webcam app to watch for and time stamp changes
In the watchmaker world, we have error, and personal error.
The watchmaker sets the watch to get the most accurate time
while sitting in his shop, and then he gives the watch to the
customer with the instructions to wear the watch normally for
2 weeks, but don't reset it, and bring it back for adjustment.
The watchmaker carefully checks the time, and makes note of
the error from real time. He then adjusts the watch to run,
at normal shop temperature, to run at -1 times the error...
in other words, if the watch is 2 minutes fast over two weeks,
he adjusts so that it will be 2 minutes slow over two weeks...
at normal shop temperature.
The customer takes his watch, and marvels at how extremely
accurate it is.
The lesson to be learned is set the LCD watch using the counter,
at normal shop temperature. Give it to the customer to wear
for two weeks. Calculate the error rate, and then readjust the
watch for -1 times that error rate at normal shop temperature.
-Chuck Harris (amateur watchmaker)
EB4APL wrote:
When LCD wristwatches became common in the seventies we, in the frequency and timing
group of a space tracking facility, investigated the possibility of adjusting our new
watches against our standard.
We found that a a small copper plate, about 1 X 2 cm, resting against the display and
connected to a scope probe was able to pick up enough 32 KHz energy to be displayed
in the scope. Then connected the vertical output to an HP 5245L counter referenced
to our standard and set the gate time to 10 seconds and got the frequency. We
learned that the watch had to be worn in order to operate at the right temperature,
the body acting as an oven, so you has to wear it backside in order to access the
trimmer (yes, at that time those watches had and adjusting trimmer, maybe heritage
from the mechanical ones, laser trimming arrived later).
Our group became very popular and busy adjusting every watch our colleagues bought to
a few seconds per month.
Ignacio, EB4APL
Wouldn't it be easier to glue a fruit fly to the head of a pin and
attach electrodes to its visual ganglia to detect the change in
intensity of a segment of the display?
Excuse me, just back from surgery and the anesthetic may have
lingering effects. Discussions like this help to pass the time.
Bill Hawkins
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Jim Lux
Sent: Sunday, March 03, 2013 1:10 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] webcam app to watch for and time stamp changes
On 3/3/13 10:47 AM, Chris Albertson wrote:
It's not an e-field antenna. The goal is the sense the current in the
LCD.
My bet is no much of anything leaks out of that RSA device or a wrist
watch either. You have to figure that tiny battery lasts for over a
year and even if ALL the energy in the battery went to making RF you'd
divide the battery energy by the battery life time to get power.
What's have some micro watts at most. Then you figure most of the
bettery power really goes into heat not RF.
detecting femtowatts isn't really an issue for RF.. 1 fW is -120dBm,
which is a "strong" signal in a lot of applications. Typical FM
receivers have sensitivities around 0.2 microvolt into 50ohms, which is
about a femtowatt. -150dBm is getting tougher, but is still 24 dB
above the kTB noise floor in a 1 Hz BW.
However, what we're looking for here is most likely a changing magnetic
field. It's not being "radiated" away, the energy stays in the circuit
(in the near field) for the most part. (question, does putting a RSA
fob in a lossy magnetic medium make the battery go dead faster?)
So the question really comes down to how small a repetitive change in
magnetic field can be detected?
Or if you're using an efield probe, it's sort of the same thing. You're
not concerned about far field radiation, which will be very small (the
"antenna" is a tiny fraction of a wavelength.
Here's a similar thing.. Say you have a twisted pair carrying a signal:
very little radiates away. But if you have a small probe (E or H) you
can put it closer to one wire of the pair than the other, and
(potentially) detect the E or H field from the wire.
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On 3/4/13 6:52 PM, Bill Hawkins wrote:
Wouldn't it be easier to glue a fruit fly to the head of a pin and
attach electrodes to its visual ganglia to detect the change in
intensity of a segment of the display?
Excuse me, just back from surgery and the anesthetic may have
lingering effects. Discussions like this help to pass the time.
I think you'd have to separately calibrate the fruit fly's optic nerve
to remove the effect. A quick google doesn't seem to find any published
information on the Allan deviation of the propagation through the system.
Do so and publishing the result would certainly confirm some folks
opinion about the "nut" part of time-nuts.
