measurement
Subject: [time-nuts] Mechanical 1PPS Oscillator Disciplining
From a fascinating (albeit long) article about transatlantic
communication cables
http://archive.wired.com/wired/archive/4.12/ffglass.html
On the bottom of page 45 to the top of page 46
Each piece of equipment
and frequency measurement time-nuts@febo.com
Sent: Friday, January 09, 2015 3:27 PM
Subject: Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining
yes, Ulrich's [ Rohde ] Father made a high precision clock around 1940,
which had an electronically tuned mechanical oscillator. The vibrating
Hi Tom dividing down wasn't always necessary I have sample from the UK GPO
Crystal Factory of NT-cut bars, quartz tuning fork, and Gapped Ring
crystals, the latter marked 400cps (pre Hertz :-)) ) I think these are
post WWII because they are mounted in IO base GT style tube envelopes.
Dividers
Hi
The speed of sound in quartz varies by axis, but only by about 2:1. The same
basic physics that gets you a fundamental 5 MHz crystal that is at thickness Z
gives you some dimension on a 5 KHz crystal that’s close to 1000 * Z. Very low
frequency crystals pretty much have to be designed so
not looked too hard.
Alan
- Original Message -
From: David J Taylor david-tay...@blueyonder.co.uk
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, January 10, 2015 7:06 AM
Subject: Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining
Hi Tom
Similarly, the Tektronix 647 oscilloscope, uses a 4KHz
quartz crystal oscillator, divided by 4 to form its
1KHz calibrator signal. You can hear the crystal
resonate whenever the calibrator is turned on.
The crystal is mounted in an elongated, hermetically
sealed, HC7 style can.
-Chuck Harris
Hi
The mounting points are the standard locations for a flexure bar running the
resonance along it’s length. The sandwich blank is a bit unique.
The normal gate feedback style circuits will get the crystal running. The
impedance will be quite high, so you will need a bit of gain. At low
Hi David yes I think I have seen similar but not as low as that. If you
compare the suspension points the different vibrational mode should
obvious.the suspension point is at a node. I think some of these are
quite difficult to excite, I have not seen any suggested circuits but I have
not
Back in about 1962 I joined a government research lab. My boss had bought a HP
voltmeter (I remember it as being about a yard cubed)
and a HP printer (also a yard cubed) and it printed out on 2 inch wide paper,
like a cash register record.
My boss's problem was that he wanted more precision in
Hi:
You can see the 4 nodes on the Chinese Spouting bowl in my video at:
https://www.youtube.com/watch?v=k68w3OrPztE
When I got it from Cliff Stoll he had recommended using a wet towel to keep the bowl from moving but that damped the
vibrations.
I got 4 stick-on feet and placed them at the
hol...@hotmail.com said:
Basically the solenoid nudged the pendulum
There was an article in Scientific American many years ago. They used a
magnet mounted on the end of a stick attached to the pendulum arm. The arc
of the magnet swung through a hole in the middle of a solenoid coil. A
Many years ago I built a GPSDPO (GPS Disciplined Pendulum Oscillator). A
friend of mine inherited a grandfather clock built in the late 1700's. She
had the movement cleaned and serviced and got the clock working fairly well,
but it was not all that accurate.
I built up a device using a
On 1/10/15 3:08 PM, Hal Murray wrote:
hol...@hotmail.com said:
Basically the solenoid nudged the pendulum
There was an article in Scientific American many years ago. They used a
magnet mounted on the end of a stick attached to the pendulum arm. The arc
of the magnet swung through a hole in
...@febo.com] On Behalf
Of Hal Murray
Sent: Saturday, January 10, 2015 15:09
To: Discussion of precise time and frequency measurement
Cc: hmur...@megapathdsl.net
Subject: Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining
hol...@hotmail.com said:
Basically the solenoid nudged
was not necessary.
Alan
G3NYK
- Original Message -
From: Tom Van Baak t...@leapsecond.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Friday, January 09, 2015 9:51 PM
Subject: Re: [time-nuts] Mechanical 1PPS Oscillator Disciplining
Andy,
Yes, Neal
yes, Ulrich's [ Rohde ] Father made a high precision clock around 1940,
which had an electronically tuned mechanical oscillator. The vibrating
400Hz tuning fork is phase locked to a quartz crystal oscillator, that
was the most precise clock at that time, and it worked as I have seen
it at
In message df7c7705-b1cc-4b8d-8bac-d471e2ab5...@bardagjy.com, Andy Bardagjy w
rites:
Does anyone know any other history about that particular piece of equipment?
I seriously doubt those claims of precision.
At datamuseum.dk we did a small booklet about the history of paper tape
as a
measurement time-nuts@febo.com
Sent: Friday, January 09, 2015 9:22 AM
Subject: [time-nuts] Mechanical 1PPS Oscillator Disciplining
From a fascinating (albeit long) article about transatlantic communication
cables
http://archive.wired.com/wired/archive/4.12/ffglass.html
On the bottom of page 45
From a fascinating (albeit long) article about transatlantic communication
cables
http://archive.wired.com/wired/archive/4.12/ffglass.html
On the bottom of page 45 to the top of page 46
Each piece of equipment on this tabletop is built around a motor that turns
over at the same precise
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