[time-nuts] HP 5345A
bill at iaxs.net
Fri Dec 29 23:22:09 EST 2006
I foresee a discussion similar to those of wine connoisseurs.
What is the maison and vintage of the crystal? Was it
found on the upper or lower slope of the hill? Who cut it
and when and how? Is it properly contained?
What do the critics (with finer equipment than mine) say
about the ability of the crystal to age well?
Happy New Year, all. At least, may it start out with a
sustainable level of happiness. But if it doesn't, may
you have some good fortune before the Odometer of Time
clicks off another year, and we get to start over.
(Sorry to introduce a light note into these heavy
discussions. I hope some will appreciate it.)
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Brooke Clarke
Sent: Friday, December 29, 2006 5:21 PM
To: richard at karlquist.com; Discussion of precise time and frequency
Subject: Re: [time-nuts] HP 5345A
Is there a way to know about the type of aging up front. For example
what crystal makers have only micro cracks as the aging mechanism? For
what starting date? My guess is that there are plenty of crystals that
have aging that's mainly due to contamination or other causes that the
better makers have eliminated.
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
Rick Karlquist wrote:
>Hal Murray wrote:
>>I thought aging was generally uni-directional and reasonably
>>predictable if you had enough data.
>>Does it wander in both directions?
>This is probably on the list of the "10 greatest myths about crystal
>oscillators". Many decades ago, there were systematic aging effects
>such as you speak of. I remember learning as a youth that glass
>crystals age up and metal crystals age down.
>Over the years, any such systematic effects have been analyzed one by
>one to understand the root cause, and then the process has been fixed
>to get rid of that aging effect. What we are now left with are tiny
>cracks and crevasses that grow sporadically like a crack in an auto
>windshield. At least that is what we think is going on. The process
>people, like my friends Charles Adams and Jack Kusters, have worked
>themselves out of a job had taken retirement, because, like the
>"efficient stock market"
>theory, there is no predictability to the aging data. It is truly a
>"random walk down Wall Street" or in this case a random walk in time.
>Oscillators will age in one direction for a while but may then age in
>the opposite direction for while for no particular reason. Not only
>that, but crystals will jump a part in 1E^9 or so every so often. I've
>never seen a 10811 crystal without jumps if you wait long enough. I
>don't know of any other crystal makers who claim to not have jumps.
>Rick Karlquist N6RK
>time-nuts mailing list
>time-nuts at febo.com
time-nuts mailing list
time-nuts at febo.com
More information about the time-nuts