(I did find data on nerve propagation in general )
On 03/05/2013 03:10 PM, Jim Lux wrote:
On 3/4/13 6:52 PM, Bill Hawkins wrote:
Wouldn't it be easier to glue a fruit fly to the head of a pin and
attach electrodes to its visual ganglia to detect the change in
intensity of a segment of the display?
Excuse me, just back from surgery and the anesthetic may have
lingering effects. Discussions like this help to pass the time.
I think you'd have to separately calibrate the fruit fly's optic nerve
to remove the effect. A quick google doesn't seem to find any published
information on the Allan deviation of the propagation through the system.
Do so and publishing the result would certainly confirm some folks
opinion about the "nut" part of time-nuts.
(I did find data on nerve propagation in general )
You would be a good candidate for the ig-Noble price if you published
it, possibly if you can show some really good reason for it, beyond the
stability measurements of RSA devices.
In order to get invited to this town, the Nobel comittees has a bit
different ruleset.
Cheers,
Magnus
HP 5 MHz Source
HP00105-6012 Crystal Oven Assy Series 1144A
- 20 V line shorted to ground internally
Too lazy to go inside to fix; You want, it's yours
Lester B Veenstra MØYCM K1YCM W8YCM
lester@veenstras.com
US Postal Address:
5 Shrine Club Drive
HC84 Box 89C
Keyser WV 26726
GPS: 39.33675 N 78.9823527 W
Telephones:
Home: +1-304-289-6057 US cell
+1-304-790-9192 UK cell +44-(0)7849-248-749
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Gone to a good home
Lester B Veenstra MØYCM K1YCM W8YCM
lester@veenstras.com
US Postal Address:
5 Shrine Club Drive
HC84 Box 89C
Keyser WV 26726
GPS: 39.33675 N 78.9823527 W
Telephones:
Home: +1-304-289-6057
US cell +1-304-790-9192
UK cell +44-(0)7849-248-749
Guam Cell: +1-671-929-8141
Jamaica: +1-876-456-8898
This e-mail and any documents attached hereto contain confidential or
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-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Lester Veenstra
Sent: Tuesday, March 05, 2013 9:47 PM
To: time-nuts@febo.com
Subject: [time-nuts] Free to a good home
HP 5 MHz Source
HP00105-6012 Crystal Oven Assy Series 1144A
- 20 V line shorted to ground internally
Too lazy to go inside to fix; You want, it's yours
Lester B Veenstra MØYCM K1YCM W8YCM
lester@veenstras.com
US Postal Address:
5 Shrine Club Drive
HC84 Box 89C
Keyser WV 26726
GPS: 39.33675 N 78.9823527 W
Telephones:
Home: +1-304-289-6057 US cell
+1-304-790-9192 UK cell +44-(0)7849-248-749
Guam Cell: +1-671-929-8141
Jamaica: +1-876-456-8898
This e-mail and any documents attached hereto contain confidential or
privileged information. The information is intended to be for use only by
the individual or entity to whom they are addressed. If you are not the
intended recipient or the person responsible for delivering the e-mail to
the intended recipient, be aware that any disclosure, copying, distribution
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I would be interested
Paul
Wb8tsl
On Tue, Mar 5, 2013 at 9:47 PM, Lester Veenstra lester@veenstras.comwrote:
HP 5 MHz Source
HP00105-6012 Crystal Oven Assy Series 1144A
- 20 V line shorted to ground internally
Too lazy to go inside to fix; You want, it's yours
Lester B Veenstra MØYCM K1YCM W8YCM
lester@veenstras.com
US Postal Address:
5 Shrine Club Drive
HC84 Box 89C
Keyser WV 26726
GPS: 39.33675 N 78.9823527 W
Telephones:
Home: +1-304-289-6057 US cell
+1-304-790-9192 UK cell +44-(0)7849-248-749
Guam Cell: +1-671-929-8141
Jamaica: +1-876-456-8898
This e-mail and any documents attached hereto contain confidential or
privileged information. The information is intended to be for use only by
the individual or entity to whom they are addressed. If you are not the
intended recipient or the person responsible for delivering the e-mail to
the intended recipient, be aware that any disclosure, copying, distribution
or use of the contents of this e-mail or any documents attached hereto is
prohibited.
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