris

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.