"Thanks Andrew, now I see it has a rubidium clock, it does not say, but it likely has a double-oven OCXO?"
Not sure about a double OCXO; one would seem to be enough?
A GPS-disciplined rubidium atomic clock just locks to GPS as long as the GPS signal is available. When it isn't, then the OCXO "freewheels" locked to the slightly less-accurate rubidium physics package.
GPS is more accurate than the rubidium standard as the atomic clocks aboard the GPS sats are is disciplined to the 450 atomic clocks governing TAI - International Atomic Time (the time behind UTC).
Also having two OCXOS would cause confusion, as you already found out. :-)
See: WIKIPEDIA - Rubidium standard
https://en.wikipedia.org/wiki/Rubidium_standard
And thanks for helping me get educated a little, there is a lot that is hidden about these things
You're welcome! Time metrology is a lot of fun. You might enjoy the story of this dad taking his
kids and 3 atomic clocks up a mountain for a weekend to measure relativistic time dilation whne
he got back home and measured the 3 clocks agains his other 20+ atomic clocks in his basement.
I'M LATE BY about 15000.01010101017 seconds, and I wonder how long it will take to get to you?
General and Special relativity means being early or late depends on which timeframe you're using.
State of the art timekeeping these days means 18 or 19 reliable significant figures (mankind's most
precise measurement made ever) are available for measuring time with an error of substantially less
than half a second in "all of time", meaning in all the time elapsed since time began with the Big Bang
13.7 billion years ago (specifically the error is one second every 34 billion years). Excitation frequency is 1,121,015,393,207,857.4 Hz (1.12 PetaHz) thanks to a UV laser.
This level of precision means you can measure time slippage down to a height difference of only
2 cm, i.e. on each side of a piece of toast lying on your plate. See:
WIKIPEDIA - Quantum Logic Clock
https://en.wikipedia.org/wiki/Quantum_logic_clock
The proble with such a clock is your cleaning lady moves it from one side of the table to the other
and by doing so thanks to relativity, poof! there goes your time standard.
Now if I could only get a round doit and sync my Heathkit SB-104A to my atomic clock...
73 de Andrew/N5ASE
On Mon, Aug 4, 2025 at 6:56 PM don Root via groups.io <drootofallevil=teksavvy.com@groups.io> wrote:Thanks Andrew, now I see it has a rubidium clock, it does not say, but it likely has a double-oven OCXO?
And thanks for helping me get educated a little, there is a lot that is hidden about these things
I'M LATE BY about 15000.01010101017 seconds, and I wonder how long it will take to get to you?
From: Amateur-repairs@groups.io [mailto:Amateur-repairs@groups.io] On Behalf Of jahman via groups.io
Sent: Monday, August 4, 2025 1:40 PM
To: Amateur-repairs@groups.io
Subject: Re: [Amateur-repairs] Calibrating test equipment?
Dang! Sorry about that!
This is the one I have and it does sport a rubidium "physics package" inside:
73 de Andrew/N5ASE
On Mon, Aug 4, 2025 at 10:20 AM don Root via groups.io <drootofallevil=teksavvy.com@groups.io> wrote:
Andrew, that seems to be a GPS disciplined crystal, but I'm a learner of this stuff.
From: Amateur-repairs@groups.io [mailto:Amateur-repairs@groups.io] On Behalf Of jahman via groups.io
Sent: Monday, August 4, 2025 6:59 AM
To: Amateur-repairs@groups.io
Subject: Re: [Amateur-repairs] Calibrating test equipment?
On Sun, Aug 3, 2025 at 11:57 PM don Root via groups.io <drootofallevil=teksavvy.com@groups.io> wrote:
Clint, how did you come by "my Rubidium time base."? The ones I see advertized would clean my pockets out just for a down payment.
--π»π π VA3DRL [ GIO might place this at the bottom of Quoted text, and not my text]
--π»π π VA3DRL [ GIO might place this at the bottom of Quoted text, and not my text]
--π»π π VA3DRL [ GIO might place this at the bottom of Quoted text, and not my text]
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