I think I've become a Volt nut too.
Hi All,
I have been a time nut for some time now. I think I've become a Volt nut
too! I build the Silicon Chip magazine Voltage reference late last year but
didn't have anything to compare it against so I bought a Fluke 732A DC
reference standard.
I there a group I can subscribe to that can help me with this?
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
Regards,
Nic
VK2KXN VK5ZAT
Ah, but a man with 14 standards can use statistics!
Sorry.
Bill Hawkins
-----Original Message-----
From: Nic McLean
Sent: Monday, January 11, 2010 9:12 PM
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
Ah, but it is possible that all 14 could be off in the same
direction.
Sorry.
Bill Hawkins wrote:
Ah, but a man with 14 standards can use statistics!
Sorry.
Bill Hawkins
-----Original Message-----
From: Nic McLean
Sent: Monday, January 11, 2010 9:12 PM
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
But if you had 1000 references, or maybe 100,000, the law of large numbers would be on your side =)
Sent via BlackBerry by AT&T
-----Original Message-----
From: Mike Naruta AA8K aa8k@comcast.net
Date: Mon, 11 Jan 2010 22:24:30
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Subject: Re: [time-nuts] I think I've become a Volt nut too.
Ah, but it is possible that all 14 could be off in the same
direction.
Sorry.
Bill Hawkins wrote:
Ah, but a man with 14 standards can use statistics!
Sorry.
Bill Hawkins
-----Original Message-----
From: Nic McLean
Sent: Monday, January 11, 2010 9:12 PM
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
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.
True, but there is always a probability that they all happen to
be off one way.
Quite a small probability, but not impossible.
Sorry for the disturbing thought.
:)
john.foege@gmail.com wrote:
But if you had 1000 references, or maybe 100,000, the law of large numbers would be on your side =)
Sent via BlackBerry by AT&T
-----Original Message-----
From: Mike Naruta AA8K aa8k@comcast.net
Date: Mon, 11 Jan 2010 22:24:30
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Subject: Re: [time-nuts] I think I've become a Volt nut too.
Ah, but it is possible that all 14 could be off in the same
direction.
Sorry.
Bill Hawkins wrote:
Ah, but a man with 14 standards can use statistics!
Sorry.
Bill Hawkins
-----Original Message-----
From: Nic McLean
Sent: Monday, January 11, 2010 9:12 PM
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
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.
Google 'Volt Nuts'. Then continue to the website.
Joe
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Nic McLean
Sent: Monday, January 11, 2010 9:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: [time-nuts] I think I've become a Volt nut too.
Hi All,
I have been a time nut for some time now. I think I've become a Volt nut
too! I build the Silicon Chip magazine Voltage reference late last year but
didn't have anything to compare it against so I bought a Fluke 732A DC
reference standard.
I there a group I can subscribe to that can help me with this?
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
Regards,
Nic
VK2KXN VK5ZAT
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.
That will only be true of primary standards. Secondary standards
must be calibrated to some "primary standard". If all 100,000 of
your secondary standards were calibrated to the wrong value, they
will all have values that hover around that wrong value.
-Chuck Harris
john.foege@gmail.com wrote:
But if you had 1000 references, or maybe 100,000, the law of large numbers would be on your side =)
Sent via BlackBerry by AT&T
-----Original Message-----
From: Mike Naruta AA8K aa8k@comcast.net
Date: Mon, 11 Jan 2010 22:24:30
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Subject: Re: [time-nuts] I think I've become a Volt nut too.
Ah, but it is possible that all 14 could be off in the same
direction.
Sorry.
No. You've already fallen in the rabbit hole.. The next thing is to begin
your study of randomness.
HeHeHeHe...
Don
----- Original Message -----
From: "Nic McLean" mcleann@bigpond.com
To: "'Discussion of precise time and frequency measurement'"
time-nuts@febo.com
Sent: Monday, January 11, 2010 8:12 PM
Subject: [time-nuts] I think I've become a Volt nut too.
Hi All,
I have been a time nut for some time now. I think I've become a Volt nut
too! I build the Silicon Chip magazine Voltage reference late last year
but
didn't have anything to compare it against so I bought a Fluke 732A DC
reference standard.
I there a group I can subscribe to that can help me with this?
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
Regards,
Nic
VK2KXN VK5ZAT
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.
Hi Nick
Is it possible to let us have the schematic/details of this SC Magazine
Voltage Reference project, thanks
Roy
From: "Nic McLean" mcleann@bigpond.com
Sent: Tuesday, January 12, 2010 3:12 AM
To: "'Discussion of precise time and frequency measurement'"
time-nuts@febo.com
Subject: [time-nuts] I think I've become a Volt nut too.
Hi All,
I have been a time nut for some time now. I think I've become a Volt nut
too! I build the Silicon Chip magazine Voltage reference late last year
but
didn't have anything to compare it against so I bought a Fluke 732A DC
reference standard.
I there a group I can subscribe to that can help me with this?
Can I coin the phrase; A man that has one DC Voltage standard knows how
accurate his meter is, whereas a man with two standards is not quite sure!
Regards,
Nic
VK2KXN VK5ZAT
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.
Sure Chuck. What I was talking about was a part of statistics
that we in our gnat-hair-splitting compulsive group may forget
about.
Let's assume that our 100,000 standards were carefully
calibrated against THE standard. There is a small amount of
error in the calibration process. Let us even assume that the
error in the calibration process is normally distributed.
It is not impossible that for a sample of 100,000 secondary
standards, that the errors would be all be off in the same
direction, compared to the standard's value.
Now, granted, this would be a small probability indeed. But it
is possible to toss a coin fifty times and have fifty "heads".
The smart bet is that it won't.
Chuck Harris wrote:
That will only be true of primary standards. Secondary standards
must be calibrated to some "primary standard". If all 100,000 of
your secondary standards were calibrated to the wrong value, they
will all have values that hover around that wrong value.
-Chuck Harris
It is possible for 100k secondary standards average to be skewed if they were calibrated to the same primary standard. All the primary standards would have to different for the secondary average to be an real average.
Coin toss analogy would be slightly different if the coins were all different shapes and sizes.. but probably not!
It is not impossible that for a sample of 100,000 secondary standards, that the errors would be all be off in the same direction, compared to the standard's value.
Now, granted, this would be a small probability indeed. But it is possible to toss a coin fifty times and have fifty "heads". The smart bet is that it won't.
--
Raj, VU2ZAP
Bangalore, India.
Roy,
The standard is based on the Analog Devices AD588 chip.
http://www.analog.com/static/imported-files/data_sheets/AD588.pdf
You can buy the magazine article at
http://siliconchip.com.au/cms/A_111365/article.html
Regards,
Nic
Hi Nick
Is it possible to let us have the schematic/details of this SC Magazine
Voltage Reference project, thanks
Roy
Wow thats a nice chip indeed
On Tue, Jan 12, 2010 at 2:58 PM, Nic McLean mcleann@bigpond.com wrote:
Roy,
The standard is based on the Analog Devices AD588 chip.
http://www.analog.com/static/imported-files/data_sheets/AD588.pdf
You can buy the magazine article at
http://siliconchip.com.au/cms/A_111365/article.html
Regards,
Nic
Hi Nick
Is it possible to let us have the schematic/details of this SC Magazine
Voltage Reference project, thanks
Roy
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.
Were you guys around (about a year back, I think) when this reference
was mentioned?
http://www.voltagestandard.com/
Seems like excellent price/performance to me. I see he has a more
accurate, more expensive model too.
paul swed wrote:
Wow thats a nice chip indeed
On Tue, Jan 12, 2010 at 2:58 PM, Nic McLean mcleann@bigpond.com wrote:
Roy,
The standard is based on the Analog Devices AD588 chip.
http://www.analog.com/static/imported-files/data_sheets/AD588.pdf
You can buy the magazine article at
http://siliconchip.com.au/cms/A_111365/article.html
Regards,
Nic
Hi Nick
Is it possible to let us have the schematic/details of this SC Magazine
Voltage Reference project, thanks
Roy
Mike Naruta AA8K wrote:
Sure Chuck. What I was talking about was a part of statistics that we
in our gnat-hair-splitting compulsive group may forget about.
Let's assume that our 100,000 standards were carefully calibrated
against THE standard. There is a small amount of error in the
calibration process. Let us even assume that the error in the
calibration process is normally distributed.
It is not impossible that for a sample of 100,000 secondary standards,
that the errors would be all be off in the same direction, compared to
the standard's value.
Now, granted, this would be a small probability indeed. But it is
possible to toss a coin fifty times and have fifty "heads". The smart
bet is that it won't.
Well, if the distribution of these is only random and of benign
randomness like gaussian noise.
If you have an aging mechanism for instance, over time this huge set
would drift in that direction and that would produce a moving average
value...
The rate of calibration to a primary standard would be one of the
parameters needed to set the limit of drift.
So, systematic drift is not canceled by large number statistics. It just
doest not obey the underlying assumption. Long-term noise of clocks
obery the f^-3 noise which does not converge nicely and statistical
measures needs to be adapted to provide reasnoble measures. This is why
we have ADEV and friends.
Again, this is why you need to separate stability with reproducability
aspects.
Cheers,
Magnus